Checking The Indoor Electrical Equipment - Mitsubishi Heavy Industries SRK20ZJX-S Service Manual

(b) Outdoor unit
Operation
Sensor
mode
Cooling
Heat exchanger
sensor
Heating
Cooling
Ourdoor air
temperature sensor
Heating
Discharge pipe
All modes
sensor

(9) Checking the indoor electrical equipment

(a) Indoor PCB check procedure
Is there voltage between terminal
blocks and ? (AC 220/230/240
V)
YES
Is the fuse burnt out? (3.15 A)
YES
Is the voltage between terminal
blocks and oscillating between
DC 0 and 20V?
YES
Indoor electrical components
are normal.
(b) Indoor unit fan motor check procedure
1) Indoor PCB output check
DC several V
(4~6 V)
CNU
2) Fan motor resistance check
Measuring point
Shortcircuit
NO
Inspect power source
for outdoor unit.
NO
Replace fuse.
NO
Replace indoor PCB.
(–)
GND
DC15V
FM
I
Resistance when normal
k
57
-
Phenomenon
Defrosting is performed for 10 minutes at approx. 40 minutes.
Defrosting is performed for 10 minutes at approx. 40 minutes.
DC 308~336V
Indoor PCB
-
'09•SRK-SM-087D
'10 • SCM-SM-094
Disconnected wire
Measuring Resistance when
point normal