Check Of Lev; Check Of Inverter/Compressor - Mitsubishi Electric MSH09TW Service Manual

•When cooling, heat exchanger of non-operating unit frosts.
•When heating, non-operating indoor unit get warm. (LED display: 0 0 0 0 , p p 1 1 )
L L Check of LEV
Start
Turn on power supply to the outdoor unit after checking LEV coil is mounted to the LEV body securely.
Is "click - click" sound heard?
Or, do you feel vibration of the LEV coil with a hand?
No
Disconnect the connector (CN791: unit A, CN792: unit B, CN793: unit C),
and measure the resistance of LEV coil to check the integrity.
No
Replace the LEV coil.
•When cooling, room does not get cool.
•When heating, room does not get warm. (LED display: 0 0 0 0 , a a 8 8 )
M M Check of inverter/compressor
Start
Disconnect the lead wire to the compressor at terminals.
power suppy, start EMERGENCY OPERATION.
Measure the voltage between
each leading to the compressor.
U (BLK) - V (WHT)
V (WHT) - W (RED)
W (RED) - U (BLK)
Output voltage
COOL: 100V(58Hz) HEAT: 100V(58Hz)
Is voltage output? W1
Yes
No
Is output balanced?
Yes
Turn off power supply of indoor and outdoor unit,
and measure the compressor winding resistance
between the compressor terminals.
Is there resistance of 0.53" to 0.66" between
the each terminals?
Yes
Return the lead wire of compressor to former, and
turn on power supply to indoor and outdoor unit.
Three minutes later, start EMERGENCY OPERATION.
Clarify the causes by counting time until the inverter stops.
0 to 10 seconds: compressor layer short
10 to 60 seconds: compressor lock
60 seconds to 5minutes: refrigerant circuit defective
5 minutes or more: normal
(MXZ30TN MXZ30TN2)
(MXZ30TN MXZ30TN2)
W1 • After the outdoor fan starts running, wait for 1 minutes or more before
measuring the voltage.
• The output voltage values in the above table have the tolerance of i20%.
No LED indicator the inverter
stops due to over current?
Replace the electronic
control P. C. board
with the I.P.M P. C. board.
No
Yes
Normal
Yes
3 minutes after turning on the
1. Turn off power supply of the indoor
No
Yes
2. Turn on power supply to the outdoor
0" Check the resistance
between each terminal
Replace the
compressor.
After 1 minutes has passed since the
power supply of outdoor unit was
turned off, disconnect the connector
CN 553 in the relay P. C. board.
0"
Check the resistance
HPS (63H2).
Replace the
relay P. C. board.
91
Replace the electronic
control P. C. board
and outdoor unit, and disconnect
the connector CN 551 in the relay
P. C. board
unit, and after 1 minutes or more
passed, check the resistance
between the connector
CN551 pin 1 and pin 2.
Infinity
Infinity
Replace the
HPS (63H2).