Mitsubishi MUY-A15NA, Руководство по обслуживанию

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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 EMERGENCY
OPERATION switch on the indoor unit.
(TEST RUN OPERATION : Refer to 7-7.)
<<Measurement>>
Measure the time from the start of outdoor fan running to the stop of
compressor due to over current.
<<Judgement>>
For reference
0~10 seconds·····················Abnormal (compressor short or poor contact)
(compressor lock-out)
10 seconds~5 minutes·······Abnormal (refrigerant circuit defect)
more than 5 minutes···········Normal
Outdoor fan starts
Abnormal
(Compressor winding short or layer short)
(Compressor connector poor contact)
(Compressor lock-out)
Abnormal
(Refrigerant circuit defect, etc.)
Normal
0 second
10 seconds
5 minutes
Check of compressor operation time
F
MUZ-A09/12/15/17 MUY-A15/17
MUZ-A09/12/15/17 MUY-A15/17
Check of outdoor thermistors
G
When OPERATION INDICATOR lamp flashes 6-time.
The thermistors in the outdoor unit are abnormal.
Measure the
resistance
between CN641
1 and 2 .
Measure the
resistance
between CN642
1 and 2 .
No
Yes
Replace the
thermistor
except RT64.
In case that
RT64 is
abnormal,
replace the
inverter P.C.
board, since
RT64 is
combined with
the inverter P.C.
board.
Replace the inverter
P.C. board.
Disconnect the connectors CN641, CN642 and CN643 from the inverter P.C. board.
(Check the characteristics of each thermistor.)
Measure the
resistance
between CN641
3 and 4 .
Reconnect the
connectors
CN641, CN642
and CN643.
Turn ON the
power supply and
press
EMERGENCY
OPERATION
switch.
Discharge
temperature
thermistor RT62
Fin temperature
thermistor RT64
Is the resistance of
thermistor normal?
(Refer to 10-6.1.)
No
Yes
Does the unit operate
10 minutes or more?
OK.
(Cause is poor
contact.)
Measure the
resistance
between CN643
1 and 2 .
Ambient
temperature
thermistor RT65
Defrost thermistor RT61
OB451--2.qxp 06.3.29 9:49 AM Page 44