Mitsubishi City Multi PURY-P400 Service Handbook page 91

(9) Treatment of Fan Motor Related Troubles
Condition
1 The fan motor will not run
for 20 minutes or longer
when the AK value is
10%. (When the MAIN
board's SW1 is set as
shown below, the AK
value is displayed by the
service LED.)
SW1 = 1110001000
2 The fan motor vibrates
considerably.
Possible Cause
1) The power supply voltage
is abnormal.
2) Wiring is faulty.
3) The motor is faulty.
4) A fuse (F1, F2, F3) is
defective.
5) The transformer (T01) is
defective.
6) The circuit board is faulty.
Check Method and Treatment
If there is an open phase condition before the breaker, after
the breaker, or at the power supply terminal blocks TB1A or
TB1B, correct the connections.
If the power supply voltage deviates from the specified
range, connect the specified power supply.
For the following wiring, 1) check the connections, 2) check
the contact at the connectors, 3) check the tightening
torque at parts where screws are tightened, 4) check the
wiring polarity, 5) check for a broken wire, and 6) check
grounding.
TB1A~NF~TB1B~CNTR1~T01~CNTR,
TB1B~CNPOW, CNFAN~CN04~CNMF,
CNFAN~52F~CN05~CNMF
CNFC1~CNFC2
* Check if the wiring polarity is as shown on the wiring
diagram.
Measure the resistance of the motor's coils: 20~60Ω
Measure the motor's insulation resistance with a megger:
10 MΩ (DC 500 V) or more
If a fuse is blown, replace it.
Judge that T01 is faulty. Go to "Individual Parts Failure
Judgment Methods."
If none of the items in 1) through 5) is applicable, and the
trouble reappears even after the power is switched on
again, replace the circuit board using the following proce-
dure. (When replacing the circuit board, be sure to connect
the connectors and ground wire securely.)
1 Replace the FANCON board only. If the problem
disappears, there is a problem with the FANCON
board.
2 Replace the FANCON board and the MAIN board. If
the problem disappears, there is a problem with the
MAIN board.
3 If the problem continues even after performing the
procedures 1 and 2 above, then there are problems
with both boards.
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