38
SERVICE HANDBOOK
Table 4-1: Troubleshooting Chart
Complaint Possible Causes Response
Unit operates long or continu-
ously (continued)
Refrigerated or air conditioned
space has excessive load or
poor insulation, or system in-
adequate to handle load
Refer to the OEM service infor-
mation
Evaporator coil iced Refer to the OEM service infor-
mation
Restriction in refrigeration sys-
tem
Refer to the OEM service infor-
mation
Dirty condenser Refer to the OEM service infor-
mation
Filter dirty Refer to the OEM service infor-
mation
Space or cabinet temperature
too high
System problems, such as:
1. Control setting too high
2. Expansion device restrict-
ed or too small
3. Cooling coils too small
4. Inadequate air circulation
Refer to the OEM service infor-
mation
Water leaked into refrigerant
side of a water-utilizing system
See "Servicing or Trouble-
shooting Water-Utilizing Sys-
tems: Preventing Explosions"
on pages 32-33. Also, refer to
the OEM service information
Suction line frosted or sweat-
ing
First measure superheat to
determine if line frosting or
sweating is due to floodback.
If floodback is confirmed, pos-
sible problems are:
1. Expansion valve passing
excess refrigerant or is
oversized
2. Expansion valve is stuck
open
3. Evaporator fan not run-
ning
4. Overcharge of refrigerant
Refer to the OEM service infor-
mation
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