Electrolux EXH09HL1W Service Manual page 51

After replacing outdoor controller, the malfunction still exists:
In that case, check if communication wire, temp sensor, fan, compressor or 4-way valve is normal.
Communication wire: Check if communication wire, live wire and neutral wire are incorrectly connected, or wiring terminal is
poorly connected. If the communication wire is prolonged, check if the joint is well connected.
Temperature sensor: measure resistances to ground of the 3.3V(detection point 6) and IPM15V(detection point 3). If there is
short circuit to ground, check if each temp sensor is damaged.
Electric reactor: If communication malfunction still occurs after replacing electric box, unplug 2 wiring terminals of electric
reactor and measure resistance between these two terminals by universal meter.
Fan: unplug wiring terminal of fan and measure resistance between any two wire among red, yellow, white wire by universal
meter. Usually, the resistance will be hundreds of ohm, otherwise, there is open circuit and the fan is damaged.
Compressor: If operation environment is good, wiring is correct and system is in normal conditions, the H5 protection still
frequently occurs after replacing controller, probably because compressor has malfunction.
4-way valve: unplug two purple wire of 4-way valve and then measure if resistance between these two wire is 1~2K. If the
resistance is too large, there is open circuit of electromagnetic valve and coil of 4-way valve shall be replaced.
If malfunctions above don't exist, inspect indoor unit.
(21) Cautions
1. Before replacing mainboard of inverter outdoor unit, check if the substituted mainboard is qualified. The following tests shall
be done:
a. Check if there is short circuit between any two pins of IGBT. If so, this mainboard of outdoor unit can't be used.
b. Check if there is short circuit between P,N of DC bus bar. If so, this mainboard of outdoor unit can't be used.
c. Check if there is short circuit between P and U,V,W and between N and U,V,W. If there is any short circuit, this mainboard
can't be used.
2. Each kind of compressor is applicable to one kind of mainboard. There is one-to-one relationship between mainboard and
compressor. Before replacement, check the model of the mainboard which has malfunction and then use the mainboard with
the same model for replacement. Don't judge model of mainboard according to model of the unit, or else, mismatching between
mainboard and compressor may be incurred.
3. Before replacing compressor, chosen compressor which has the same model for replacement. Don't judge model of
compressor according to model of the unit, or else, mismatching between compressor and pipeline or controller may be
incurred.
4. Wire can't contact each other, 4-way valve, compressor and sharp edge. Ground wire of compressor, fan and electric box
shall be separately fixed.
210-10 ADL 51/62 599 75 60-77