/05&6OJUJTFRVJQQFEXJUIBQIBTFMPTTQIBTFSFWFSTBMDPOUSPM*GTZTUFNEPFTOPUTUBSUDIFDLQIBTFPGFMFDUSJDBM
TVQQMZ
5IFmSTUTUFQJOUSPVCMFTIPPUJOHBSFGSJHFSBUJPODJSDVJUJTUPFYBNJOFUIF%%$BOEEJHJUBMTDSPMMDPNQSFTTPSDPOUSPMMFS
JGQSFTFOUBOETFFJGUIFSFJTBGBVMUDPEF5IFOFYUTUFQJTUPDIFDLBJSnPXDPOEJUJPOT FHJNQSPQFSEVDUXPSL
BUZQJDBMXFUCVMCESZCVMCFUD"GUFSUIFTFTUFQTIBWFCFFOFMJNJOBUFEQSPDFFEXJUIUSPVCMFTIPPUJOHCZGPMMPXJOH
this guide.
Troubleshooting – Refrigeration Circuit
TROUBLESHOOTING NOTE
#FGPSFBOZDPNQPOFOUTBSFDIBOHFEPOUIF
SFGSJHFSBUJPOTZTUFNUIFDBVTFPGUIFGBJMVSFNVTUCF
JEFOUJGJFE'VSUIFSQSPCMFNTXJMMFYJTUVOMFTTUIFUSVF
DBVTFPSQSPCMFNJTJEFOUJGJFEBOEDPSSFDUFE
IMPORTANT
%POPUSFMFBTFSFGSJHFSBOUUPUIFBUNPTQIFSF*G
required service procedures include the adding or
removing of refrigerant, the service technician must
DPNQMZXJUIBMMGFEFSBMTUBUFBOEMPDBMMBXT5IF
QSPDFEVSFTEJTDVTTFEJOUIJTNBOVBMTIPVMEPOMZCF
QFSGPSNFECZBRVBMJGJFE&1"$FSUJGJFE5FDIOJDJBO
Symptom Possible Cause
Corrective Action
$PNQSFTTPS
will not run
or does not
start
Open disconnect switch or circuit
CSFBLFS
$MPTFTXJUDIBOEPSCSFBLFS
$PNQSFTTPSDPOUBDUPSOPUDMPTJOH
$IFDLWPMUBHFUPDPOUBDUPSDPJMUSBOTGPSNFSTMBWFSFMBZ
TZTUFN3FQMBDFQBSUTBTOFDFTTBSZ
#MPXOGVTFPSUSJQQFECSFBLFS
$IFDLGPSSFBTPOBOESFQBJS3FQMBDFGVTFBGUFSDPSSFDUJOH
QSPCMFN
Low line voltage.
$IFDLMJOFWPMUBHF*GNPSFUIBOGSPNDPNQSFTTPS
NBSLJOHDPSSFDUJOHJTOFDFTTBSZ
$PNQSFTTPSNPUPSQSPUFDUPSPQFO
.PUPSUIFSNBMQSPUFDUPSBVUPNBUJDBMMZSFTFUT"MMPXUJNF
IPVSTGPSDPNQSFTTPSUPDPPMEPXOTPQSPUFDUPSXJMM
SFTFU3FTUBSUBOEDIFDLGPSSFBTPOPWFSIFBUPDDVSSFE
$PNQSFTTPSEFGFDUJWF
$IFDLNPUPSGPSPQFODJSDVJUTIPSUDJSDVJUHSPVOEFE
XJOEJOHTPSCVSOPVU$PNQSFTTPSNBZCFTFJ[FEDIFDL
SFGSJHFSBOU*GOFDFTTBSZSFQMBDFDPNQSFTTPS
)JHIQSFTTVSFTXJUDIPQFO
or defective.
*GNBOVBMSFTFU IJHIQSFTTVSFSFTFUTXJUDI 4XJUDI
PQFOTBUQTJBOEXJMMOPUSFTFUBCPWFQTJGPS
3"3FQMBDFJGEFGFDUJWF
Low pressure switch open
or defective.
4XJUDIXJMMPQFOBUQTJBOEBVUPDMPTFBUQTJ
Replace if defective.
Open room thermostat or control.
/PDPPMJOHSFRVJSFE
$IFDLSPPNUFNQFSBUVSF*GUFNQFSBUVSFJTQSPQFSXBJU
for thermostat to close.
Loose wiring.
$IFDLBMMXJSFUFSNJOBMTBOEUJHIUFOBTOFDFTTBSZ
$PNQSFTTPS
TUBSUTCVU
cuts out on
low pressure
Low pressure
switch
activates at
50 PSIG
Low or loss of refrigerant charge.
$IFDLSFGSJHFSBOUQSFTTVSFTBOEUFNQFSBUVSFT
TVCDPPMJOH
"JSnPXSFTUSJDUFE
$IFDLGPSEJSUZFWBQPSBUPSDPJMEJSUZmMUFSTEBNQFST
DMPTFEJDFEFWBQPSBUPSDPJMJNQSPQFSCFMUDIFDLNPUPS
BNQTDIFDLEVDUEFTJHO
Restriction in refrigerant line.
$IFDLSFGSJHFSBOUQSFTTVSFTMPPLGPSGSPTUFEUVCJOHBOE
DPNQPOFOUTJOEJDBUJOHBSFTUSJDUJPO$IFDLQSFTTVSFESPQ
BDSPTTUIFmMUFSESJFS
Defective low pressure switch.
Replace.
Always have a completed Pre-Start-Up Checklist and Start-Up Checklist prior to requesting parts or service
information.
22
Packaged Rooftop Ventilator
®
