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[8-8 Troubleshooting LEV Problems ]
8-8-2
Possible Problems and Solutions
The specifications of the outdoor unit (outdoor LEV) and the indoor unit (indoor LEV) differ. Therefore, remedies for each fail-
ure may vary. Check the remedy specified for the appropriate LEV as indicated in the below column.
Malfunction
mode
Microcomputer
Disconnect the control board connector and connect the check
driver circuit fail-
LED as shown in the figure below.
ure
Resistance : 0.25W 1kΩ
LED : DC15V 20mA or more
When the main power is turned on, the indoor unit circuit board
outputs pulse signals to the indoor unit LEV for 10 seconds, and
the outdoor unit circuit board outputs pulse signals to the outdoor
unit LEV for 17 seconds.
If any of the LED remains lit or unlit, the drive circuit is faulty.
LEV mechanism
If the LEV is locked, the drive motor runs idle, and makes a small
is locked
clicking sound.
When the valve makes a closing and opening sound, the valve
has a problem.
Disconnected or
Measure the resistance between coils (red-white, red-orange,
short-circuited
brown-yellow, brown-blue) with a tester. When the resistance is
LEV motor coil
in the range of 150Ω ± 10%, the LEV is normal.
Measure the resistance between coils (red-white, red-orange,
red-yellow, red-blue) with a tester. When the resistance is in the
range of 100Ω ± 10%, the LEV is normal.
Measure the resistance between coils (red - white, red - orange,
brown - yellow, brown - blue) with a tester. When the resistance
is in the range of 46Ω ± 3%, the LEV is normal.
Incomple sealing
When checking the refrigerant leak from the indoor LEV, run the
(leak from the
target indoor unit in the fan mode, and the other indoor units in
valve)
the cooling mode. Then, check the liquid temperature (TH2) with
the self-diagnosis LED. When the unit is running in the fan mode,
the LEV is fully closed, and the temperature detected by the
thermistor is not low. If there is a leak, however, the temperature
will be low. If the temperature is extremely low compared with the
inlet temperature displayed on the remote controller, the LEV is
not properly sealed, however, if there is a little leak, it is not nec-
essary to replace the LEV when there are no effects to other
parts.
Faulty wire con-
1.
Check for loose pins on the connector and check the col-
nections in the
ors of the lead wires visually
connector or
2.
Disconnect the control board's connector and conduct a
faulty contact
continuity check using a tester.
28
- chapter 8
Judgment method
6
5
4
3
2
1
1 k
LED
Thermistor
(liquid piping
temperature detection)
Linear Expansion Valve
Remedy
When the drive circuit has
Indoor
a problem, replace the
Outdoor
control board.
Replace the LEV.
Indoor
Outdoor
Replace the LEV coils.
Indoor
Replace the LEV coils.
Outdoor
(LEV2a,
LEV2b)
Replace the LEV coils.
Outdoor
(LEV1, LEV4,
LEV9)
If there is a large amount
Indoor
of leakage, replace the
LEV.
Check the continuity at
Indoor
the points where an error
Outdoor
occurs.
Target LEV
BS_08_M
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Troubleshooting
