-131-
Disconnect the control board connector and connect
the check LED as shown in the figure below.
When the base power supply is turned on, the indoor LEV
outputs pulse signals for 10 seconds, the outdoor LEV
outputs pulse signals for 17 seconds.
If the LED does not light up, or lights up and remains on,
the driver circuit is abnormal.
If the LEV is locked up, the drive motor turns with no
load and a small clicking sound is generated.
Generation of this sound when the LEV is fully closed
or fully open is abnormal.
Measure the resistance between the coils (red - white, red
- orange, brown - yellow, brown - blue) using a tester. They
are normal if the resistance is within 150
Ω
±
10%.
Measure the resistance between the coils (gray - orange,
gray - red, gray - yellow, gray - black) using a tester. They
are normal if the resistance is within 46
Ω
±
3%.
1
If you are checking the indoor unit’s LEV, operate the
indoor unit’s blower and the other indoor units in the
cooling mode, then check the piping temperatures
(liquid pipe temperatures) of the indoor units by the
operation monitor through the heat source unit’s
control board. When the fan is running, the linear
expansion valve is fully closed, so if there is leakage,
the temperature sensed by the
thermistor (liquid pipe temperature
sensor) will become low. If the
temperature is considerably low
compared to the remote control’s
intake temperature display, it can
be judged that there is a failure
to close fully. In the case of
minimal leakage, it is not necessary to replace the
LEV if there are no other effects.
1
Check for pins not fully inserted on the connector and
check the colors of the lead wires visually.
2
Disconnect the control board’s connector and conduct
a continuity check using a tester.
Judgment methods and likely failure mode
Caution:
The specifications of the outdoor unit (outdoor LEV) and indoor unit (indoor LEV) differ. For this reason, there are
cases where the treatment contents differ, so follow the treatment specified for the appropriate LEV as indicated in
the right column.
Microcomputer
driver circuit
failure
LEV mechanism
is locked.
The LEV motor
coils have a
disconnected
wire or is shorted.
Fully closed
failure (valve
leaks)
Faulty wire
connections in
the connector or
faulty contact.
Failure Mode
Judgment Method
Treatment
Affected LEV
Thermistor
liquid pipe
(tempera-
ture sensor)
Linear
Expansion
Valve
In the case of driver circuit
failure, replace the control
board.
Replace the LEV.
Replace the LEV coils.
Replace the LEV coils.
If there is a large amount of
leakage, replace the LEV.
Check the continuity at the
places where trouble is found.
Indoor
Outdoor
Indoor
Outdoor
Indoor
Outdoor
Indoor
Indoor
Outdoor
Outdoor
Indoor, BC controller
1
1
Содержание 500YEMK-A
Страница 15: ... 12 FANCON board G A board CNFAN CNFC2 CNPOW CNE CNDC1 CN15V1 CNDR1 CNIPM1 ...
Страница 16: ... 13 Y C board SNB board ...
Страница 17: ... 14 RELAY board CNRT2 CNCH CN52C2 CN52F CN51C2 CNOUT2 ...
Страница 19: ... 16 CONT board CNTR SWU2 SWU1 SW3 SW2 CNS1 M NET transmission CNFC1 CN20 Power supply 1 N 3 L1 ...
Страница 20: ... 17 FANCON board CNW CNV CNU CNFC2 ...
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