7_Service

Section 7

Service

EXPLOSION HAZARD Failure to follow this WARNING can result in death, serious personal injury and / or property damage. Never use air or gas mixtures containing oxygen (O₂) for leak testing or operating the product. Charge only with refrigerants R-134a or R-513A as specified for the unit model number: Refrigerant must conform to AHRI Standard 700 specification.

The scroll compressor achieves low suction pressure very quickly. Do not use the compressor to evacuate the system below 0 psig. Never operate the compressor with the suction or discharge service valves closed (frontseated). Internal damage will result from operating the compressor in a deep vacuum.

To prevent trapping liquid refrigerant in the manifold gauge set, make sure set is brought to suction pressure before disconnecting.

When charging the unit with R-513A refrigerant, charge as a liquid only. R-513A is an azeotrope blend containing R-1234yf and R-134a. Charging or topping off as a vapor will result in an incorrect mixture of blend in the system.

NOTE: Use a refrigerant recovery system whenever removing refrigerant. When working with refrigerants you must comply with all local government environmental laws. In the U.S.A., refer to EPA section 608.

7.1.1 Manifold Gauge Set

The manifold gauge set, as shown in Figure 7.1, connects to a refrigeration system to determine system operating pressures, add refrigerant charge and to equalize or evacuate the system. The manifold gauge set with self-sealing hoses and couplers is required for service of the models covered within this manual. The set is available from Carrier Transicold, part number 07-00294-00 or 07-00294-05 (metric). Hoses are refrigeration and/or evacuation hoses (SAE J2196/R-134a).

Figure 7.1 Manifold Gauge Set

fig_gauge-set-complete

The gauge set layout with hoses and couplings is shown in Figure 7.2. The gauge set connects to the service connections on the refrigeration unit using the blue and red hoses. Service connections are described in Section 7.1.3. The yellow hose is a utility connection that can be connected to a a refrigerant cylinder or vacuum pump.

Once connected, the following procedures can be performed:

•Checking system operating pressures. When the hand valves on the gauge set are frontseated (turned clockwise), the gauges will read system pressure.

•Removing refrigerant charge

•Evacuating and dehydrating the system

•Adding refrigerant charge

Turning the hand valves clockwise will frontseat the valve (closed) to read system pressures at the gauge.

Turning the hand valves counter-clockwise will backseat the valve (open) to allow flow to the rest of the gauge set and hoses.

Figure 7.2 Manifold Gauge Set Layout

manifold-gauge-set

1)Suction Pressure Gauge (low side)

2)Suction Hand Valve (low side)

3)Suction Hose (low side)

4)Suction Coupling (low side)

5)Utility connection

6)Discharge Pressure Gauge (high side)

7)Discharge Hand Valve (high side)

8)Discharge Hose (high side)

9)Discharge Coupling (high side)

- - - - -

7.1.2 Evacuating the Manifold Gauge Set

If a manifold gauge set is new or was exposed to the atmosphere, it will need to be evacuated to remove contaminants and air. This is done while the gauge set blue and red hoses are not connected to the service connections. Follow the procedure below. Refer to Figure 7.2 for reference.

1.Backseat (turn counterclockwise) both service couplings.

2.Midseat both hand valves.

3.Connect the yellow hose to a vacuum pump and refrigerant cylinder.

4.Evacuate to 10 inches of vacuum.

5.Charge with refrigerant to a slightly positive pressure of 0.1 kg / cm2 (1.0 psig).

6.Frontseat (turn clockwise) both hand valves.

7.Disconnect from the cylinder. The gauge set is now ready to use.

7.1.3 Service Connections

There are three service valves on the unit for connecting to the manifold gauge set and performing refrigerant service: compressor suction valve, compressor discharge service valve and the liquid line (king) service valve. The service valves are provided with a double seat and an access valve which enables servicing of the compressor and refrigerant lines. See Figure 7.3 for diagram.

See Section 3.4.1 for compressor suction and discharge valve.

See Section 3.4.2 for liquid line (king) valve.

Figure 7.3 Service Valve

service-valves

1)Access Valve

2)Stem Cap

3)Valve Stem

4)Compressor or Filter Drier Inlet Connection

5)Line Connection

- - - - -

Turning the service valve stem clockwise will frontseat the valve to close off the line connection and open a path to the access valve.

Turning the service valve stem counterclockwise will backseat the valve to open the line connection and close off the path to the access valve.

With the service valve stem midway between frontseat and backseat, both of the service valve connections are open to the access valve path. For example, the valve stem is first fully backseated when connecting a manifold gauge to measure pressure. Then, the valve is opened 1/4 to 1/2 turn to measure the pressure.

7.1.4Connecting the Manifold Gauge Set

Connection of the manifold gauge set is dependent on the procedure performed or components serviced.

For reading system pressures, performing a manual pump down, or checking refrigerant charge, the manifold gauge set connects to the suction service valve (blue hose) and discharge service valve (red hose):

•See Figure 7.4 for illustration.

For the procedure for adding a partial refrigerant charge, the manifold gauge set connects to the suction service valve (blue hose), discharge service valve (red hose) and refrigerant cylinder (yellow hose).

•See Figure 7.5 for illustration.

For the procedure for adding a full refrigerant charge, the manifold gauge set connects to the suction service valve (blue hose), liquid line service valve (red hose) and refrigerant cylinder (yellow hose).

•See Figure 7.6 for illustration.

For the procedure to evacuate and dehydrate the system, the manifold gauge set connects to the refrigerant recovery system (blue hose), vacuum micron gauge (red hose) and vacuum pump (yellow hose). The service valves (suction, discharge, liquid line) all connect with evacuation hoses directly to the vacuum pump.

•See Figure 7.7 for illustration.

Figure 7.4 Connection for Reading Pressures and Checking Charge

service-connections-1

1)Manifold Gauge Set

2)Discharge Service Valve

3)Suction Service Valve

4)Compressor

- - - - -

Figure 7.5 Connection for Adding a Partial Charge

service-connections2

1)Manifold Gauge Set

2)Discharge Service Valve

3)Suction Service Valve

4)Compressor

5)Refrigerant Cylinder

- - - - -

Figure 7.6 Connection for Adding a Full Charge (Liquid)

service-connections3

1)Manifold Gauge Set

2)Liquid Line Service Valve

3)Suction Service Valve

4)Compressor

5)Refrigerant Cylinder

- - - - -

Figure 7.7 Connection for Evacuation and Dehydration

service-connections4

1)Manifold Gauge Set

2)Liquid Line Service Valve

3)Discharge Service Valve

4)Suction Service Valve

5)Compressor

6)Vacuum Micron Gauge

7)Refrigerant Recovery System

8)Vacuum Pump

- - - - -

7.1.4.1 Connect the Manifold Gauge Set to Access Valves

1.Verify that both hand valves on the manifold gauge set are fully closed.

2.Remove the service valve stem cap and make sure the service valve is backseated.

3.Remove the service access valve cap.

4.Connect the hose coupling to the service access valve; blue for suction (low side), red for discharge (high side).

5.Repeat the steps to connect the gauges to both suction (low side) and discharge (high side).

7.1.4.2 Removing the Manifold Gauge Set from Access Valves

1.While the compressor is still ON, backseat the discharge (high side) service valve.

2.Midseat both gauge set hand valves and allow the pressure in the gauge set to be drawn down to suction (low side) pressure. This returns any liquid that may be in the discharge (high side) hose to the system.

To prevent trapping liquid refrigerant in the manifold gauge set, make sure set is brought to suction pressure before disconnecting.

3.Backseat the suction (low side) service valve.

4.Backseat both service couplings.

5.Frontseat both gauge set hand valves.

6.Remove couplings from the access valves.

7.Install both service valve stem caps and service port caps, finger-tight only.

7.1.5Reading System Pressures

1.Connect the manifold gauge set to the suction service valve and discharge service valve.

See Section 7.1.4.1 for procedure to connect to valves. See Figure 7.4 for connection diagram.

2.Make sure both hand valves on the manifold gauge set are fully closed.

3.To read suction pressure, turn the blue coupling (low side) knob clockwise to open the system to the manifold gauge set.

4.Slightly midseat the suction service valve to read system low side pressure at the manifold gauge set.

5.To read discharge pressure, turn the red coupling (high side) knob clockwise to open the system to the manifold gauge set.

6.Slightly midseat the discharge service valve to read system high side pressure at the manifold gauge set

7.1.6Refrigerant Charge

EXPLOSION HAZARD: Failure to follow this WARNING can result in death, serious personal injury and / or property damage. Never use air or gas mixtures containing oxygen (O2) for leak testing or operating the product. Charge only with refrigerants R-134a or R-513A as specified for the unit model number. Refrigerant must conform to AHRI Standard 700 specification.

7.1.6.1 Checking the Refrigerant Charge

1.Connect the manifold gauge set to the suction service valve and discharge service valve.

See Section 7.1.4.1 for procedure to connect to valves. See Figure 7.4 for connection diagram.

2.For units operating on a water-cooled condenser, change over to air-cooled operation. Disconnect the water supply and the discharge line to the water-cooled condenser. The refrigeration unit will shift to air-cooled condenser operation when the water pressure switch (WPS) closes.

3.Bring the container temperature to approximately 0°C (32°F). Let the unit stabilize. Then set the controller unit setpoint to -25°C (-13°F) and immediately check the fluid level.

The level on the receiver should be between the glasses. On units equipped with a water-cooled condenser, the level should be at the center of the glass. If the refrigerant level is not correct, see Section 7.1.6.2 and Section 7.1.6.3 to add or remove refrigerant as required.

7.1.6.2 Adding Refrigerant to System - Full Charge

1.Evacuate the unit and leave in a deep vacuum. See Section 7.1.8.2.

2.Place the refrigerant cylinder on a scale. Connect the manifold gauge set to the suction service valve, liquid line service valve and refrigerant cylinder. Purge the charging line at the liquid line service valve and then note the weight of the cylinder and refrigerant.

See Section 7.1.4.1 for procedure to connect to valves. See Figure 7.6 for connection diagram.

3.Open the liquid valve on the cylinder. Open the liquid line valve halfway and allow liquid refrigerant to flow into the unit until the correct weight of refrigerant has been added as indicated by scales

Charge amounts are found on in Section 3.9 and also on the unit nameplate, see Figure 2.1.

4.It may be necessary to finish charging the unit through the suction service valve in gas form, due to pressure rise in the high side of the system.

5.Backseat the liquid line service valve to close off the gauge port. Close the liquid valve on the cylinder.

6.Start the unit in cooling mode. Run for approximately 10 minutes and check the refrigerant charge.

7.Ensure that the indicator in the receiver sight glass is at the correct level when fully charged.

7.1.6.3 AddingRefrigerant to System - Partial Charge

1.Examine the refrigerant system for any evidence of leaks, and repair as necessary. See Section 7.1.7.

2.Maintain the conditions outlined in the beginning of this section. See Section 7.1.6.1.

