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50
Check voltage to contactor 52C.
Check voltage to terminal block of outdoor unit. Is
there 12V DC to terminal block between - ?
(2) Compressor and outdoor fan do not operate.(Only indoor fan operates.)
MUM30NN MUM30NN2
Is there 230V AC to terminal block between - ?
Press Emergency operation switch.
3-minute time delay works.
Test mode operates for 30 minutes.
Start
Turn on outdoor power supply.
Check Contactor 52C.
If defective replace.
2
1
Yes
No
Yes
No
L1
L2
Check the indoor and outdoor connection.
No
Yes
Check the indoor unit.
Check voltage to terminal block of indoor unit. Is there
12V DC to terminal block between - ?
2
1
(3) Compressor does not operate.(Outdoor fan operates.)
MUM30NN MUM30NN2
Check resistance to over current relay 51C1,
51C2 and 51C3.
Is there continuity at normal temperature?
Start
Measure resistance to contactor 52C.
Is resistance 0
'
(short) or
'
(open).
Replace over current relay 51C1,51C2
or 51C3
No
Yes
Yes
No
Replace compressor.
Yes
No
Check the outdoor unit wiring.
Measure resistance between the terminals at
3 points on compressor.
Is resistance 0
'
(short) or
'
(open).
(see page 47)
Replace contactor 52C.