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Controller Emergency Bypass Procedure
µ
P-D Controller
CRR-20 & CRR-40, September 1999
Controller Emergency Bypass Procedure
In the event the controller fails or the serial communications
link between the output module and the controller fails, the
output module will operate the unit as follows:
• Chill (Fresh) Loads: Output module STOPS all compressor
and fan motor operation.
• Frozen Loads: Output module operates unit in Full Cool
mode.
In the event of an emergency situation where the Output
Module also fails and replacement parts are not available, the
Emergency Bypass Module may be used to manually control
the unit.
NOTE: It may be necessary to partially close (manu-
ally) the liquid line service valve to regulate the flow
of refrigerant.
WARNING: High voltage (460/380 volts) is present on
the contactors and relays in the control box. To pre-
vent dangerous electrical shock, disconnect the sup-
ply power to the unit whenever possible when work-
ing in this area.
1.
Turn the Unit On/Off switch to OFF.
2.
Disconnect the unit power cord from the power supply.
3.
Disconnect wire harness connector “C1” from the bottom
of the Output Module and connect it to the bottom of the
Emergency Bypass Module.
NOTE: Make sure the Phase Rotation Switch on
the Emergency Bypass Module is OFF.
4.
Connect the unit power cord to the proper power supply.
5.
Turn the Unit On/Off switch to ON. The VIN LED on the
Emergency Bypass Module will turn ON to indicate
power is available at the module.
6.
Place the Phase Rotation Switch in the ABC position to
start the unit.
7.
a.
Place the Mode Switch to Full Cool position to oper-
ate compressor and condenser fan. Check condenser
fan airflow. Air should be blowing out from the cen-
ter of the grille.
b.
If air is NOT blowing out from the center of the
grille, place the Phase Rotation switch in the OFF
position. Allow the motors and fans to come to a
COMPLETE stop. Then place the Phase Rotation
switch in the CBA position. Check condenser airflow
again to confirm that air is blowing out from the cen-
ter of the grille.
8.
Use the Mode Switch to set unit operation for Evaporator
Fan Only or Full Cool operation.
CAUTION: The unit must be cycled manually to
maintain the desired temperature. Monitor con-
tainer temperature using the controller display (if
working) or an external thermometer.
Emergency Bypass Module
1. VIN LED
2. Mode Switch
3. High Pressure Cutout (HPCO) LED
4. 24 Vac LED
5. Phase Rotation Switch
6. Attach Wire Harness Connector C1 Here
Содержание CRR-20
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