Troubleshooting Guide

8.4.1.6 Inverter module (IPM) malfunction diagnosis and solution.
Malfunction decision
conditions
When the voltage signal that IPM send to compressor drive
chip is abnormal, the display LED will show “P6” and AC will
turn off.
Supposed causes
● Wiring mistake
● IPM malfunction
● Outdoor fan ass’y faulty
● Compressor malfunction
● Outdoor PCB faulty
Trouble shooting:
IPMmoduleprotection
Checkwhetherthevoltagerange
ofP‐NonIPMmoduleisnormal?
DC277‐356Vfor18‐27KBtu/h;
DC277‐410Vfor36K‐48KBtu/h
Yes
Yes
No
Yes
Checkwhethertheinput
powersupplyiscorrect?
208‐230V,1N,60Hz
No No
Regulateittocorrect,then
checkwhetherthesystem
canworknormally?
Checkwhetherthe
powersupplylineis
connectedcorrectlyand
tightly
Yes
Connectitcorrectly
andtightly,checkok
ornot?
No
Checkwhethertheconnecting
linebetweenmainboardand
theIPMmoduleisconnected
tightly
Yes
Connectittightly,
checkokornot?
No
No
No
Connectitwell,check
okornot?
Checkwhethertheconnecting
lineofthecompressoris
connectedcorrectlyortightly
ReplacetheIPMmodule,
checkwhetherthesystemcan
worknormally?
No
No
Replacethemainboard;check
whetherthesystemcanwork
normally?
No
Replacethecompressor,check
whetherthesystemcanwork
normally?
Checkwhetherthelines
inE‐partboxare
connectedtightly
Yes
Connectittightly,
checkokornot?
No
No
Yes
No
Replacethebridgerectifiers
Checkwhetherthebridgerectifiersare
normal?Usethemultimetertomeasure
theresistancebetweeneachtwo
terminals,checkwhetherthereisthe
conditionthatvalueofresistanceis0
Check whether the connecting line of
every reactor is normal? If the line is
broken,theresistanceofthetwoportsis
∞；Check whether the PFC module
broken.
Replacetheconnectinglineor
reactororreplacethePFCmodule
Yes
No
No
Yes
Troubleissolved
Checkiftheoutdoorfan
runsproperlyortheoutdoor
unitventilationisgood.
No
ForACfanmodels, pleaserefer
to9.4 TroubleCriterionOfMain
Parts,checkwhetherthe
resistanceofthefanmotoris
normal.Ifnot,replacethefan
motor.
ForDCfanmodels,referto
thesolutionoffanspeedhas
beenoutofcontrolmalfunction
.Findoutthecauseandhaveit
solved.
Yes
Yes
Yes