Airwell SX 12 DCI, Service Manual

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TROUBLESHOOTING
SM YAZ318 1-A.1 GB
12-9
12.4.5 Checking the electrical expansion valve (EEV)
The EEV has two parts, drive and valve.
When Outdoor unit is powered on, EEV shall run and have click and vibration.
For assuring the problem is of the EEV parts, perform the installation test. check (11.6) and if
fails and no other indications in the diagnostics, than the problem is with the EEV (one or
more).
Drive - a step motor; ringed on the valve. Check the drive voltage, should be12VDC.
Valve – if drive is OK (as above) but still the indoor unit perform no conditioning replace the
valve (no need to take out the refrigerant, just pump down and shut off the main valves).
12.4.6 Checking the thermistors
Check Thermistor connections and wiring - Repair if needed.
Check Thermistor resistance – between 0ºC and 40ºC should be between 35K
Ω and 5K Ω .
12.4.7 Checking the communication
Change to Stand-by or Power OFF and re-start - If the fault is still “Active” check Indoor to
Outdoor Communication wiring and grounding connections (should be less than 2.0
Ω ) - Repair
if needed.
If IDU failure – replace IDU controller that does not respond.
If ODU failure – replace ODU.
12.4.8 Checking for electromagnetic interference (EMC problems)
12.4.8.1 EMC troubles to the A/C unit
Locations most susceptible to noise :
1. Locations near broadcast stations where there are strong electromagnetic waves.
2. Locations near amateur radio (short wave) stations.
3. Locations near electronic sewing machines and arc-welding machines.
Trouble :
Either of the following trouble may occur:
1. The unit may stop suddenly during operation.
2. Indicator lamps may flicker
Correction :
The fundamental concept is to make the system less susceptible to noise
(insulate for noise or distance from the noise source):
1. Use shielded wires.
2. Move unit away from the noise source.
12.4.8.2 EMC troubles to near by home appliances
Locations most susceptible to noise :
1. A television or radio is located near the A/C and A/C wiring.
2. The antenna cable for a television or radio is located close to the A/C and A/C wiring.
3. Locations where television and radio signals are weak.
Trouble :
1. Noise appears in the television picture, or the picture is distorted.
2. Static occurs in the radio sound.
Correction
1. Select a separate power source.
2. Keep the A/C and A/C wiring at least 1 meter away from wireless devices and antenna
cables.
3. Change the wireless device's antenna to a high sensitivity antenna.
4. Change the antenna cable to a BS coaxial cable.
5. Use a noise filter (for the wireless device).
6. Use a signal booster.