Shut Down on
Maximum Freeze Time
(continued)
Compressor not operating
(continued)
Check compressor start
components, check PTCR
resistance and 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
September 2006 Page 53
Problem
Likely Cause
Probable Solution
Diagnostics - Remote Air Cooled
