Section 2
The Carrier Transicold model 69NT40-541-300/399 series units are of lightweight aluminum frame construction, designed to fit in the front of a container and serve as the container’s front wall.
They are one piece, self-contained, all-electric units, which include cooling and heating systems to provide precise temperature control.
The units are suppled with a complete charge of refrigerant R-134a and compressor lubricating oil, and are ready for operation upon installation. Forklift pockets are provided for unit installation and removal.
The base unit operates on nominal 380/460 volt, 3-phase, 50/60 hertz power. An optional autotransformer may be fitted to allow operation on nominal 190/230, 3 phase, 50/60 hertz power. Power for the control system is provided by a transformer, which steps the supply power down to 18 and 24 volts, single phase.
The controller is a Carrier Transicold Micro-Link 3 microprocessor. The controller operates automatically to select cooling, holding or heating as required to maintain the desired set point temperature within very close limits. The unit may also be equipped with an electronic temperature recorder.
The controller has a keypad and display for viewing or changing operating parameters. The display is also equipped with lights to indicate various modes of operation.
2.2Configuration Identification
Unit identification information is provided on a plate located near the compressor. The plate provides the unit model number, the unit serial number and the unit parts identification number (PID). The model number identifies the overall unit configuration while the PID provides information on specific optional equipment, factory provisions to allow for field installation of optional equipment and differences in detailed parts.
Units are equipped with either an aluminum or composite material box, and may be fitted with a lockable door.
The unit may be fitted with suction and discharge temperature sensors. The sensor readings may be viewed on the controller display.
The unit may be fitted with suction and discharge pressure gauges, suction and discharge transducers, or no pressure readout. The transducer readings may be viewed on the controller display.
The unit is fitted with a single speed reciprocating compressor.
The unit is fitted with a 3-row coil using 7mm tubing.
The evaporator section is equipped with a hermetic thermal expansion valve (TXV) and a heat exchanger. The unit may have six heaters.
Units are equipped with single-phase or three-phase evaporator fan motors. Opening of an evaporator fan internal protector will shut down the unit. Refer to Section 8 for schematic diagrams.
Two evaporator fan motor operation systems are available. On units with Normal Evaporator Fan Operation, opening of an evaporator fan internal protector will shut down the unit. On units equipped with Single Evaporator Fan Capability, additional relays are installed to allow the unit to continue to operate on a single fan.
Each unit is equipped with a tethered set of wiring schematic and wiring diagram plates. The plate sets are ordered using a seven-digit base part number and a two-digit dash number.
Various options may be factory or field equipped to the base unit. These options are described in the following sub-paragraphs.
The refrigeration controller may be fitted with standard replaceable batteries or a rechargeable battery pack. Rechargeable battery packs may be fitted in the standard location or in a secure location.
The unit may be fitted with a humidity sensor. This sensor allows setting of a humidity set point in the controller. In dehumidification mode the controller will operate to reduce internal container moisture level.
The unit may be supplied with fittings for additional temperature probes, which allow recording of USDA Cold Treatment data by the integral DataCORDER function of the Micro-Link refrigeration controller.
Units that use the DataCORDER function are fitted with interrogator receptacles for connection of equipment to download the recorded data. Two receptacles may be fitted; one is accessible from the front of the container and the other mounted inside the container (with the USDA receptacles).
The unit may be fitted with a remote monitoring receptacle. This item allows connection of remote indicators for COOL, DEFROST and IN RANGE. Unless otherwise indicated, the receptacle is mounted at the control box location.
Compressor-Cycle Perishable Cooling (CCPC) is a method of temperature control used during steady-state perishable cooling that cycles the compressor on and off according to supply / return air temperature conditions.
2.4.7Communications Interface Module
The unit may be fitted with a communications interface module. The communications interface module is a slave module which allows communication with a master central monitoring station. The module will respond to communication and return information over the main power line. Refer to the ship master system technical manual for further information.
An autotransformer may be provided to allow operation on 190/230, 3-phase, 50/60 hertz power. The autotransformer raises the supply voltage to the nominal 380/460 volt power required by the base unit. The autotransformer may also be fitted with an individual circuit breaker for the 230 volt power.
If the unit is equipped with an autotransformer and communications module, the autotransformer will be fitted with a transformer bridge unit (TBU) to assist in communications.
The unit may be fitted with an electronic temperature recording device.
Rain gutters may be fitted over the control box and recorder section to divert rain away from the controls. The different gutters include standard length bolted gutters, extended length gutters, and riveted gutters.
The unit may be equipped with handles to facilitate access to stacked containers. These handles may include fixed handles (located at the sides of the unit) and/or a hinged handle at the center (attached to the condenser coil cover).
The unit may be fitted with ports in the front of the frame for insertion of a thermometer to measure supply and/or return air temperature. If fitted, the port(s) will require a cap and chain.
The refrigeration system may be fitted with a water-cooled condenser. The condenser is constructed using copper-nickel tube for seawater applications. The water-cooled condenser is in series with the air-cooled condenser and replaces the standard unit receiver. When operating on the water-cooled condenser, the condenser fan can be deactivated by either a water pressure switch or condenser fan switch. Depending on the unit’s configuration and the compressor discharge temperature, the condenser fan may also be activated during water-cooled condenser operation.
Back panel designs that may be fitted include panels of aluminum and stainless steel. Panels may have access doors and/or hinge mounting.
Various power cable and plug designs are available for the main 460 volt supply. The plug options tailor the cables to each customer’s requirements.
Units equipped with an autotransformer require an additional power cable for connection to the 230 volt source. Various power cable and plug designs are available. The plug options tailor the cables to customer requirements.
Various designs are available for storage of the power cables. These options are variations of the compressor section front cover.
2.4.18Upper Air (Fresh Air Make Up)
The unit may be fitted with an upper fresh air makeup assembly. The fresh air makeup assembly is available with a vent positioning sensor (VPS) and may also be fitted with screens.
2.4.19Lower Air (Fresh Air Make Up)
The unit may be fitted with a lower fresh air makeup assembly. The fresh air makeup assembly is available with a vent positioning sensor (VPS) and may also be fitted with screens.
Operating instruction and function code listing labels will differ depending on the options installed. For example, additional operating instructions are required to describe start-up of a unit equipped with an autotransformer. Where the labels are available with additional languages, they are listed in the parts list.
Two different controllers are available:
1.Re-manufactured − Controller is the equivalent of a new OEM controller and is supplied with a 12 month warranty.
2.Repaired − Controller has had previous faults repaired and upgraded with the latest software.
Repaired controllers are NOT to be used for warranty repairs. Only full OEM re-manufactured controllers are to be used.
Controllers will be factory equipped with the latest version of operational software, but will NOT be configured for a specific model number and will need to be configured at the time of installation or sale.
The unit may be fitted with a backlit Liquid Crystal Display (LCD) or a Light Emitting Diode (LED) Display.
Two styles of condenser grilles are available − direct bolted grilles and hinged grilles.
The unit may be equipped with switches to allow emergency bypass of the controller. The EMERGENCY BYPASS switch functions to bypass the controller in the event of controller failure. The EMERGENCY DEFROST switch functions to bypass all controls and place the unit in the defrost mode.
The optional eAutoFresh venting system moderates the atmospheric level inside the container unit in response to cargo respiration.
To improve operation in cold ambients, the unit may be fitted with a crankcase heater. The crankcase heater is operated any time the unit is under power and the compressor is not running. The purpose of the heater is to warm the compressor oil and boil off any liquid refrigerant that may be present in the crankcase.
The unit may be fitted with a set of power factor correction capacitors to assist in correction of imbalance in current draw by the compressor.