Table 10N — Other Problems/Malfunctions
Description/
Malfunction Probable Cause/R eme dy
Chilled Water/Br ine
Temperature Too
High (Machine
Running)
Chilled water set point set too high. Access set poi nt on LID and verify.
Capacity override or ex cessive cooling load (machi ne at design capacity). Check
LID status messages. Check for outside air infiltr ation into conditioned space.
Condenser temperature t oo high. Check for proper flow, examine cooling towe r
operation, check for air or water leaks, check for fouled tubes.
Refrigerant level low. Check for leaks, add refriger ant, and trim charge.
Liquid bypass in water box. Examine division plates and gaskets for leaks.
Guide vanes fail to o pen. Use Control Test to chec k operation.
Chilled water control p oint too high. Access c ontrol algorithm status and check
chilled water control operation.
Guide vanes fail to open f ully. Be sure that the guide vane target is released.
Check guide vane linkag e. Check limit switch in actu ator. Check that sensor is i n
the proper terminal s.
Chilled Water/Br ine
Temperature Too
Low (Machine
Running)
Chilled water set point set too low. Access set po int on LID and verify.
Chilled water control p oint too low. Access contr ol algorithm status and c heck
chilled water contro l for proper resets.
High discharge tempera ture keeps guide vanes open .
Guide vanes fail to c lose. Be sure that g uide vane target is releas ed. Check chilled
water sensor accuracy . Check guide vane linkag e. Check actuator operation .
Chilled Water
Temperature
Fluctuates. Vanes
Hunt
Deadband too narrow. Configure LID for a larger deadband.
Proportional bands too n arrow. Either INC or DEC p roportional bands should b e
increased.
Loose guide vane drive. Adjust chain drive.
Defective vane actuat or. Check through Control T est.
Defective temperature sensor. Check sensor accu racy.
Low Oil Sump
Temperature
While Running
(Less than 100 F
[38 C])
Check for proper oil l evel (not enough oil). Che ck for proper refrigerant l evel (too
much refrigerant).
At Power Up,
Default Screen
Does Not Appear,
‘‘Tables Loading’’
Message
Continually
Appears
Check for proper communications wiring on PSI O module. Check that the COMM1
communications wires from the LID are termina ted to the COMM1 PSIO connec -
tion.