Hitachi YUTAKI Series - Fault Diagnosis of DC Fan Motor

223
Checking procedure for main parts
SMGB0066 rev.0 - 12/2009
Troubleshooting
Service Manual
7
IncasethatMg.SW52C(CMC1)isnotON,thecompressorcurrentwilltravelthroughtheseresistances,andtheywillbe
broken. Mg. SW 52C (CMC1) should be checked. Check the resistance between the primary and secondary terminal where
thecontactpointismeltedforMg.SW42C.Ifthereiscontinuity,thecontactismeltedand52Cisbroken(NG).
ReactorresistancecanbemessuredbetweenTB3andRB=0,2Ω.Checkingthiscomponentisnotnecessary.

note
Noise lter does not affect ISPM directly, so is not necessary to check it when ISPM fails. -
Both digital or analog testers are valid to check the values. -
 
About DC fan motor fault diagnosis:
WhenISPM/DIP-IPMisfaultyandAlarm53appears,thefanmotormayalsobedamaged.TopreventISPM/DIP-IPM
damagewhichmayresultfromoperationcombinedwithafaultyfanmotor,checkalsoifthefanmotorisnotdamagedwhen
ISPM/DIP-IPM is replaced

note
Turn OFF main power before start working. -
Working and checking with the power ON may disturb correct diagnosis and may result in failure. -
DC motor(s) included in different models:
 
RHUE-3AVHN 2
RHUE-4AVHN 2
RHUE-5AVHN 2
RHUE-5AHN 2
RHUE-6AVHN 2
RHUE-6AHN 2
 
1. Remove fan motor connectors from the control PCB ISPM or DIP-IPM and turn the fan motor shaft by hand.
 
Faulty:
No continuous rotary torque movement felt when turning the motor
by hand. This occurs because the internal magnet of the fan motor
breaks the movement when the internal electronic circuit of the fan
motor has a short-circuit fault
2. Measure the fan motor resistance using a tester.