Mitsubishi SRK19CNS-S, Technical Manual

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'14•SRK-T-164
'09•SRK-SM-087D
(8) Checking the indoor electrical equipment
(a) Indoor PCB check procedure
(b) Outdoor unit
Is there voltage between terminal
blocks
①
and
②
? (AC 220V)
Indoor electrical components
are normal.
Is the voltage between terminal
blocks ② and ③ oscillating between
DC 0 and 20V?
Inspect
If the package components
are not damaged, replace the
fuse and perform an operation
check again.
Compressor stop.
power source
for outdoor unit.
Replace indoor PCB.
Is the fuse burnt out? (3.15 A)
NO
YES
YES
NO
YES
NO
(b) Indoor unit fan motor check procedure
(i) Indoor PCB output check
① ④ ⑤
(ii) Fan motor resistance check
⑥ ⑤ ④ ③ ② ①
⑥ ⑤ ④ ③ ② ①
FM
I
DC15V
Indoor PCB
DC 308~336V
DC several V
(4~6 V)
CNU
(–)
GND
Blue Yellow White Black Re
d
Sensor
Operation
mode
Phenomenon
Shortcircuit Disconnected wire
Heat exchanger
sensor
Cooling
Ourdoor air
temperature sensor
Cooling
Discharge pipe
sensor
All modes
Measuring point Resistance when normal
① − ③ −
④ − ③ −
Measuring
point Resistance when
normal
① − ③
④ −
⑤ −
③
k
1)
2)
3)
③
several V (4 ~ 6V)
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(9) How to make sure of wireless remote control
(C) Power transistor inspection procedure
[Use a tester with a needle indicator for the inspection. (Do not use a digital tester. Check in the AC 300 volt range.)]
(1) If there is a self-diagnosis display, inspect the compressor system (burns, wiring mistakes, etc.) If no problems are found, check the
output of the power transistor.
(2) Output inspection procedure
Disconnect the terminals for the compresseor.
If an output such as the one shown in the figure on the below can be measured, the power transistor and the circuit board for the
outdoor unit are normal.
(Example)
RUN light : ON
TIMER light: 2 time flash
Measure in this section Operation SW ON
8~10 sec. 1 sec. 1 sec. 3 min. 3 min. 1 sec.
0
Output voltage
(ACV)
The figare below shows the SRK series.
of
indoor unit
Replace the display
of indoor unit.
reset (ACL) button