CRR-20 & CRR-40, September 1999
µ
P-D Controller
Alarm Codes, Descriptions and Corrective Actions
4-55
Code
Description
Corrective Action
52
KVQ Valve System Failure (Pretrip)
• Perform a Full Pretrip Test to check KVQ valve
(Check or Shutdown Alarm)
operation.
• Indicates KVQ valve does not respond to
• Check the power module.
voltage pulse signal.
• Check controller using the Microprocessor Tester.
• If alarm occurs during a Pretrip test, a
dash (-) precedes the alarm code.
• Check the wiring to KVQ valve using unit wiring
diagrams and a digital multimeter.
-Disconnect KVQ valve leads and check circuit
resistance. The heater (voltage pulse signal) circuit
resistance should measure 20 ohms at 20 C (68 F).
The thermistor circuit resistance should measure
20,000 ohms at 20 C (68 F).
53
Heating Current Out-of-Range (Pretrip)
• Check for low supply power voltage.
(Check or Shutdown Alarm)
• Check the heater element current draw using the
• Indicates total unit current draw is not within
“REFRG HEAT” test in the Refrigeration Test
acceptable limits when the unit is in Heat mode.
submenu. Current draw should be 7 to 14.5
amperes at 480V. Current draw on each leg should
• If alarm occurs during a Pretrip test, a
be within 0.2 amperes of each other.
dash (-) precedes the alarm code.
• Visually inspect the heater contactor and evaporator
fan contactors (EFH or EFL).
• Check the output module and related circuitry using
“REFRG HEAT” in the Refrigeration Test submenu
to place the unit in Heat. Then confirm that output
LEDs AC7 and AC12 (or AC8) are ON.
• If current draw on each leg is not within 0.2 amperes
of each other during heater current draw test, check
the current transformer. Turn unit OFF and discon-
nect power supply. Disconnect plug on current
transformer and check the resistance of each prima-
ry winding. Resistance for each winding should be
43 +/- 0.5 ohms.
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