Mitsubishi Electric SUZ-KA09NA2 Service Manual page 20

D Check of compressor winding
● Disconnect the connector between the compressor and intelligent power module, and measure the resistance between the
compressor terminals.
<Measurement point>
Measure the resistance between the lead wires at 3 points.
BK - WH
BK - RD
WH - RD
<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
Confirm that 1~4 is normal.
• Electrical circuit check
1. Contact of the compressor connector
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?
No
After the compressor is heated with a drier,
does the compressor start?*
Yes
Compressor start failure. Activate pre-heat control.
(Refer to "9-2. PRE-HEAT CONTROL SETTING")
OCH699A
Yes
No
1
<Judgement>
0 second
1 second
2 seconds
10 seconds
10 minutes
Check the refrigerant circuit.
Check the stop valve.
Replace the compressor.
20
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
WARNING:
When opening or closing the valve
below freezing temperatures,
refrigerant may spurt out from the
gap between the valve stem and
the valve body, resulting in injuries.
*1
Heat the compressor with
a drier for about 20 minutes.
Do not recover refrigerant
gas while heating.
Heating part