2-2
General Description
Unit Description
CSR-20 & CSR-40, September 1999
Thermoguard
®
µµ
P-D Controller
The
µ
P-D controller incorporates refrigeration system compo-
nent control, thermostat, digital thermometer, fault indicator
and data recording capabilities into one self-contained pack-
age. The
µ
P-D controller provides accurate air temperature
control of perishable and frozen cargo.
The controller features a weather tight, corrosion resis-
tance enclosure. Two large alpha-numeric digital displays are
backlit and tilted for easy viewing. Ten control keys provide
quick access to unit operating information and easy comple-
tion of setpoint, manual defrost, pretrip and start-of-trip pro-
gramming.
A
µ
P-D output module is used by the controller to ener-
gize and de-energize various contactors and solenoids. An
LED indicator is included in each output circuit to show when
the output is energized. The
µ
P-D output module is located
inside the control box.
Indicator Lights
Indicator lights on the
µ
P-D controller signal Cool,
Modulation, Null, Heat, In-range, Defrost, Supply Air
Temperature, Return Air Temperature, Power Limit and
Alarm.
USDA Cold Treatment Temperature Recording
The
µ
P-D controller includes provisions for the use of three or
four USDA sensors. These sensors allow temperatures in vari-
ous areas of the load to be monitored and recorded for United
States Department of Agriculture use in monitoring Cold
Treatment shipments.
When a USDA sensor is installed, the controller will auto-
matically detect the sensors and activate data logging. The
controller Program menu shows the USDA sensor number in
the left display and “AUTO” in the right display if data log-
ging is active. However, the USDA program screen MUST be
set to ON, each USDA sensor MUST be calibrated, and each
sensor must be located in the load as shown in USDA direc-
tives to comply with USDA temperature recording require-
ments.
Auxiliary Battery and Battery Charger Option
An optional 12 Vdc, 7 or 12 amp hour battery provides power
for controller operation and datalogging when unit 460-380V
supply power is disconnected. A regulated battery charger
automatically maintains the battery charge when 460-380V
power is connected to the unit.
Dehumidification Control System Option
An optional dehumidification system lowers the relative
humidity in the container to the humidity setpoint. The control
range setpoint is adjustable between 50% and 100%.
Humidification Control System Option
An optional humidification system increases the relative
humidity in the container to the humidity setpoint. The control
range setpoint is adjustable between 50% and 100%.
Controlled Atmosphere System Option
An optional controlled atmosphere system includes two charg-
ing ports and a pressure relief valve to provide a modified
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.
Dual Voltage Option
A dual voltage system includes a 15 KVA auto transformer
and an 18.3 m (60 ft) power cable for operation on 230-
190V/3 Ph/60-50 Hz power. The power cable is stored below
the control box in the condenser section.
The 15 KVA auto transformer steps 230/190V power up
to 460/380V. The auto transformer includes a 460-380V/3
Ph/60-50 Hz power receptacle.
For operation on 230/190V power, plug the 460-380V
unit power cable into the receptacle on the auto transformer.
Then plug the 230/190V power cable into a 230-190V power
supply.
Remote Monitoring Receptacle (4-Pin) Option
An optional 4-pin remote monitor connector provides 24 Vac
signals for bridge lights that monitor Cool (Compressor On),
Defrost and In-range conditions.
Recording Thermometer Options
Several models of temperature recorders are available for
mounting on the unit. Each temperature recorder is designed
to withstand widely varying environments including low and
high ambient temperatures, salt water, humidity, fungus,
industrial pollutants, dynamic loading, rain, sand and dust.
• The 31-day Saginomiya Recorder is electric motor driven by
a dry cell type battery with a 1 year life expectancy.
• The 31-day Partlow Recorder is mechanically driven by a
spring mechanism.