3.Fully backseat the suction service valve and remove the service port cap.

4.Connect the charging line between the suction service valve port and the refrigerant cylinder.

5.Open the vapor valve.

6.Partially frontseat (turn clockwise) the suction service valve and slowly add charge until the refrigerant appears at the proper level.

NOTE: Be careful not to frontseat the suction valve fully. If the compressor is operated in a vacuum, internal damage may result.

7.1.7 Refrigerant Leak Checking

NOTE: Only refrigerant R-134a or R-513A as specified for the unit model number, should be used to pressurize the system. Any other gas or vapor will contaminate the system, which will require additional purging and evacuation of the system.

NOTE: The recommended procedure for finding leaks in a system is with an appropriate electronic leak detector. Testing joints with soapsuds is satisfactory only for locating large leaks.

1.If the system is without refrigerant, charge the system with refrigerant to build up pressure between 2.1 to 3.5 bar (30.5 to 50.8 psig). To ensure complete pressurization of the system, refrigerant should be charged at the compressor suction valve and the liquid line service valve. Remove refrigerant cylinder and leak-check all connections.

2.If required, remove refrigerant using a refrigerant recovery system and repair any leaks. Check for leaks.

3.Evacuate and dehydrate the unit. See Section 7.1.8.

4.Charge the unit with refrigerant. See Section 7.1.6.

7.1.8 Evacuation and Dehydration

Moisture is detrimental to refrigeration systems. The presence of moisture in a refrigeration system can have many undesirable effects. The most common are copper plating, acid sludge formation, “freezing-up” of metering devices by free water, and formation of acids, resulting in metal corrosion.

Tools Required:

•Refrigerant recovery system. Carrier part # 07-00609-00.

•Vacuum pump, 2 stage, 3 to 5 cfm capacity. Carrier part # 07-00176-11.

•Electronic micron vacuum gauge. Carrier part # 07-00414-00.

7.1.8.1 Preparation

1.Make necessary repairs to the unit and perform a refrigerant leak check to the system. See Section 7.1.7.

2.If possible, keep the ambient temperature above 15.6°C (60°F) to speed evaporation of moisture. If the ambient temperature is lower than 15.6°C (60°F), ice might form before moisture removal is complete. Heat lamps or alternate sources of heat may be used to raise the system temperature.

NOTE: Additional time may be saved during a complete system evacuation by replacing the filter drier with a section of copper tubing and the appropriate fittings. Installation of a new filter drier may be performed during the charging procedure.

7.1.8.2 Evacuating and Dehydrating - Complete System

1.Remove all refrigerant using the refrigerant recovery system. First recover liquid refrigerant from the receiver. Then, finish the recovery procedure in vapor mode.

Connect a manifold gauge set to a refrigerant recovery system (blue hose), electronic micron gauge (red hose) and a vacuum pump (yellow hose). Then, connect the suction service valve, discharge valve and liquid line service valve to the vacuum pump with service hoses suitable for evacuation.

See Figure 7.7 for connection diagram.

2.The recommended method to evacuate and dehydrate the system is to connect evacuation hoses at the compressor suction and liquid line service valve. Make sure the service hoses are suited for evacuation purposes.

3.Test the evacuation setup for leaks by backseating the unit service valves and drawing a deep vacuum with the vacuum pump and gauge valves open. Shut off the pump and check to see if the vacuum holds. Repair leaks if necessary.

4.Midseat the refrigerant system service valves.

5.Open the vacuum pump and electronic vacuum gauge valves, if they are not already open. Start the vacuum pump and evacuate the unit until the electronic vacuum gauge indicates 2000 microns. Close the electronic vacuum gauge and vacuum pump valves. Shut off the vacuum pump. Wait a few minutes to be sure the vacuum holds.

6.Break the vacuum with either clean refrigerant (R-134a or R-513A as specified for the unit model number) or dry nitrogen. Raise system pressure to roughly 0.14 bar (2 psig), monitoring it with the compound gauge.

7.If refrigerant was used, remove using a refrigerant recovery system. If nitrogen was used, relieve the pressure.

8.Repeat steps 5 and 6 one time.

9.Remove the copper tubing and change the filter drier. Evacuate unit to 500 microns. Close the electronic vacuum gauge and vacuum pump valves. Shut off the vacuum pump. Wait five minutes to see if vacuum holds. This procedure checks for residual moisture and/or leaks.

10.With a vacuum still in the unit, the refrigerant charge may be drawn into the system from a refrigerant container on weight scales.

7.1.8.3 Evacuating and Dehydrating - Partial System

1.If refrigerant charge has been removed from the low side only, evacuate the low side by connecting the evacuation set-up at the compressor suction valve and the liquid service valve but leave the service valves frontseated until evacuation is completed.

2.Once evacuation has been completed and the pump has been isolated, fully backseat the service valves to isolate the service connections and then continue with checking and, if required, adding refrigerant in accordance with normal procedures.

7.1.9Converting to R-513A or R1234yf Refrigerant

The OptimaLINE compressor, for models 701-001 to 099, is capable of being field converted to R-513A refrigerant
at a later date as requested by the unit owner.

The OptimaLINE compressor, for models 701-100 to 149, is capable of being field converted to R-513A or R1234yf refrigerant at a later date as requested by the unit owner.

Conversion from R-134a to R-513A:

To convert, purchase the R-513A Service Kit, part number 76-66719-00. This kit comes with complete instructions for conversion. Contact a Carrier Field Service engineer if more assistance is needed.

Conversion from R-134a to R1234yf:

To convert, purchase the R1234yf Service Kit, part number 74-00325-00. This kit comes with complete instructions for conversion. Contact a Carrier Field Service engineer if more assistance is needed.

NOTE: After conversion, the unit will have some new R1234yf related components and an updated model number in the range of 701-150 to 199 updated in the controller. The documentation for this R1234yf converted unit with model range of 701-150 to 199 will now be covered with a separate manual, T-384.

7.2 Compressor

Make sure the start/stop switch is OFF, unit circuit breaker (CB-1) is OFF and the power plug disconnected before servicing unit components or moving parts. Follow local lockout / tagout procedures for working on equipment.

The compressor can run at hot surface temperatures. A compressor shield is in place to prevent contact with the compressor.

Before disassembly of the compressor, be sure to relieve the internal pressure very carefully by slightly loosening the couplings to break the seal.

A hermetically sealed compressor that should not be opened and/or repaired. Doing so can cause a loss in performance and premature system failure due to the precision machinery and assembly required within the compressor. To repair the unit, remove the faulty compressor and replace with an approved Carrier compressor. If the return of the compressor is not required, follow local waste collection & recycling regulations in discarding the compressor.

7.2.1Replacing the Compressor

The compressor is a Samsung variable speed scroll compressor with rotalock connections for suction and discharge ports and the economizer port.

NOTE: DO NOT add any oil to the replacement compressor, as it is shipped with a full oil charge.

1.Turn the unit On “I” a the Start-Stop switch (ST) and run in full cool mode for 10 minutes.

2.Turn the unit Off “0” at the Start-Stop switch (ST), turn the circuit breaker (CB-1) Off and disconnect unit power.

3.Remove all remaining refrigerant from the compressor using a refrigerant recovery system. See Figure 7.7 for connection diagram.

4.Remove the compressor guard grille.

5.Open the variable frequency drive (VFD) service cover to gain access to the compressor wiring.

6.Disconnect the compressor wires on the VFD terminals making a note of the exact wire positions as the replacement compressor will need to be wired using the same connections.

7.Remove the compressor power cable from the conduit connection on the VFD, leaving the power cable attached to the compressor.

8.Remove the Rotalock fittings from the suction service and discharge service connections, and uncouple the economizer line from the compressor.

9.Remove and save the compressor mounting hardware, including the bushings.

10.Remove (slide out) the old compressor from the unit.

11.Wire tie the power cable to the compressor.

12.Slide the new compressor into the unit.

NOTE: DO NOT add any oil to the replacement compressor, as it is shipped with a full oil charge.

13.Reusing the hardware from the old compressor, place the washers on each side of the bushing, and the new Mylar washer on the bottom of it as shown in Figure 7.8. Install the four base mounting bolts loosely.

Figure 7.8 Compressor Base Mounting Hardware

Fig_compressor-exploded

1)Bolt, Shoulder

2)Washer, Lock

3)Washer, Plain

4)Washer

5)Washer

6)Bushing

- - - - -

14.Place the new Teflon seals at the compressor suction, discharge and economizer connections. Hand tighten all three connections.

15.Torque the four base-mounting screws to 58 Nm (43 ft-lbs.).

16.Torque the compressor ports / connections.

Service Valve / Connection	Torque Value
Suction Rotalock	143 to 161 Nm (106-119 ft-lbs.)
Discharge Rotalock	108.5 to 135.5 Nm (80-100 ft-lbs.)
Economizer Connection	108.5 to 135.5 Nm (80-100 ft-lbs.)

17.Re-connect the power cable from the compressor to the VFD.

18.Replace the filter drier. See Section 7.5.2.

19.Perform a leak check of the system. See Section 7.1.7

20.Evacuate the system to 1000 microns. if the unit was pumped down before the replaced compressor was removed. Otherwise, evacuate the complete unit and charge it with a full charge of refrigerant, as specified on the unit nameplate.

See Section 7.1.8 for evacuation procedure.

See Section 7.1.6.2 for adding refrigerant charge procedure.

21.Backseat all service valves, connect power to the unit and run for at least 20 minutes.

7.2.2Replacing the Variable Frequency Drive (VFD)

The compressor variable speed synchronous motor is driven by a variable frequency drive (VFD), shown in Figure 7.9.

NOTE: When a VFD fails, it can not be bypassed and therefore the compressor will not run.

Figure 7.9 Variable Frequency Drive (VFD)

Fig_vfd-pic

Electrical Hazard. After disconnecting the power supply, wait seven minutes before servicing the Variable Frequency Drive (VFD) to allow capacitors to completely discharge.

1.Turn the unit start-stop switch (ST) and unit circuit breaker (CB-1) off and disconnect power to the unit.

2.Remove the bracket / guard below the control box for better access to the VFD. Save the mounting hardware. Note: the compressor guard may also need to be removed to gain proper access.

front-unit-guard

3.Open the VFD service cover to gain access to the wiring.

VFD-cover-removed

4.Release both sets of wires (compressor power cable and line power cable) from the VFD terminals. Make a note of the exact wire position as the same connections must be done on the replacement VFD.

VFD-Connections

5.Remove both conduit connectors and cable assemblies from the VFD.

6.Carefully remove the VFD from the unit back wall by removing and saving the four mounting bolts.

7.Install and wire the new VFD by reversing the above steps

7.2.3Replacing the Variable Frequency Drive (VFD) Fan

The procedure to replace the VFD fan is detailed below. This procedure is also included in document # 98-02763-00 which is included with the VFD fan replacement service kit, part # 76-00932-00.

