CSR-20 & CSR-40, September 1999
Unit Description
Operating Modes
2-3
Power Line Communications Option
Several models of remote monitoring modems are available to
provide remote monitoring via the power cable. High or low
speed transmission reads all controller information.
• Thermo King Integrated Remote Monitor Unit (IRMU) for
ISO narrow band power line remote monitoring. The IRMU
is installed in a self-enclosed box bolted above the compres-
sor compartment.
• Sabroe Controls ISO wide band power line remote monitor-
ing modem is installed in the electrical control box.
• RTE ISO wide band or narrow band power line remote moni-
toring modem is installed in the electrical control box.
Redundant Sensors
Redundant return and supply air sensors are installed using the
USDA1 and USDA2 sensor ports.
• USDA1 = Return Air Sensor
• USDA2 = Supply Air Sensor
TRANSFRESH
®
Atmosphere Control System Options
Several TRANSFRESH options are available to meet individ-
ual customer needs. The TRANSFRESH system provides a
controlled atmosphere within the container. By controlling the
container temperature and atmosphere, the respiration rate of
fruit and vegetables can be lowered. This allows the product
quality to be maintained for longer periods of time.
• Provisions for the future installation and use of a TRANS-
FRESH atmosphere control system can be incorporated in
the unit. TRANSFRESH compatible A2 (power/defrost) and
A3 (communications) cables are factory installed.
• TRANSFRESH system components are installed for use of a
TRANSFRESH atmosphere control system. In addition to
A2 and A3 cables, the security frame, security enclosure with
insulation block, air hose and scrubber cable are factory
installed.
• TRANSFRESH Supplied Purge Port: A TRANSFRESH
supplied single purge port is factory installed. Port includes
a removable plug for charging the container with a modified
atmosphere.
Water-Cooled Condenser-Receiver Option
An optional water-cooled condenser-receiver tank provides the
unit with above deck and below deck operating capabilities. A
water pressure switch is provided on the water inlet line con-
nection. When water pressure is supplied to unit, the normally
closed water pressure switch opens. This causes the controller
to stop condenser fan operation.
Operating Modes
NOTE: See
µµ
P-D Controller chapter for complete
sequence of operation.
When the unit is started, two backlit LED displays on the
microprocessor illuminate. A sequence start of the required
loads occurs during initial start-up of the microprocessor and
when a control mode shift requires the compressor to start.
The digital displays indicate the setpoint temperature and the
controlling air sensor temperature as the microprocessor relays
and unit loads energize. The controlling sensor is determined
by the setpoint temperature:
Setpoint
Controlling Sensor
-9.9 C (14.1 F) and above
Supply Air Temperature
-10 C (14 F) and below
Return Air Temperature
The
µ
P-D controller uses a complex proportional-integral
derivative (PID) algorithm to provide accurate temperature
control in direct response to load demand. Therefore it is diffi-
cult to predict which operating mode the unit should be in by
comparing the setpoint to the return or supply air temperature.
The unit operates in either the Chill (Fresh) or Frozen mode.
Chill to Frozen mode transition point is -10 C (14 F).
Chill Loads: Controller Setpoint at -9.9 C (14.1 F) or
Above
Temperature control by the controller is based on the supply
air sensor temperature, the setpoint, the modulation tempera-
ture range and the pull-down rate. The evaporator fans operate
in high speed.
• Cool
• Modulation Cool
• Null (compressor stops, evaporator fans operate, if con-
denser fan is ON, it will operate for 30 seconds and then
stop)
• Heat (resistance heaters on, evaporator fans operate)
• Defrost (resistance heaters on, evaporator fans stop)
NOTE: If the Economy Mode is set to ON in the
Program menu of the
µµ
P-D controller, the evapo-
rator fans operate on low speed at setpoints of
-9.9 C (14.1 F) and above whenever the container
temperature is In-range.
