Mitsubishi Electric SVZ-KP18NA Service Manual page 24

D Check of compressor winding
● Disconnect the connector (CN61) between the compressor and intelligent power module, and measure the resistance be-
tween the compressor terminals.
<<Measurement point>>
at 3 points
BLK - WHT
Measure the resistance between the lead wires at 3 points.
BLK - RED
WHT - RED
<<Judgement>>
Refer to "10-4. TROUBLE CRITERION OF MAIN PARTS".
0[Ω] ·············· Abnormal [short]
Infinite [Ω] ······ Abnormal [open]
NOTE: Be sure to zero the ohmmeter before measurement.
E Check of compressor operation time
●Connect the compressor and activate the inverter. Then measure
the time until the inverter stops due to over current.
<<Operation method>>
Start heating or cooling operation by pressing the TEST button
twice on the remote controller. (Test run mode)
(TEST RUN OPERATION: Refer to 10-5 B.)
<<Measurement>>
Measure the time from the start of compressor to the stop of
compressor due to overcurrent.
F Check of compressor start failure
Confi rm that 1~4 is normal.
• Electrical circuit check
1. Contact of the compressor connector (including CN61)
2. Output voltage of inverter P.C. board and balance of them (See 10-5. )
3. Direct current voltage between DB61(+) and (-) on the inverter P.C. board
4. Voltage between outdoor terminal block S1-S2
Does the compressor run for 10 seconds or
more after it starts?
After the compressor is heated with a drier,
does the compressor start?*
Compressor start failure. Activate pre-heat control.
(Refer to "9-2. PRE-HEAT CONTROL SETTING")
TCH022
Yes
No
1 No
Yes
<<Judgement>>
0 second
1 second
2 seconds
10 seconds
10 minutes
Check the refrigerant circuit.
Check the stop valve.
Replace the compressor.
24
Compressor starts
Abnormal
(IPM failure)
(Compressor winding short)
Abnormal
(Compressor lock out)
(Starting defect)
Abnormal
(Poor contact,)
(Outdoor P.C. board defect)
(Disconnected connector)
Abnormal
(Refrigerant circuit defect)
(Closed valve)
Normal
*1
Heat the compressor with
a drier for about 20 minutes.
Do not recover refrigerant
gas while heating.
Heating part