1.Turn the unit start-stop switch (ST) and unit circuit breaker (CB-1) off and disconnect power to the unit.

2.Remove the bracket / guard below the control box for better access to the VFD. Save the mounting hardware. Note: the compressor guard may also need to be removed to gain proper access.

front-unit-guard

3.Open the VFD service cover to gain access to the fan assembly.

VFD-cover-removed

4.Remove and save the fan bolt by using a Torx T25 screwdriver. Then, loosen and pull out the fan wire grommet.

vfd-fan-bolts

5.Remove (pull out) the red and black fan wires from the terminal.

vfd-fan-wires-remove

This is done by inserting a small flathead screwdriver in the terminal hole above the wire to be removed, followed by a gentle lifting the screwdriver until the terminal jaws open and the wire is free to be pulled out.

vfd-fan-wires-remove2

6.Pull up the fan lever lock, located in the bottom back corner.

vfd-fan-lever-lock

7.Pull the lower end of the fan assembly radially out. Use a screwdriver to pull out the fan assembly if needed.

VFD-fan-remove2

8.The replacement fan (part # 10-00560-31) comes with new wire grommet installed. Assemble the replacement VFD fan by reversing the order of the above steps:

a.Secure the fan by tightening the torx bolt. Use a T25 screwdriver to tighten the bolt. See step 4 above.

b.Verify that the fan wires (black and red) are properly routed and connected at the terminals (red wire in the red terminal and black wire in the blue terminal). See steps 5 and 6 above.

c.Verify the new wire grommet is correctly secured before installing the VFD service cover. See step 4.

d.Secure the bracket / guard removed in step 2 above using the same hardware.

7.2.4 Checking the High Pressure Switch

The high pressure switch (HPS) is not adjustable. It can be checked by connecting to a cylinder of dry nitrogen and checking when the switch opens and closes.

Do not use a nitrogen cylinder without a pressure regulator.

1.Set the nitrogen pressure regulator at 26.4 kg/cm² (375 psig) with the bleed-off valve closed.

2.Close the valve on the cylinder and open the bleed-off valve.

3.Open the cylinder valve. Slowly close the bleed-off valve to increase pressure on the switch. The switch should open at a static pressure up to 25 kg/cm² (350 psig). If a light is used, the light will go out. If an ohmmeter is used, the meter will indicate open circuit.

4.Slowly open the bleed-off valve to decrease the pressure. The switch should close at 18 kg/cm² (250 psig).

5.Remove the switch as outlined in Section 7.2.5.

6.Connect an ohmmeter or continuity light across the switch terminals. An ohmmeter will indicate no resistance. A continuity light will be illuminated if the switch closed after relieving compressor pressure.

7.Connect a hose to a cylinder of dry nitrogen. See Figure 7.10.

Figure 7.10 High Pressure Switch Testing with Nitrogen

hps-testing

1)Cylinder Valve

2)Cylinder Gauge

3)Pressure Regulator

4)Nitrogen Cylinder

5)Pressure Gauge
(0 to 36 kg/cm2 = 0 to 400 psig)

6)Bleed-Off Valve

7)1/4 inch Connection

- - - - -

7.2.5 Replacing the High Pressure Switch

1.Remove the refrigerant charge.

2.Disconnect wiring from defective switch. The high pressure switch is located on the discharge connection or line and is removed by turning counterclockwise.

3.Install a new high pressure switch after verifying switch settings.

4.Evacuate, dehydrate and recharge the system.

5.Start the unit, verify refrigeration charge and oil level.

7.3 Condenser Coil and Fan

The coil consists of a series of parallel copper tubes expanded into copper fins and formed into a “U” shape with the fourth side of the square formed by the support bracket. The fan rotates counter-clockwise (viewed from front of unit) to pull air through the coil, and discharges air horizontally through the front of the unit.

7.3.1Cleaning the Condenser Coil

To ensure optimal efficiency of the unit, the condenser coil must be cleaned at least once a year, but more frequent cleaning may be required depending on operating conditions. Clean with fresh water sprayed in the reverse direction of the air flow to remove any debris from the coil. Mains water pressure is sufficient, a high pressure washer is not required.

1.Turn the unit start-stop switch (ST) and unit circuit breaker (CB-1) off and disconnect power to the unit.

2.Remove the condenser fan grille.

3.Starting from the top of the coil, use a water hose with a nozzle to wash the coil from the inside out.

4.Systematically wash across the inside top face of the coil until the water runs clean.

5.Wash down the center section and then through the bottom of the coil. Continue washing until the water runs clear.

6.After the coil is clean, rinse the condenser fan to remove any dirt build up from the blades.

7.Replace the condenser fan grille ensuring that it is centered around the fan.

7.3.2 Removing the Condenser Coil

1.Using a refrigerant reclaim system remove the refrigerant charge.

2.Turn the unit start-stop switch (ST) and unit circuit breaker (CB-1) off and disconnect power to the unit.

3.Remove the condenser fan grille. Retain all bolts and washers for reuse.

4.Remove the condenser fan.

5.Remove the infill panels to the left and right of the condenser fan shroud.

6.Remove the condenser fan shroud.

7.Unplug the condenser fan motor.

8.Remove and retain sufficient putty from around the motor wire harness to allow the harness to be slid back through the side support bracket.

9.Cut the top and bottom drain lines midway between the side support bracket and the first cable tie, approximately 150mm (6”) from the side support bracket.

10.Remove and retain sufficient putty from around the drain lines to allow the tubes to be slid back through the side support bracket.

11.Remove the filter drier.

12.Unbraze the inlet connection to the coil.

13.Remove the cushion clamps securing the liquid line to the top and bottom receiver brackets. Retain all clamps and securing hardware.

14.Place a support under the condenser coil before releasing the coil from the frame.

15.Remove the lower mounting bracket bolts from the inside of the coil.

16.Remove the top mounting bracket bolts and grille extension mount from inside the coil.

17.Remove the side support bracket mounting bolts.

18.Slide the condenser assembly with the receiver out of the unit.

7.3.3Preparing the Condenser Coil

Before installing the new condenser coil, the receiver assembly and mounting hardware must be removed from the old coil assembly.

1.From the old coil, unbolt the receiver assembly from the side support bracket.

2.Unbraze the receiver assembly from the coil outlet line and remove from the coil assembly.

3.Unbolt the side support bracket from the top and bottom coil supports and remove from the old coil.

4.Refit the side support bracket to the new coil ensuring that the top and bottom are flush mounted with the coil support.

7.3.4Installing the Condenser Coil

Once the side support bracket has been secured to the new condenser coil, the entire assembly is ready to be installed into the unit.

1. Slide the new condenser coil into place ensuring the coil inlet connection is mated to the pipework and that the coil is fully supported.

2.Secure the condenser coil into the unit using the retained hardware; refit the mylar and fender washers:

a.Refit the side support bracket bolts.

b.Refit the top support bracket bolts as well as the top grille extension support.

c.Refit the bottom support bracket bolts.

3.Braze the condenser coil inlet connection.

4.Insert the receiver pipe work onto the coil outlet and loosely secure the receiver assembly to the side support bracket with the retained hardware.

5.Braze the outlet connection to the receiver assembly.

6.Install a new filter drier.

7.Replace the liquid line cushion clamps.

8.Secure the receiver assembly to the side support bracket.

9.Pressure / leak test the coil and filter drier connections. See Section 7.1.7.

10.Evacuate the entire unit. See Section 7.1.8.

11.Slide the top and bottom drain lines back into place through the side support bracket.

12.Using the two supplied straight connectors and contact adhesive, reconnect the drain lines.

13.Slide the condenser fan motor wiring harness back through the side support bracket and refit to the condenser motor.

14.Replace all wire ties that were removed to properly secure the drain line and wiring.

15.Reseal the wire harness and drain line penetrations with the putty.

16.Slide the condenser fan onto the motor shaft reversed but do not secure.

17.Refit the condenser fan shroud to the unit. Use the condenser fan as a guide to ensure the shroud is properly centered around the fan.

18.Remove the condenser fan, and place it on the shaft facing the correct direction. Adjust the fan to the correct position, 37mm (1.5”) from the fan shroud, see Figure 7.11.

Figure 7.11 Condenser Fan Position

condenser-fan-position

19.Use Loctite “H” on the fan set screws, and tighten.

20.Refit left and right infill panels.

21.Refit the condenser fan grille, ensuring the grille is properly centered around the condenser fan.

22.Evacuate the entire unit. See Section 7.1.8.

23.Recharge the unit with the charge shown on the unit serial plate. See Section 7.1.6. It is important for proper unit operation that the charge is weighed into the unit.

7.3.5Replacing the Condenser Fan Motor

1.Turn the unit start-stop switch (ST) and unit circuit breaker (CB-1) off and disconnect power to the unit.

2.Remove the condenser fan grille. Retain all bolts and washers for reuse.

3.Remove the condenser fan by loosening the two set screws.

4.Disconnect the condenser fan motor wiring.

Take necessary steps (place plywood over coil or use sling on motor) to prevent motor from falling into condenser coil.

5.Note the number of shims on each side of the motor. The same configuration is required to refit the new motor.

6.Remove the fan motor mounting hardware and remove the motor.

7.Loosely mount the new motor using new lock nuts.

8.Connect the fan motor wiring to the new fan motor.

9.Replace the shims in the same configuration as they were removed.

10.Tighten the fan motor mounting bolts to properly secure the motor.

11.To make sure that the motor is aligned properly, slide the condenser fan onto the motor shaft reversed but do not secure.

12.Rotate the fan to make sure the fan blades do not contact the shroud:

•If the fan motor is misaligned vertically, add or remove shims to align.

•If the fan motor is not properly centered, loosen the mounting bolts, and adjust the motor position on the bracket, and then secure the motor.

13.Remove the condenser fan, and connect the fan motor wiring to the fan motor.

14.Place the condenser fan on the shaft facing the correct direction. Adjust the fan to the correct position, 37mm (1.5”) from the fan shroud, see Figure 7.11.

15.Use Loctite “H” on the fan set screws, and tighten.

16.Refit the left and right infill panels.

17.Refit the condenser fan grille, ensuring the grille is properly centered around condenser fan.

7.4 Water-Cooled Condenser Cleaning

The water-cooled condenser (WCC) can accumulate rust, scale and slime on the water-cooling surfaces. This can interfere with the transfer of heat, reduce system capacity, cause higher head pressures and increase the load on the system. The condenser coil condition can be checked by comparing the leaving water temperature with the actual condensing temperature. A larger than normal difference between these two values, coupled with a small difference in temperature of entering and exiting condensing water, is an indication of a dirty coil. If the WCC is dirty, it may be cleaned and de-scaled.

Cleaning Supplies Needed:

•Oakite Aluminum Cleaner® 164, available as a powder in 20 kg (44 lb) pails and 205 kg (450 lb) drums.

