Greenheck ERCH - Energy Recovery Unit with Packaged DX (468151) - Manual (Page 46)

46
Energy Recovery Unit with Packaged DX
Troubleshooting - General Refrigeration Circuit
Symptom Possible Cause Corrective Action
Compressor starts
but cuts out on high
pressure switch
High pressure
activates at
410 psig for R22,
600 psig for R410a
Refrigerant overcharge . Check pressures, charge by subcooling .
Condenser fan motor defective . Check fan motor .
Condenser coil inlet obstructed or dirty . Check coil and inlet clearances .
Air or non-condensables in system .
Check high side equalized pressure reading
with equivalent outdoor temperature .
Defective high pressure switch . Replace .
Restriction in discharge or liquid line .
Check refrigerant line pressures, check thermal
expansion valves .
Condensing fan relay not pulling in . Replace .
Compressor cuts out
on thermal overload
Low voltage . Check voltage .
Sustained high discharge pressure .
Check running amperage and conditions
described under ‘Low suction pressure’
symptoms .
High suction and discharge pressures .
Check thermal expansion valve setting, check
for air in system .
Defective compressor overload .
If compressor is hot, allow compressor to cool
for two hours . Recheck for open circuit .
Improper refrigerant charge . Check subcooling .
Improperly wired . Review wiring schematics .
Loose wiring . Check all connections and wires .
Defective start relay . Replace relay .
Motor windings damaged . Verify amp draw .
Compressor hums,
but will not start
Improperly wired . Review wiring schematics .
Low line voltage . Check voltage .
Loose wiring . Check all connections .
Defective start or run capacitor .
Check run capacitor for compressor and fan
motor .
Defective relay start . Replace relay .
Motor winding damaged . Verify amp draws .
Internal compressor mechanical damage . Replace .
Always have a completed Pre-Start-Up Checklist, unit Start-Up Checklist, and Optional Accessories Checklist prior to requesting parts or
service information.