Shut Down on Maximum
Freeze Time (continued)
Compressor not operating
(continued)
Check compressor temperature
Check compressor voltage
Check compressor windings
Low refrigerant charge
Add some refrigerant and restart
unit. If cycle time improves, look
for leak.
Hot gas valve leaks through
during freeze
Check hot gas valve for hot outlet
during freeze
Thermostatic expansion valve
bulb loose
Check bulb
Thermostatic expansion valve
producing very low or very high
superheat
Check evaporator superheat,
change TXV if incorrect
Compressor inefficient
Check compressor amp draw, if
low and all else is correct, change
compressor
Debris in refrigeration system
Recover charge. Open quick
connects, check for loose or
missing foil. Open liquid line and
hot gas valves. Check for debris.
Replace drier, evacuate and
weigh in nameplate charge.
Shut down on maximum
harvest time
Ice bridge thickness too small, not
enough ice to open curtain
Check and adjust if needed
Ice bridge thickness too large, ice
frozen to evaporator frame
Check and adjust if needed
Purge valve does not open, water
melts ice bridge, not enough ice to
open curtain
Check purge valve
Incomplete ice formation
Check water distributor for
partially plugged holes
Curtain out of position
Check curtain for swing restriction
November 2010
Page 20
C2648 Service Manual
Problem
Likely Cause
Probable Solution
Diagnostics - Remote Air Cooled