•Oakite Composition No. 32, available as a liquid in cases, each containing 3.785 liters (4 U.S. gallon) bottles and also in carboys of 52.6 kg (116 lbs) net.

•Fresh clean water.

•Acid proof pump and containers or bottles with rubber hose.

NOTE: When Oakite Compound No. 32 is used for the first time, contact a local Oakite technical service representative for suggestions in planning the procedure.

7.4.1Cleaning Procedure Summary

1.Turn the unit off and disconnect main power.

2.Disconnect the water pressure switch tubing by loosening the two flare nuts. Install a 1/4 inch flare cap on the water-cooled condenser inlet tube (replaces tubing flare nut). De-scale tubing if necessary.

3.Drain water from the condenser tubing circuit.

4.Clean the water tubes with Oakite Aluminum Cleaner® 164 to remove mud and slime.

5.Flush.

6.De-scale the water tubes with Oakite No. 32 to remove scale.

7.Flush.

8.Neutralize.

9.Flush.

10.Put the unit back in service under normal load and check head (discharge) pressure.

7.4.2Cleaning Procedure Detailed

1.Drain and flush the water circuit of the condenser coil. If scale on the tube inner surfaces is accompanied by slime, a thorough cleaning is necessary before de-scaling process can be accomplished.

2.To remove slime or mud, use Aluminum Cleaner® 164. Mix 170 grams (6 ounces) per 3.785 liters (1 U.S. gallon) of water. Mix cleaner in one half the volume of water, while stirring, and then add remaining water. Warm this solution and circulate through the tubes until all slime and mud has been removed.

3.After cleaning, flush the tubes thoroughly with fresh clean water.

4.Prepare a 15% by volume solution for de-scaling, by diluting Oakite Compound No. 32 with water. Do this by slowly adding 0.47 liter (1 U.S. pint) of the acid (Oakite No. 32) to 2.8 liters (3 U.S. quarts) of water.

Oakite No. 32 is an acid. Be sure that the acid is slowly added to the water. DO NOT PUT WATER INTO THE ACID - this will cause spattering and excessive heat.

Wear rubber gloves and wash the solution from the skin immediately if accidental contact occurs. Do not allow the solution to splash onto concrete.

5.Fill the tubes with this solution by filling from the bottom.

NOTE: It is important to provide a vent at the top for escaping gas.

6.Allow the Oakite No. 32 solution to soak in the tube coils for several hours, periodically pump-circulating it with an acid-proof pump.

An alternate method may be used whereby a pail, filled with the solution and attached to the coils by a hose can serve the same purpose by filling and draining. The solution must contact the scale at every point for thorough de-scaling. Air pockets in the solution should be avoided by regularly opening the vent to release gas. Keep flames away from the vent gases.

7.The time required for de-scaling will vary, depending upon the extent of the deposits. One way to determine when de-scaling has been completed is to titrate the solution periodically, using titrating equipment provided free by the Oakite technical service representative. As scale is being dissolved, titrate readings will indicate that the Oakite No. 32 solution is losing strength. When the reading remains constant for a reasonable time, this is an indication that scale has been dissolved.

8.When de-scaling is complete, drain the solution and flush thoroughly with water.

NOTE: If condenser cooling water is not being used as drinking water or is not re-circulated in a closed or tower system, neutralizing is not necessary.

9.Following the water flush, circulate a 56.7 gram (2 ounce) per 3.785 liter (1 U.S. gallon) solution of Oakite Aluminum Cleaner® 164 through the tubes to neutralize. Drain this solution.

10.Flush the tubes thoroughly with fresh water.

11.Put the unit back in service and operate under normal load. Check the head pressure. If normal, a thorough de-scaling has been achieved.

7.5 Filter Drier

The filter drier, as shown in Figure 7.12, should be replaced any time the system is opened for service.

Figure 7.12 Filter Drier

Fig-filter-drier

7.5.1Checking the Filter Drier

1.Test for a restricted or plugged filter drier by feeling the liquid line inlet and outlet connections. If the outlet side feels cooler than the inlet side, then the filter drier should be changed.

2.Check the moisture-liquid indicator. If it shows a high level of moisture, the filter drier should be replaced.

7.5.2 Replacing the Filter Drier

1.Evacuate the unit. See Section 7.1.8.

2.Replace the filter drier. Torque to 43-47 Nm (32-35 ft-lbs).

3.Recharge the unit. See Section 7.1.6.

4.After unit is in operation, inspect for moisture in the system and check charge.

7.6Pressure Relief Valve

The pressure relief valve (PRV) is installed in place of the fusible plug. See Figure 3.12 for location.

There are no serviceable parts on a pressure relief valve (PRV). Attempting to repair or alter the PRV is not permitted. If the PRV has released pressure, the entire PRV must be replaced.

7.6.1Replacing a Pressure Relief Valve (PRV)

1.Remove the refrigerant charge from the unit. See Section 7.1.6.

2.Remove the PRV.

3.Verify no contaminants have entered into the orifice.

4.Install an O-ring on the PRV.

5.Install a new PRV using correct torque. Wrench on 1.25” hexagon flats only, do not wrench on round
surfaces. See Section 3.9 for torque requirements.

6.Evacuate and dehydrate the system. See Section 7.1.8.

7.Recharge the system. See Section 7.1.6.

8.Start the unit and then verify refrigeration charge.

7.7 Evaporator Coil, Heaters and Fan

The evaporator coil should be cleaned regularly. The preferred cleaning fluid is fresh water or steam. Another recommended cleaner is Oakite 202 or similar, following manufacturer’s instructions.

The two drain pan hoses are routed behind the condenser fan motor and compressor. The drain pan line(s) must be open to ensure adequate drainage.

7.7.1Evaporator Section Cleaning

Container units that are exposed to certain fumigants may develop visible surface corrosion. This corrosion will show up as a white powder found on the inside of the container and on the evaporator stator and fan deck.

Analysis by Carrier Transicold environmental specialists have identified the white powder as consisting predominantly of aluminum oxide. Aluminum oxide is a coarse crystalline deposit most likely the result of surface corrosion on the aluminum parts within the container. If left untreated over time, it may build up in thickness and eventually flake as a light-weight white powder.

The surface corrosion of aluminum is brought about by exposure to chemicals such as sulfur dioxide and possibly other fumigants that are commonly used for fumigation and protection of some perishable cargo such as grapes, for example. Fumigation is the process by which a chemical is released into an enclosed area to eliminate infestations of insects, termites, rodents, weeds and soil-born disease.

Typically any aluminum oxide that becomes detached from evaporator fan stators will be blown into the wet evaporator coil where it will be caught and then flushed out of the unit during routine defrost cycles.

However, it is still highly recommended that after carrying cargo subject to fumigation procedures, that the inside of the unit be thoroughly cleansed prior to reuse.

Carrier Transicold has identified a fully biodegradable and environmentally safe alkaline cleaning agent (Tri-Pow’r® HD) for the unit. This will assist in helping to remove the corrosive fumigation chemicals and dislodging of the corrosive elements. This cleaner is available from the Carrier Transicold Performance Parts Group (PPG) and can be ordered through any of the PPG locations; Part Number NU4371-88.

As a general safety precaution, before using this product, refer to and retain the Material Safety Data (MSDS) sheet.

7.7.1.1 Cleaning Preparation

•Always wear goggles, gloves and work boots.

•Avoid contact with skin and clothing, and avoid breathing mists.

•When mixing, add water to the sprayer first, then the cleaner.

•ALWAYS provide for proper ventilation when cleaning indoor evaporator coils (rear doors must be open).

•Be aware of surroundings - food, plants, etc., and the potential for human exposure.

•Always read directions and follow recommended dilution ratios. More is not always better. Using non-diluted cleaner is not recommended.

7.7.1.2 Cleaning Procedure

1.Remove the upper evaporator access panel inside of the unit.

2.Spray the surface with water before applying the cleaning solution. This helps the cleaner work better.

3.Liberally apply the prepared cleaner solution (5 parts water and 1 part cleaner).

4.Allow the cleaner to soak in for five to seven minutes.

5.Assess area for rinsing. Follow all local regulations regarding disposal of waste water.

6.Thoroughly rinse the cleaner and surrounding area, floor, etc. When rinsing where heavy foaming solution is present, it is very important to take the time to thoroughly rinse the equipment and surroundings.

7.Always rinse the empty coil cleaner bottle, cap tightly and dispose of properly.

7.7.2Replacing the Evaporator Coil

1.Pump down the unit.

2.With power OFF and power plug removed, remove the screws securing the panel covering the evaporator section (upper panel).

3.Disconnect the defrost heater wiring.

4.Remove the mounting hardware from the coil.

5.Unsolder the two coil connections, one at the distributor and the other at the coil header.

6.Disconnect the defrost temperature sensor from the coil. See Section 7.10.

7.Remove middle coil support.

8.After defective coil is removed from unit, remove defrost heaters and install on replacement coil.

9.Install coil assembly by reversing above steps.

10.Leak check connections. Evacuate and add refrigerant charge.

7.7.3Testing the Evaporator Heaters

The heaters, see Figure 7.13, are wired directly back to the contactor and if a heater failure occurs during a trip, the heater set containing that heater may be disconnected at the contactor. The next pre-trip (P1) will detect that a heater set has been disconnected and indicate that the failed heater should be replaced.

Figure 7.13 Heater Arrangement

fig-heater-arrangement

1)Heater Element

2)Bracket

3)Retainer

- - - - -

All of the checks performed during this procedure should be carried out using a 500v Meg-ohm tester.

1.Connect the ground wire from the insulation tester to a fixed ground point, preferably the ground plate in the control box.

2.At the load side of the heater contactor, check the insulation resistance to ground.

If readings are > 2 Mohm, then the heaters are operating properly and no action is needed.

If readings are < 1 Mohm, then the faulty heater needs to be identified. Proceed to step 3 for units with a heater access panel or step 4 for units without a heater access panel.

If readings are between 1 and 2 Mohm, then the heaters need to be re-tested with the following steps:

a.Reconnect the unit to power and power the unit on.

b.Set the unit set point to a minimum of 10°C higher than the current temperature of the container. Allow the unit to go into heat mode, reach the temperature set point and maintain for 10-15 minutes.

c.Power the unit off. Allow the unit to cool to ambient temperature.

d.Connect the ground wire from the insulation tester to a fixed ground point, preferably the ground plate in the control box.

e.At the load side of the heater contactor, check the insulation resistance to ground.

If readings are > 1 Mohm, then the heaters are operating properly and no action is needed.

If readings are < 1 Mohm, then the faulty heater needs to be identified. Proceed to step 3 for units with a heater access panel or step 4 for units without a heater access panel.

3.Identify the faulty heater(s) for units with a heater access panel:

a.Open the access panel and cut out all wire splices to isolate all heaters inside of the unit.

b.Repeat the Megger test on each individual heater. Connect the ground clip to the outer metal sheath of the heater and the test clip to one of the wires from the same heater.

c.Replace any heater where the readings are < 1 Mohm.

