Carrier PC211 specifications Other Problems/Malfunctions

Table 10N — Other Problems/Malfunctions

Description/	Probable Cause/Remedy
Malfunction
	Chilled water set point set too high. Access set point on LID and verify.
	Capacity override or excessive cooling load (machine at design capacity). Check
	LID status messages. Check for outside air infiltration into conditioned space.
	Condenser temperature too high. Check for proper flow, examine cooling tower
Chilled Water/Brine	operation, check for air or water leaks, check for fouled tubes.
	Refrigerant level low. Check for leaks, add refrigerant, and trim charge.
Temperature Too
	Liquid bypass in waterbox. Examine division plates and gaskets for leaks.
High (Machine
	Guide vanes fail to open. Use Control Test to check operation.
Running)
	Chilled water control point too high. Access control algorithm status and check
	chilled water control operation.
	Guide vanes fail to open fully. Be sure that the guide vane target is released.
	Check guide vane linkage. Check limit switch in actuator. Check that sensor is in
	the proper terminals.
Chilled Water/Brine	Chilled water set point set too low. Access set point on LID and verify.
	Chilled water control point too low. Access control algorithm status and check
Temperature Too	chilled water control for proper resets.
Low (Machine	High discharge temperature keeps guide vanes open.
Running)	Guide vanes fail to close. Be sure that guide vane target is released. Check chilled
	water sensor accuracy. Check guide vane linkage. Check actuator operation.
Chilled Water	Deadband too narrow. Configure LID for a larger deadband.
	Proportional bands too narrow. Either INC or DEC proportional bands should be
Temperature	increased.
Fluctuates. Vanes	Loose guide vane drive. Adjust chain drive.
Hunt	Defective vane actuator. Check through Control Test.
	Defective temperature sensor. Check sensor accuracy.
Low Oil Sump	Check for proper oil level (not enough oil). Check for proper refrigerant level (too
Temperature	much refrigerant).
While Running
(Less than 100 F
[38 C])
At Power Up,	Check for proper communications wiring on PSIO module. Check that the COMM1
Default Screen	communications wires from the LID are terminated to the COMM1 PSIO connec-
Does Not Appear,	tion.
‘‘Tables Loading’’
Message
Continually
Appears