Service Diagnosis - Scotsman CME1856W User Manual

CME1856W

Service Diagnosis

Problem or Symptom
Poor Harvest
Low Capacity
Compressor cycles on and off
Possible Cause
Scale in water system.
Water or Air Temperatures too
cold
Low system charge
Hot gas valve does not open
Water regulating valve does not
maintain enough pressure (in
freeze) or leaks through (in
harvest)
Extreme hot location
Overcharge of refrigerant
Hot gas valve leaks thru, unit off
on refrigeration error
Compressor overheats
November 2001
Page 32
Probable Correction
Clean water system.
Check temps. Unit cannot
operate with water and air
temps below stated limits.
Recover and weigh charge.
Check for power to the coil, if
there is power, replace the hot
gas valve
Replace the water regulating
valve
Relocate the cabinet
Recover, evacuate and weigh in
the nameplate charge
At the end of the freeze cycle,
there should be a definite
difference in temperature
between the inlet and outlet of
the Hot Gas Valve. If not,
replace the hot gas valve
Low on refrigerant, locate leak,
recover refrigerant, repair leak,
replace drier, evacuate and
weigh in the nameplate charge.
TXV superheat too high, check
charge, if charge is OK, replace
TXV
Mechanical fault with
compressor, replace
compressor
Internal relief valve opened,
check for cause of high
discharge pressure