4.Identify the faulty heater(s) for units without a heater access panel:

a.Remove all six connections from the Heater (HR) contactor load side, which splits the six heaters into three separate pairs.

b.Identify the following three wires: DHTL, DHML, DHBL. There is one from each load connection.

c.Repeat the Megger test on each pair of heaters to identify the faulty heater pair. Connect the ground clip from the insulation tester to a fixed ground point on the unit, preferably the ground plate in the control box. Connect the test clip to one of the wires stated above.

d.Test all three wires and replace any heater pair that has readings < 1 Mohm.

5.If the unit is loaded, and the heater can not be immediately replaced, perform the following steps:

a.Identify the wire at the opposite end of the faulty heater pair: DHTL - DHTR, DHML - DHMR, DHBL - DHBR.

b.Isolate the two wires.

c.Reconnect the remaining good wiring pairs to their original connections.

d.The unit will fail the PTI test P1-0 at the next pre-trip inspection. Repair action can be taken at that time.

6.If the unit is empty, replace the faulty heater:

a.With the heater pair identified, remove the upper back panel inside the container.

b.Identify the center point connection for the heater pair (black wiring from heaters) either against the unit back wall or in the wiring loom.

c.Cut the splice to separate the two heaters.

d.Carry out a Megger check on the two heaters in the same way as for units with heater panel. Replace any heater where the Megger readings are < 1 Mohms.

NOTE: If all heaters are above the acceptable limit with the wiring disconnected, then this indicates that the fault was in one or more of the wire splices that were removed.

e.Remove the hold-down clamp securing the heater(s) to the coil.

f.Verify that the heaters are not hot before handling them.

g.Lift the bent end of the heater (with the opposite end down and away from the coil). Move the heater to the side enough to clear the heater end support and remove.

h.To install heater, reverse steps.

i.Reconnect all wiring using new splices and heat shrink where needed. The heat shrink MUST have a 'melt-able' liner to ensure that the connections are properly sealed when shrunk. This can be seen as a 'Ring' of melt liner pushed from under the heat shrink at each end of the shrink tube.

NOTE: Failure to use melt liner heat shrink allows moisture to 'wick' up under the heat shrink and cause a leakage path.

7.7.4Replacing the Evaporator Fan Assembly

1.Remove the access panel by removing the mounting bolts and TIR locking device. Reach inside of the unit and remove the Ty-Rap securing the wire harness loop. Disconnect the connector by twisting to unlock and pulling to separate.

2.Loosen the four 1/4-20 clamp bolts that are located on the underside of the fan deck at the sides of the fan assembly. Slide the loosened clamps back from the fan assembly.

3.Slide the fan assembly out from the unit and place on a sturdy work surface.

7.7.5Disassembling the Evaporator Fan Assembly

1.Attach a spanner wrench to the two 1/4-20 holes located in the fan hub. Loosen the 5/8-18 shaft nut by holding the spanner wrench stationary and turning the 5/8-18 nut counter-clockwise.

2.Remove the spanner wrench. Use a universal wheel puller and remove the fan from the shaft. Remove the washers and key.

3.Remove the four 1/4-20 x 3/4 long bolts that are located under the fan that support the motor and stator housing. Remove the motor and plastic spacer.

7.7.6 Assembling the Evaporator Fan Assembly

1.Assemble the motor and plastic spacer onto the stator.

NOTE: When removing the black nylon evaporator fan blade, care must be taken to assure that the blade is not damaged. In the past, it was a common practice to insert a screwdriver between the fan blades to keep it from turning. This practice can no longer be used, as the blade is made up of a material that will be damaged. It is recommended that an impact wrench be used when removing the blade. Do not use the impact wrench when reinstalling, as galling of the stainless steel shaft can occur.

2.Apply Loctite to the 1/4-20 x 3/4 long bolts and torque to 0.81 mkg (70 inch-pounds).

3.Place one 5/8 flat washer on the shoulder of the fan motor shaft. Insert the key in the keyway and lubricate the fan motor shaft and threads with a graphite-oil solution (such as Never-seez).

4.Install the fan onto the motor shaft. Place one 5/8 flat washer with a 5/8-18 locknut onto the motor shaft and torque to 40 foot-pounds.

5.Install the evaporator fan assembly in reverse order of removal. Torque the four 1/4-20 clamp bolts to 0.81 mkg (70 inch-pounds). Connect the wiring connector.

6.Replace the access panel making sure that the panel does not leak. Make sure that the TIR locking device is lockwired. Torque the access panel hardware to 69 kg-cm (60 in/lbs.) using a crossing pattern as shown in Figure 7.14. Repeat the pattern twice for a proper seal.

Figure 7.14 Access Panel Torque Pattern

fig-access-panel-torque

7.8 E xpansion Valve (ECV / EEV)

The expansion valve, as shown in Figure 7.15, is an automatic device that maintains required superheat of the refrigerant. Unless the valve is defective, it seldom requires any maintenance other than periodic inspection to ensure that the thermal bulb is tightly secured to the suction line and wrapped with insulating compound.

Figure 7.15 Expansion Valve (ECV / EEV)

fig-exp-valve-service

1)Coil Boot

2)Coil

3)Expansion Valve

4)Strainer

- - - - -

The Economizer Expansion Valve (ECV), as shown in Figure 7.16, maintains superheat of the refrigerant gas leaving at the point of bulb attachment, regardless of suction pressure.

Figure 7.16 Economizer Expansion Valve (ECV)

Fig-Exv

The Electronic Expansion Valve (EEV, as shown in Figure 7.17, maintains superheat of the refrigerant gas leaving the evaporator. The valve functions are: (a) automatic response of refrigerant flow to match the evaporator load and (b) prevention of liquid refrigerant entering the compressor.

Figure 7.17 Electronic Expansion Valve (EEV)

Fig-EEV

7.8.1 Removing an Expansion Valve (ECV or EEV)

1.Pump down the compressor.

2.Frontseat both suction and discharge valves.

3.Turn unit power off and remove power from the unit.

4.Remove the coil.

5.Remove the valve. The preferred method of removing the valve is to cut the connection between the brazed section and the valve, using a small tube cutter. Remove the valve. Alternatively, use a wet rag to keep the valve cool. Heat inlet and outlet connections to valve body and remove valve.

6.Clean the valve stem with mild cleaner, if necessary.

7.8.2Installing an Expansion Valve (ECV or EEV)

1.Install the valve and a new strainer with the cone of the strainer / screen pointing into the liquid line at the inlet to the valve.

2.During installation, make sure the coil is snapped down fully, and the coil retention tab is properly seated in one of the valve body dimples. Also, ensure that coil boot is properly fitted over valve body.

3.Replace the filter drier. See Section 7.5.2.

4.Evacuate to 500 microns by placing the vacuum pump on the liquid line and suction service valve. See Section 7.1.8.

5.Open the liquid line service valve and check refrigerant level.

6.Check superheat.

7.Check unit operation by running a Pre-Trip inspection. See Section 4.5.

7.9 Controller Service Procedures

A controller self diagnostic test can be performed with function code Cd74. While the test is running, “tESt” will flash on the display. Once the test is complete, the Test Result will be displayed. After 30 seconds, the controller returns to displaying the setpoint.

7.9.1Handling Modules

Do not remove wire harnesses from circuit boards unless you are grounded to the unit frame with a static safe wrist strap or equivalent static drain device.

Remove the controller module and unplug all connectors before performing any arc welding on any part of the container.

The guidelines and cautions provided herein should be followed when handling the modules. These precautions and procedures should be implemented when replacing a module, when doing any arc welding on the unit, or when service to the refrigeration unit requires handling and removal of a module.

1.Obtain a grounding wrist strap (Carrier Transicold P/N 07-00304-00) and a static dissipation mat (Carrier Transicold P/N 07-00277-00). The wrist strap, when properly grounded, will dissipate any potential static buildup on the body. The dissipation mat will provide a static-free work surface on which to place and/or service the modules.

2.Disconnect and secure power to the unit.

3.Place strap on wrist and attach the ground end to any exposed unpainted metal area on the refrigeration unit frame (bolts, screws, etc.).

4.Carefully remove the module. Do not touch any of the electrical connections if possible. Place the module on the static mat.

NOTE: The strap should be worn during any service work on a module, even when it is placed on the mat.

7.9.2Replacing the Controller

Removal:

1.Disconnect all front wire harness connectors and move wiring out of the way.

2.The lower controller mounting is slotted. Loosen the top mounting screw, see Figure 4.1, and lift up and out.

3.Remove the module.

4.When removing the replacement module from its packaging, note how it is packaged. When returning the old module for service, place it in the packaging in the same manner as the replacement. The packaging has been designed to protect the module from both physical and electrostatic discharge damage during storage and transit.

Installation:

1.Install the module by reversing the removal steps.

2.Torque values for mounting screws, see Figure 4.1, are 0.23 mkg (20 inch-pounds). Torque value for the connectors is 0.12 mkg (10 inch-pounds).

7.9.3 Replacing the Battery

The Carrier rechargeable battery pack part # is 79-04262-01.

1.Turn unit power Off and disconnect the power supply.

2.Open the control box door and remove the high voltage shield (if installed).

3.Disconnect the battery connection at the "BA" connector and carefully remove wire ties along the battery wires leading back to the battery pack.

battery-BA-connector

4.Using a Driver Bit, Carrier Transicold part number 07-00418-00, loosen the left hand screw on the battery pack cover then remove the second screw on the outer edge of the battery pack cover.

battery-pack-cover

5.Remove the old battery from the bracket and assemble the new battery to the bracket.

6.Secure the battery wires from the battery along the previous route and then reconnect the BA connector. Heat shrink a ferrite clamp to the harness to reduce electromagnetic voltage transients onto this interface.

controller-battery-secure

7.Replace wire ties that were removed. Replace shields and close the control panel door.

7.9.4AC Line Filter

There is an AC Line Filter installed between the Control Transformer and the PW Connector on the ML5 controller. This filter reduces Electromagnetic Voltage Transients induced / coupled on to the 36 VAC Control Transformer secondary of the Transformer.

When the AC Line filter fails, 18 VAC will not be provided to the controller and the system will not power up. Checking for a nominal 36 VAC across the input and output of the filter will verify if the correct voltage is getting provided to the controller.

Apply power to the container, turn on the ST switch, and verify that 36 VDC is present across pins 1 and 3 on the AC Line Filter. Once input power is verified, check the power on the output of the filter on pins 2 and 4. Input and output voltages should match. If the control voltages do not match, or output power appears to be fluctuating, the filter capability of the power filter can be tested.

7.9.4.1 Testing the Filter

1.Disconnect power and lock out the Container.

