Troubleshooting – Refrigeration Circuit
Symptom Possible Cause
Corrective Action
$PNQSFTTPS
TUBSUTCVU
cuts out
on high
pressure
switch
High pressure
activates at
600 PSIG
Refrigerant overcharge.
$IFDLQSFTTVSFTDIBSHFCZTVCDPPMJOH
$POEFOTFSGBONPUPSEFGFDUJWF
$IFDLGBONPUPS
$POEFOTFSDPJMJOMFUPCTUSVDUFEPSEJSUZ
$IFDLDPJMBOEDMFBSBODFT$MFBODPJMJGOFDFTTBSZ
"JSPSOPODPOEFOTBCMFTJOTZTUFN
$IFDLIJHITJEFFRVBMJ[FEQSFTTVSFTDIFDLUIFSNBM
expansion valves.
Defective high pressure switch.
Replace.
Restriction in discharge or liquid line.
$IFDLSFGSJHFSBOUMJOFQSFTTVSFTDIFDLUIFSNBM
FYQBOTJPOWBMWFTSFQMBDFBOZEFGFDUJWFDPNQPOFOU
$POEFOTJOHGBOSFMBZOPUQVMMJOHJO
Replace.
$PNQSFTTPS
cuts out
on thermal
overload
Low voltage.
$IFDLWPMUBHF
4VTUBJOFEIJHIEJTDIBSHFQSFTTVSF
$IFDLSVOOJOHBNQFSBHFBOEDPOEJUJPOTEFTDSJCFEVOEFS
iMPXTVDUJPOQSFTTVSFwTZNQUPNT
)JHITVDUJPOBOEEJTDIBSHFQSFTTVSFT
$IFDLUIFSNBMFYQBOTJPOWBMWFTFUUJOHDIFDLGPSBJSJO
TZTUFN$IFDLBJSDPOEJUJPOTBOEDGN
Defective compressor overload.
*GDPNQSFTTPSJTIPUBMMPXDPNQSFTTPSUPDPPMGPSUXP
IPVST3FDIFDLGPSPQFODJSDVJU
*NQSPQFSSFGSJHFSBOUDIBSHF
$IFDLTVCDPPMJOH
*NQSPQFSMZXJSFE
Review wiring schematics.
Loose wiring.
$IFDLBMMDPOOFDUJPOT
%FGFDUJWFTUBSUSFMBZ
3FQMBDFSFMBZ
.PUPSXJOEJOHTEBNBHFE
7FSJGZBNQESBX
$PNQSFTTPS
IVNTCVU
will not start
*NQSPQFSMZXJSFE
Review wiring schematics.
Low line voltage.
$IFDLWPMUBHF
Loose wiring.
$IFDLBMMDPOOFDUJPOT
%FGFDUJWFTUBSUSFMBZ
3FQMBDFSFMBZ
.PUPSXJOEJOHEBNBHFE
7FSJGZBNQESBXT3FQMBDFDPNQSFTTPSJGOFDFTTBSZ
*OUFSOBMDPNQSFTTPSNFDIBOJDBM
damage.
Replace.
$PNQSFTTPS
OPJTZPS
WJCSBUJOH
Refrigerant overcharge.
$IFDLQSFTTVSFTBOETVCDPPMJOH
-JRVJEnPPECBDL
$IFDLUIFSNBMFYQBOTJPOWBMWFTFUUJOH$IFDLGPS
refrigerant overcharge.
5VCJOHSBUUMF
%BNQFOUVCJOHWJCSBUJPOCZUBQJOHPSDMBNQJOH$BSFGVMMZ
CFOEUVCJOHBXBZGSPNDPOUBDUXIFSFQPTTJCMF
4DSPMMDPNQSFTTPSSPUBUJOHJOSFWFSTF
QIBTF
$IFDLIJHIBOEMPXTJEFQSFTTVSFTEVSJOHPQFSBUJPOUP
DPOmSN3FXJSFGPSPQQPTJUFSPUBUJPO
Damaged compressor.
Replace the compressor.
*NQSPQFSNPVOUJOHPOVOJUCBTF
$IFDLUIBUDPNQSFTTPSJTQSPQFSMZJTPMBUFEBOENPVOUJOH
CPMUTBSFUJHIU
Always have a completed Pre-Start-Up Checklist and Start-Up Checklist prior to requesting parts or service
information.
23
Packaged Rooftop Ventilator
®