136
Check of open phase
G
Be sure to use the analog tester for measurement.
• With the lead wire disconnected, activate the inverter and check the balance of voltage between terminals.
MXZ-18RV
MXZ-32RV
<Operation method>
Perform the test run in the heating mode by using the emergency run
switch on the indoor unit.
<Measure point>
Measure the AC voltages at the following three points on the transistor
module
• BLK - WHT
• BLK - RED
• WHT - RED
<Judgment>
Balanced : Normal
Unbalanced : Faulty (Open phase)
Shut off by overcurrent : Faulty (Short)
NOTE 1 : After the outdoor fan starts running, wait for one minute or more before measuring the voltages.
NOTE 2 : The output voltage values in the above table have the tolerance of ± 20%.
• Disconnect the lead wires and check the resistance of terminals at the transistor module.
<Measure points>
Measure the AC voltage at the following six points on the transistor module.
BLK - WHT, WHT - BLK
BLK - RED, RED - BLK
WHT - RED, RED - WHT
<Judgment>
Infinite (
Ω
) : Normal
Zero to dozens (
Ω
) : Faulty (Short)
Operation mode
Operational frequency (Hz)
Output voltage (V)
COOL
58
110
HEAT
58
70
ACV
300
BLK-WHT
ACV
300
BLK-RED
ACV
300
WHT-RED
ACV
300
BLK-WHT
ACV
300
BLK-RED
ACV
300
WHT-RED
Tester indication
Faulty
(unbalanced)
Normal
(balanced)
X1
X1
Normal
(Infinite)
Faulty
(Zero to dozens of ohms)
Tester indication
Check of resistance (transistor module)
H
0
'
Infinite
Start
Unbalanced
G
Check the resistance of
the transistor module.
Balanced
Disconnect the
compressor lead wire.
Replace the transistor
module and outdoor
controll P.C. board in a set.
Replace the outdoor
controll P.C. board.
H
Check of compressor
F
Check of open phase
Simple check methods for inverter/ compressor
F
<MXZ-18/32RV>
<MXZ-18/32RV>
<MXZ-18/32RV>
Operation mode
Operational frequency (Hz)
Output voltage (V)
COOL
58
110
HEAT
40
70