2.Remove the AC Power Filter from the system. Disconnect all spade connectors from the power filter, then remove the ground wire on the right side (line output) of power filter.

line-filter-remove-filter

3.Remove the remaining mounting bolt on the left side (line input) and pull from the system control box.

line-filter-remove-bolt

4.With the power filter removed, check for a capacitance reading of 0.54 uF +/-10% across pins 1 and 3. And then across pins 2-4.

line-filter-capacitance

5.Each individual pin can also be verified between the ground pin #5 and 1, 2, 3, 4. Testing each individual pin to the ground pin should read a capacitance of 0.011 uF +/-10%. Note that meter to left reading in nF but passing value 0.01052 uF.

line-filter-test-pins

6.Final check on the power filter is to verify the discharge resistor on the power filter output. Check resistance between pins 2 and 4 on the load side of the power filter for 330kΏ +/- 10%.

line-filter-test-resistance

7.Reinstall the power filter. Install the right side of the power filter to the bracket with ground leads.Then, install the mounting screw on the right side of the power filter.

line-filter-reinstall

8.Connect wires to the power filter using the hot stamping on the wire harness and pin marking on the power filter.

Line or Load	Wire	Filter
Line	PF5-TRX2 to	Pin 5
Line	PF3-TRX3 to	Pin 3
Line	PF1-TRX4 to	Pin 1
Load	ST5-PF2 to	Pin 2
Load	ST2-PF4 to	Pin 4

7.9.4.2 Filter Emergency Bypass Procedure

1.Connect the following with a 7.5 Amp automotive type fuse and cover the connections with electrical tape:

•PF1-TRX4 to ST5-PF2

•PF3-TRX3 to STS2-PF4

Line-filter-bypass-fuse

7.10Controller Programming Procedures

Refer to the T-372PL parts manual for a list of available tools for interfacing with the ML5 controller.

Notes Regarding USB Devices:

•The USB must have an ML5 software file or ML5 configuration file on the root level. If not, the “SEt UP” menu will not be accessible from underneath the “USb” menu.

•If more than one configuration database file is on the USB device at the root level, then only the file with the latest date will be considered.

•During a programming procedure, if “no USb” is displayed, wait up to 15 seconds for this message to be replaced with a different message. If the “no USb” message continues, remove and insert the USB device.

7.10.1Downloading DataCORDER Data to a USB Device

1.Turn unit power on (“I”) at the Start-Stop switch (ST). Wait for controller information to be displayed.

2.Insert the Micro USB drive (part # 12-50173-00) into the controller micro USB port.

3.Press the ALT. MODE key on the keypad.

4.Use the Arrow keys until “USb” is displayed, then press the ENTER key.

5.Use the Arrow keys until “dn LoAd” is displayed, then press the ENTER key.

6.The Download Menu is now displayed. The amount of free space available on the drive is displayed first. Use the Arrow keys to scroll down through the choices: ALL, trIP, 30dAy, 60dAy, 90dAy and 180.

7.Confirm the selection by pressing the ENTER key. The download starts.

8.When the download is complete, the display will show “dLOAd donE”.

9.Remove the USB flash drive from the USB port.

7.10.2 Uploading Controller Software from a USB Device

Refer to Carrier’s YouTube Channel to watch a video of this procedure.

1.Turn unit power on (“I”) at the Start-Stop switch (ST). Wait for controller information to be displayed.

2.Insert the Micro USB drive (part # 12-50173-00), pre-loaded with controller software, into the controller Micro USB port.

3.Press the ALT. MODE key on the keypad.

4.Wait for the display to show “USb” or use Arrow keys to show “USb”, then press the ENTER key.

5.Use the Arrow keys until “UP LoAd” is displayed, then press ENTER.

6.“LoAd XXXX” is now on the display. If more than one ML5 software revision file is on the USB flash drive at the root level, press the Arrow keys until the desired revision is displayed.

7.Press the ENTER key to load the software to the controller. The display will flash “LoAd SoFt”.

8.When “CAn PULL” and “USb noW” appears on the displayed, remove the USB drive from the port.

9.The display will flash “Pro SoFt”, then display “rE StArt” and “StArt UP” after that.

10.When the controller restarts, the following are displayed in order: the Unit ID (Cd40), software version (Cd18), configuration number (Cd20) and configuration file date. And finally the message “Pro donE”. The software has been loaded.

11.Bring up function code Cd 18 to confirm the correct software revision.

7.10.3Uploading a Software Configuration from a USB Device

Refer to Carrier’s YouTube Channel to watch a video of this procedure.

1.Turn unit power on (“I”) at the Start-Stop switch (ST). Wait for controller information to be displayed.

2.Insert the Micro USB drive (part # 12-50173-00), pre-loaded with software configuration files, into the controller Micro USB port. The software files will have an ml5 extension (.ml5).

3.Press the ALT. MODE key on the keypad.

4.Wait for the display to show “USb” or use Arrow keys to show “USb”, then press the ENTER key.

5.Use the Arrow keys until “SEt UP” is displayed, then press the ENTER key.

6.Use the Arrow keys until “run COnFG” is displayed, then press the ENTER key.

7.The display module will go blank briefly and then display “571 XXX”.

8.Use the Arrow keys to scroll through the list to obtain the proper model number, then press ENTER. The model number can be found on the unit nameplate.

IMPORTANT:

For units with software 6320 or greater loaded, when model numbers 571-113 or 571-123 are chosen the left display will show “rU” “SurE” and the right display shows “yES”. This is an attempt to prevent users from installing a customer specific configurations which CAN NOT be changed once entered. Use the Arrow keys to toggle selection between “yES” and “nO” and press ENTER to confirm. If “yES” is selected, any attempt afterwards to load a different model number will result in a “LoAd bAd” message. If “nO” is selected, the display returns to the main configuration menu.

9.Once the model number is selected, the display will show the message “rE StArt” briefly, and then “StArt UP” while the controller restarts. Do not take action during this time.

10.When the controller restarts, the following are displayed in order: the Unit ID (Cd40), software version (Cd18), configuration number (Cd20) and configuration file date. Remove the USB drive from the port.

11.Bring up function code Cd20 to confirm that the correct model configuration was loaded. The model should match what is shown on the unit nameplate.

7.10.4 Setting the Date and Time

1.Turn unit power on (“I”) at the Start-Stop switch (ST). Wait for controller information to be displayed.

2.Insert the designated USB flash drive into the controller micro USB port.

3.Press the ALT. MODE key on the keypad.

4.Use the Arrow keys until “USb” is displayed, then press the ENTER key.

5.Use the Arrow keys until “SEt UP” is displayed, then press the ENTER key.

6.Use the Arrow keys until “SEt tIM” is displayed, then press the ENTER key.

7.The date values are displayed in YYYY MM-DD format. Configure the date using the keypad.

•The values will be edited from left to right: the year first (YYYY), then month (MM) and then day (DD).

•Press the Arrow keys to increase or decrease a date value.

•Press the ENTER key to confirm the date value being modified and bring up the next value for editing.

•Press the CODE SELECT key to return to the previous date value.

8.Once date editing is complete and the day (DD) value is selected, press the ENTER key.

9.The time values are now displayed in HH MM format. Configure the time using the keypad.

•The values will be edited from left to right: the hours first (HH), then minutes (MM).

•Press the Arrow keys to increase or decrease a time value.

•Press the ENTER key to confirm the time value being modified and bring up the next value for editing.

•Press the CODE SELECT key to return to the previous time value.

10.Once time editing is complete, with the minutes (MM) value active, press the ENTER key.

11.The display returns to the USb menu. The date and time will be committed when the ENTER key is pressed.

7.10.5 Setting the Container ID

This procedure explains how to set the Container ID, which can be found in Function Code Cd40. The characters will be preset to the container ID of the box that the refrigeration unit was originally commissioned in. If no ID has been loaded, Cd40 will show dashes as the ID will be invalid.

1.Turn unit power on (“I”) at the Start-Stop switch (ST). Wait for controller information to be displayed.

2.Insert the USB flash drive into the controller micro USB port.

3.Press the ALT. MODE key on the keypad.

4.Use the Arrow keys until “USb” is displayed, then press the ENTER key.

5.Use the Arrow keys until “SEt UP” is displayed, then press the ENTER key.

6.Use the Arrow keys until “SEt Id” is displayed, then press the ENTER key. The current ID is displayed.

7.Configure the Container ID using the keypad.

•The first four characters are Alpha type and the last seven are numeric.

•The character being modified will always be on the right most position on the display.

•Press the Arrow keys to scroll through the selectable characters available.

•Press the ENTER key to confirm the choice and shift the selected character one position to the left to modify the next character.

•Press the CODE SELECT key to shift the characters one position to the right (backspace) to modify the previous character.

8.When the last value of Container ID is entered, press the ENTER key to enter the information to the controller.

7.11 Temperature Sensor Service

Service procedures for the following temperature sensors are provided in this section:

•Supply (STS / SRS)

•Return (RTS / RRS)

•Ambient (AMBS)

•Defrost (DTS)

•Evaporator (ETS)

•Compressor Discharge (CPDS).

7.11.1Preparing an Ice-Water Bath

The ice-water bath is a method for testing the accuracy of sensors by submerging the sensors in an insulated container with ice cubes or chipped ice, then filling voids between ice with water and agitating until mixture reaches 0°C (32°F) measured on a laboratory thermometer.

Notes:

•Wherever possible, use a thermometer that is regularly calibrated by an accredited test lab. Contact your instrument representative if the reference thermometer is not showing correct readings.

•Always use a temperature measurement reference instrument which is of higher accuracy than the device checked – for e.g., a thermometer with a rated accuracy of +/- 0.2 °C should be used to check a device with a rated accuracy +/- 0.3 °C.

•A thermally insulated container, tub open to atmosphere and large enough to contain crushed ice and water should be used. The tub should be large enough to contain the unit’s sensor and the reference thermometer.

•Enough distilled water should be available to make ice cubes and to set up a proper and stable ice-water triple-point mixture. Prepare ice using distilled water.

•Pre-cool distilled water for testing.

Procedure:

1.Prepare a mixture of clean ice using distilled water in a clean insulated container. If possible, the person handling should be wearing latex gloves.

a.Crush or chip the ice to completely fill the container. Finer ice particles will produce a more accurate mixture.

b.Add enough pre-cooled distilled water to fill the container.

c.Stir the mixture for a minimum of 2 minutes to ensure water is completely cooled and mixture is good.

d.The mixture should generally contain about 85% ice with distilled water occupying the rest of the space.

e.Add more ice as the ice melts.

2.Stir the ice water slurry mixture to maintain a temperature 0°C (32°F).

3.Constantly monitor the temperature of the ice water slurry with your reference thermometer. Ensure that the temperature of the bath has stabilized. The criterion for stability generally is to take two readings at 1 minute intervals, and the two readings should give you 0°C (32°F).

7.11.2 Sensor Checkout Procedure - Ice-Water Bath

This procedure is to verify the accuracy of a temperature sensor by placing in an ice-water bath.

1.Remove the sensor and place in a 0°C (32°F) ice-water bath. See Section 7.10.1 for ice-water bath preparation.

