Liebert 3000 Air Conditioner User Manual


 
Troubleshooting
61
Table 24 Dehumidification troubleshooting
Symptom Possible Cause Check or Remedy
No dehumidification
Control not calling for
dehumidification
Check monitor status.
Compressor contactor not pulling in See 6.4.8 - Compressor Functional
Check and Table 23.
Compressor won't run; fuse blown or
CB tripped
See 6.4.8 - Compressor Functional
Check and Table 23. Check fuses or
CBs and contacts. Check line voltage
Table 25 Glycol pump troubleshooting
Symptom Possible Cause Check or Remedy
Suddenly stops pumping Clogged strainer or impeller Clean out debris.
Suddenly slow pumping Clogged impeller, diffuser, or line Clean out debris and use strainer.
Excessive leakage around the pump
shaft while operating
Worn seal or packing Replace seal or packing.
Performance poor
Worn impeller or seal Replace with new impeller or seal.
Suction lift too high Relocate pump closer to supply.
Motor not up to speed; low voltage Larger lead wires may be required.
Check for proper line voltage (±10%).
Worn bearings Replace pump
Noisy operation
Worn motor bearings Replace pump
Low discharge head Throttle discharge-improve suction
conditions.
Debris lodged in impeller Remove cover and clean out.
Cavitating pumps Adjust system pressures.
Table 26 Infrared humidifier troubleshooting
Symptom Possible Cause Check or Remedy
No humidification
Humidifier pan not filling Check water supply.
Check fill valve operation
Check drain stand pipe adjustment
Check for clogged waterline
Control not calling for humidity Check monitor status
Humidity contact not pulling in Check visually. If contact is made,
check line voltage after contactor and
fuses or CBs.
Check for open humidifier safety stat.
Jumper between terminals P35-6 and
P35-15. If contactor pulls in, replace
safety. Remove jumper.
Humidifier bulb burned out Replace bulb. Loosen lead on old
bulb. Trim excess lead length on new
bulb to avoid shorts.