2.Start the unit and check the sensor reading on the control panel. Readings should be 0°C (32°F). If the reading is correct, reinstall the sensor. If the reading is incorrect, continue with the next step.

3.If the reading is off slightly, then re-calibrate. If the reading is not within 0°C (32°F) +/- 0.25 degrees, replace the sensor and re-check.

7.11.3Sensor Checkout Procedure - Control Box

A sensor can be tested from the control box by utilizing the controller harness tool, see Figure 7.18, part number 76-50256-00. This tool reduces the risk of damaging the controller pins when probing the system harness.

This procedure is described in detail in TechLINE article TL004-2022.

Figure 7.18 Controller Harness Tool

Controller-Harness-Tool

1.Remove power from the unit and follow lockout / tagout regulations.

2.Disconnect the harness from the ML5 controller and install the harness tool.

Controller-Harness-Tool-install

3.Locate the proper wires to be ohmed by referring to the system schematic.

Controller-Harness-Tool-ohm

4.Check against the temperature resistance chart provided in Table 9–1 and Table 9–2.

7.11.4Supply and Return Sensor Calibration - GDP

European Commission GDP (Good Distribution Practices) guidelines, used worldwide, call for the equipment that controls or monitor environments where medicinal products are stored or transported be calibrated in accordance with pharmaceutical shipper specifications, typically every six months or annually.

This procedure explains how to perform a GDP calibration of the supply (STS / SRS) and return (RTS / RRS) sensors using DataLINE software version 3.1 or higher.

The calibration procedure should be conducted in pairs (STS / SRS, or RTS / RRS) and it is recommended to calibrate before the full pre-trip inspection.

Before removing the Supply or Return air sensors from the unit, turn the ON/OFF switch and circuit breaker to the OFF position. Disconnect the power plug from the unit. Follow proper lockout/tagout procedures to ensure the power cannot inadvertently be energized. It is important that all dismantling work is done and tools and personnel are away from the unit before powering on the unit for calibration.

When performing the Return Air Sensor calibration, disconnect both evaporator motors.

NOTE: Before proceeding with the calibration procedure, ensure that controller software version is 5368 or higher and DataLINE version 3.1 or higher is installed onto the download device. Only the latest DataLINE and controller software will allow users to carry out Good Distribution Practice (GDP) calibration. Do not downgrade the software after installing the latest software.

NOTE: Before proceeding with the calibration procedure, it is recommended to check the sensors by running pre-trip P5-0. This test checks the sensor values. If the test fails, identify and correct the faulty sensor and run the test again.

Tools Required:

•Socket screwdrivers set

•Phillips screwdriver

•Standard hand tools

•Interrogator cable

•Laptop with DataLINE 3.1 or above installed

•Clean insulated container for distilled water and ice

•A regularly calibrated reference thermometer, recommended to be of accuracy up to 2 decimal places.

GDP Calibration, Removing Supply Sensors (STS / SRS) from Unit:

1.Locate the supply sensors cover assembly on the suction side of the compressor. Remove the two fasteners securing the cover of the sensors.

Remove the cover and rotate the supply air sensors, STS / SRS, in a clockwise direction and remove the sensors from the sensor housing.

sts-srs

GDP Calibration, Removing Return Sensors (RTS / RRS) from Unit:

1.Remove both front access panels from the unit by removing 8 fasteners from each panel. Save all hardware for re-installation.

access-panel-fasteners

2.On the right side, disconnect the fan motor wiring, loosen the fastener and remove (slide) the evaporator motor from the unit.

remove-evap-motor

3.Loosen the fastener on the sensor bracket.

rts-rrs-sensor-bracket

4.Cut all the wire ties that are securing the sensors to the harness and remove sensor.

rts-rrs-remove-sensor

GDP Calibration, Perform Calibration:

Before powering on the unit, it is important to ensure that all dismantling work is done and tools are away and service personnel are not working on the unit at the time of power on.

1.Connect the interrogator cable to the interrogator port. Then, power on the unit.

2.From ContainerLINK application, open the Probe Calibration screen. If a pop-up window appears reminding the user to ensure proper ice bath temperature, click OK to acknowledge.

3.On the Probe Calibration screen, click on the Calibrate Supply Sensors or Calibrate Return Sensors button.

4.A Location of Service pop-up window will appear. In the appropriate fields, enter the Service Center Name and Service Center Location where the calibration is being performed. Then, click the Save button. If a pop-up window appears reminding the user to ensure proper ice bath temperature, click OK to acknowledge and remember to maintain the Ice bath at 0°C (32°F).

5.Prepare the ice-water bath. See Section 7.10.1 for Ice Bath Preparation procedure.

6.Place the ice bath in a location near sensors. For Return Sensors, place the ice bath on an elevated platform or ladder of appropriate height.

ice-bath-elevated

7.Once temperature stability is ensured, submerge the sensors in the ice water slurry. Make certain that the sensors do not contact the container sides or bottom, or each other. Continuously stir the slurry mixture during calibration.

8.Ensure that the Ice bath is at 0°C (32°F) using the calibrated reference thermometer. Make sure the thermometer is regularly maintained and cleaned.

Confirm that the sensor readings have stabilized and the sensors are within +/- 0.3°C (0.5°F). The readings can be taken from the Uncalibrated column in the Current Probe Offset Temperatures table.

9.After confirming the sensor readings have stabilized, click on the Start Calibration button. The process begins automatically and will complete in less than 5 minutes. Continue to stir the ice bath during the testing. Calibration fails if stability cannot be achieved or sensor offset is greater than 0.3°C (0.5°F).

10.Once the calibration has completed, a pop-up will appear with the message Calibrate Complete. Click OK to acknowledge and the results will then be displayed on the screen in the Results column. If the sensor can not pass calibration, then see Section 7.10.6 for sensor replacement procedures.

11.After completing the calibration, download a DCX file and check that all of the following event information is captured: service center name, location, the results of the calibration and the offset applied. The event is considered a success when all the intended sensors in calibration have passed.

7.11.5USDA Cold Treatment

Sustained cold temperature has been employed as a post-harvest method for the control of fruit flies and other insect genera. The commodity, insect species, treatment temperatures and exposure times are found in sections T107, T108, and T109 of the USDA Treatment Manual.

In response to the demand to replace fumigation with this environmentally sound process, Carrier has integrated Cold Treatment capability into its microprocessor system. These units have the ability to maintain supply air temperature within one quarter degree Celsius of setpoint and record minute changes in product temperature within the DataCORDER memory, thus meeting USDA criteria.

USDA Recording

A special type of recording is used for USDA cold treatment purposes. Cold treatment recording requires three remote temperature probes be placed at prescribed locations in the cargo. Provision is made to connect these probes to the DataCORDER via receptacles located at the rear left-hand side of the unit. Four or five receptacles are provided. The four 3-pin receptacles are for the probes. The 5-pin receptacle is for the Interrogator. The probe receptacles are sized to accept plugs with tri-cam coupling locking devices. A label on the back panel of the unit shows which receptacle is used for each probe.

The standard DataCORDER report displays the supply and return air temperatures. The cold treatment report displays USDA #1, #2, #3 and the supply and return air temperatures. Cold treatment recording is backed up by a battery so recording can continue if AC power is lost.

USDA Cold Treatment Procedure:

The following is a summary of the steps required to initiate a USDA Cold Treatment.

1.From the ContainerLINK application, navigate to the Container > System Configuration screen. Then, select the DataCorder Configuration tab.

2.Verify that the DataCORDER is configured as follows and then close all screens when finished:

•Configuration Option is set for USDA probes

•Logging interval is set for 60 minutes.

•DataCorder Sample Type is set to 2 Averaged 3-USDA.

•Resolution is set to Normal.

3.Prepare a proper ice bath and ensure that it has stabilized at 0°C (32°F) using a calibrated reference thermometer. See Section 7.10.1 for Ice Bath Preparation procedure.

4.Submerge the sensors in the ice bath. Make certain that the sensors do not contact the container sides or bottom, or each other. Continuously stir the slurry mixture during calibration.

5.Navigate to the Container > Probe Calibration screen. By default the screen should have the Auto Calibration option chosen. Click on Auto if it is not already selected. For Auto Calibration, the controller calculates the offsets for all probes using an assumed ice-bath temperature of 0.0°C (32°F).

6.Confirm that the sensor readings have stabilized and the sensors are within +/- 0.3°C (0.5°F). The readings can be taken from the Uncalibrated column in the Current Probe Offset Temperatures table.

7.After the sensor readings have stabilized, click the Start Calibration button. Probes are calibrated individually once they are determined to be stable. This calibration generates the probe offsets which, when entered into the controller by the user or automatically depending on how ContainerLINK is configured, are stored in the controller and applied to the USDA sensors for use in generating sensor type reports.

8.Pre-cool the container to the treatment temperature or below.

9.Install the controller battery pack (if not already installed). Then, check the battery status at code Cd19.

a.Press the CODE SELECT key on the display.

b.Use the Arrow keys to bring up Cd19 and press the ENTER key.

c.Use the Arrow keys to select bTEST and press the ENTER key. Refer to Cd19 description for more details and testing the battery

10.Place the three probes. Refer to the USDA Treatment Manual for directions on placement of probes in fruit and probe locations in container.

•Sensor 1: Place USDA 1 in a box at the top of the stack of fruit nearest to the air return intake.

•Sensor 2: Place USDA 2 slightly aft of the middle of the container, halfway between the top and bottom of the stack.

•Sensor 3: Place USDA 3 one pallet stack in from the container doors, halfway between the top and bottom of the stack.

11.Navigate back to the Container > System Configuration screen. Fill out the Trip Comment and ISO Trip Header information. Then, select Start New Trip to perform a Trip Start.

12.Bring up Code Cd51 on the unit display, enable Automatic Cold Treatment (ACT) and configure as required. See Section 5.9.3 for procedure.

7.11.6Replacing a Sensor

Always turn OFF the unit circuit breaker (CB-1) and disconnect main power supply before removing electrical parts.

NOTE: Include white date code label when cutting out and removing defective sensors. The label could be required for warranty returns.

Figure 7.19 Sensor Types

sensor-types

1.Turn unit power off (“0”) at the Start-Stop switch (ST). Disconnect the power supply.

2.Cut the cable. Slide the cap and grommet off the bulb type sensor and save for reuse. Do not cut the grommet.

3.Cut one wire of existing cable 40 mm (1-1/2 inches) shorter than the other wire.

4.Cut the replacement sensor wires (opposite colors) back 40 mm (1-1/2 inches). See Figure 7.19.

5.Strip back insulation on all wiring 6.3 mm (1/4 inch).

6.Slide a large piece of heat shrink tubing over the cable, and place the two small pieces of heat shrink tubing, one over each wire, before adding crimp fittings as shown in Figure 7.20.

Figure 7.20 Sensor and Cable Splice

sensor-cable-splice

1)Sensor (typical)

2)Large Heat Shrink Tubing (1)

3)Cable

4)Heat Shrink Tubing, 2 or 3 as required

- - - - -

7.If required, slide the cap and grommet assembly onto the replacement sensor.

8.Slip crimp fittings over dressed wires (keeping wire colors together). Make sure wires are pushed into crimp fittings as far as possible and crimp with crimping tool.

9.Solder spliced wires with a 60% tin and 40% lead Rosin-core solder.

10.Slide heat shrink tubing over each splice so that ends of tubing cover both ends of crimp as shown in Figure 7.20.

11.Heat tubing to shrink over splice. Make sure all seams are sealed tightly against the wiring to prevent moisture seepage.

Do not allow moisture to enter wire splice area as this may affect sensor resistance.

12.Slide large heat shrink tubing over both splices and shrink.

13.Position sensor in unit as shown in Figure 7.20 and re-check sensor resistance.

•Supply Sensor (STS / SRS) Positioning, see Figure 7.21

•Return Sensor (RTS / RRS) Positioning, see Figure 7.22

•Evaporator Temperature Sensor (ETS1 / ETS2) Positioning, see Figure 7.23

14.Reinstall the sensor.

•Supply Sensor (STS / SRS) Installation, see Section 7.10.7

•Return Sensor (RTS / RRS) Installation, see Section 7.10.8

•Defrost Termination Sensor (DTS) Installation, see Section 7.10.9

•Evaporator Temperature Sensor (ETS1 / ETS2) Installation, see Section 7.10.10

NOTE: The P5 Pre-Trip test must be run to deactivate probe alarms. See Section 5.7.

7.11.7Installing a Supply Sensor (STS / SRS)

To properly position a unit Supply Temperature or Supply Recorder sensor (STS / SRS), the sensor must be fully inserted into the probe holder. This positioning will give the sensor the optimum amount of exposure to the supply air stream, and will allow the Controller to operate correctly. Insufficient probe insertion into the probe holder will result in poor temperature control due to the lack of air flow over the sensor.

It is also necessary to ensure that the probe tip does not contact the back panel. The design minimum clearance of 6 mm (1/4 inch) should be maintained. See Figure 7.21.

Figure 7.21 Supply Sensor (STS / SRS)

supply-sensor-service

1)Sensor Wire

2)Cap & Grommet Assembly

3)Probe Holder

4)Evaporator Back Panel

5)Supply Sensor

- - - - -

7.11.8Installing a Return Sensor (RTS / RRS)

Reinstall the Return Temperature or Return Recorder sensor (RTS / RRS), as shown in Figure 7.22. For proper placement of the return sensor, be sure to position the enlarged positioning section of the sensor against the side of the mounting clamp.

Figure 7.22 Return Sensor (RTS / RTS)

return-sensor-service

7.11.9 Installing a Defrost Temperature Sensor (DTS)

The Defrost Temperature Sensor (DTS) must have insulating material placed completely over the sensor to ensure the coil metal temperature is sensed.

7.11.10Sensor (Installing an Evaporator Temperature ETS1 / ETS2)

The Evaporator Temperature Sensors (ETS1 / ETS2) are located in a tube holder under insulation, as illustrated in Figure 7.23. When the combo sensor is removed and reinstalled, it must be placed in a tube holder by applying thermal grease. Insulating material must completely cover the sensor to ensure the correct temperature is sensed.

Figure 7.23 Evaporator Temperature Sensor (ETS1 / ETS2)

ets-service

7.11.11Installing a Compressor Discharge Temperature Sensor (CPDS)

The Compressor Discharge Temperature Sensor (CPDS), see Figure 7.24, monitors refrigerant temperature in the dome of the compressor.

Figure 7.24 Compressor Discharge Temperature Sensor (CPDS)

cpds-service

1.Ensure the unit is disconnected from the power source.

2.Verify that the Start-Stop switch (ST) is in the “0” position.

3.Remove the existing sensor.

4.Clean all silicone sealer and dielectric compound from the sensor well. Make sure that the well is clean and dry. The top of the compressor, where the sensor seals, must also be clean and dry.

5.Using the syringe supplied with the replacement sensor, squeeze all of the dielectric compound into the sensor well.

6.Place a bead of the silicone sealer supplied with the replacement sensor around the sensor sealing ring. Insert sensor into the well with the leads parallel to the suction fitting.

7.Reconnect the sensor and run a Pre-Trip P5. See Section 4.5 for Pre-Trip Descriptions.

7.12Optional Sensors

7.12.1Humidity Sensor (HS)

The Humidity Sensor (HS) is an optional component that allows setting of a humidity set point in the controller. In dehumidification mode, the controller will operate to reduce internal container moisture level.

Figure 7.25 Humidity Sensor (HS)

hs-sensor

1)Cap opening (6 cm)

2)Cap hole (3 cm)

3)Humidity Sensor (HS)

4)Salt water solution

- - - - -

7.12.2Checking the Humidity Sensor

This procedure is to be performed in an effort to ease the troubleshooting of the humidity sensor. When performing this procedure and while working on the unit, always follow the proper lockout / tagout procedures.

Items Required:

•One 7/16” socket wrench or nut driver.

•One 1/4” socket wrench or nut driver.

•One clean, clear water bottle with a minimum 6 cm (2.5 in) opening and capacity to hold 500 ml (16.9 oz).

•100 ml (3.4 oz) of fresh water - distilled if available.

•50 gm of Salt (NaCl).

Procedure:

1.Remove the left Upper Fresh Air Makeup Vent panel.

2.Remove the humidity sensor from the mounting hardware and bring to the front of the access panel.

3.Disconnect the humidity sensor from the harness.

4.Drill a 3 cm (1.25 in) hole in the cap of a bottle.

5.Pour approximately 100 ml (3.4 oz) of water into the empty clean bottle.

6.Add salt to the water until it is present at the bottom of the bottle.

7.Cap the bottle and tape over the drilled hole.

8.Shake the bottle until the salt dissolves and water is saturated.

NOTE: To ensure saturation, add additional salt until it settles at the bottom without dissolving while shaking.

9.Remove the cap and insert the humidity sensor into the bottle through the bottle opening and pull the connector back through the drilled hole in the cap. Then, secure the cap and seal the wire going through the cap.

NOTE: Make sure that the sensor is not at all in contact with the salt water.

10.Allow the saturated salt mixture to settle for approximately ten minutes.

11.Reconnect the humidity sensor to the harness and power the reefer unit on.

12.Press the CODE SELECT key on the keypad.

13.Use the Arrow keys until “Cd17” is displayed then press the ENTER key.

14.This displays the humidity sensor reading. Verify the reading is between 60% and 85% relative humidity.

15.If the humidity sensor display is outside of this range, reconfirm the salt mixture and retest. If not in range, replace the sensor at the next opportunity.

16.Wipe clean and reinstall the humidity sensor and access panel. Torque the access panel hardware to 69 kg-cm (60 in.-lbs.) using a crossing pattern similar to the numbering below.

torque-sequence

17.If the panel gasket is damaged, replace it.

7.12.3Vent Position Sensor (VPS)

The optional vent position sensor (VPS) determines fresh air vent position in near real-time via function code Cd45.

The fresh air vent position sensor alarm (AL250) will occur if the sensor reading is not stable for four minutes or if the sensor is outside of its valid range (shorted or open). This can occur if the vent is loose or the panel is defective. To confirm a defective panel, assure that the wing nut is secure and then power cycle the unit. If the alarm immediately reappears as active, the panel should be replaced. The alarm should immediately go inactive. Check the four minute stability requirement. If the alarm reoccurs after the four minutes and the panel was known to have been stable, then the sensor should be replaced.

In order to replace the Upper VPS, the panel must be removed and replaced with another upper fresh air panel equipped with VPS. Upon installation, a new VPS assembly requires calibration.

7.12.3.1 Vent Position Sensor (VPS) Calibration

1.Rotate the vent to the 0 CMH / CFM position. Cd45 will automatically appear on the unit display.

2.Press and hold the ENTER key for five seconds.

3.After the ENTER key has been pressed the display will read “CAL” (for calibration).

4.Press and hold the ALT MODE key for five seconds.

5.After the calibration has been completed, Cd45 will display 0 CMH / CFM.

7.12.4Cargo Sensor

The optional cargo sensor should have an operational check performed while container box temperatures are above 3°C (37.4°F). Temperatures lower than this can cause frost build up on the cargo sensor lens, giving a false reading.

7.12.4.1 Cargo Sensor Operational Check

1.Insert and lock the new cargo sensor connector into the USDA Cargo Sensor Port (top port) ensuring pins are correctly aligned.

2.Turn unit power On. On the very first initial power on, the cargo will go into a service checkout (installation mode) for a duration of 30 minutes, updating every few seconds, for the checkout of the cargo sensor reading.

After this 30 minutes in the installation mode, the sensor goes into the normal function mode, updating the cargo status every 6 hours, whenever the controller is powered on.

To reinitialize the 30 minute installation mode, the battery within the cargo sensor needs to be removed and reinstalled.

3.Press the ALT. MODE key on the keypad.

4.Use the Arrow keys until “dC” is displayed, then press the ENTER key.

5.Use the Arrow keys until “dC14” is displayed, then press ENTER to display the readout.

6.The temperature displayed should fall within one of the temperature ranges listed in the table below. Check the table to see the recommended action to take. If battery replacement is necessary, ensure proper connections and a fresh set of batteries (kit number 76-00931-00) are installed.

Signal Range	Condition	Recommended Action
21 to 16°C	Cargo Sensor Fault	1. Verify wiring to interrogator port #4 inside container. 2. Check IR sensor window on cargo sensor for obstruction. 3. Replace cargo sensor.
14 to 9°C	Cargo present, battery low	No immediate action, replace battery before next trip
7° to 2°C	Cargo present	No action required
1° to -4°C	Cargo not present, battery low	No immediate action, replace battery before next trip
-6° to -11°C	Cargo not present	No action required
-14° to -49°C	Open circuit / dead battery	Replace battery with service kit 76-00931-00
-50°C	Interrogator installed incorrectly	Remove plug and reinstall with proper orientation.
33°C	Interrogator installed incorrectly	Remove plug and reinstall with proper orientation.

7.13EverFRESH® Service

Detailed procedures and technical information related to the EverFRESH controlled atmosphere system are included in the separate T-374 EverFRESH Manual. This can be found in the ContainerLINK™ app or from the Literature section of the Container Refrigeration website.

7.14Maintenance of Painted Surfaces

The refrigeration unit is protected by a special paint system against the corrosive atmosphere in which it normally operates. However, should the paint system be damaged, the base metal can corrode. In order to protect the refrigeration unit from the highly corrosive sea atmosphere, or if the protective paint system is scratched or damaged, clean the area to bare metal using a wire brush, emery paper or equivalent cleaning method. Immediately following cleaning, apply paint to the area, and allow to dry. Refer to the Parts List for proper paint selection.