12-9
TROUBLESHOOTING
SM YAZDCI 1-A.1 GB
Change to Stand-by or Power OFF and re-start - If the fault is still active - replace controller.
12.4.5
aaChecking the Compressor
Check Compressor connections - Repair if needed.
Use a current probe (“Clamp”) to assure that there is an AC current on each phase – no more
than 15A.
In case there is no current, check the resistance between the three poles. Assure the three coil
resistances are almost the same (between 0.8
Ω
to 1.5
Ω
).
Change to Stand-by or Power OFF and re-start - If the fault is still “Active” - replace controller.
12.4.6
Checking the Reverse Valve (RV)
The RV has two parts, Solonoid and valve.
Solonoid - Running in heating mode, check the voltage between two pins of reverse valve
connector, normal voltage is 230VAC. if no power supply to RV, Check RV operation with direct
230VAC power supply, if OK, replace outdoor controller.
Valve - if RV solonoid is OK (as above) but still no heating operation while compressor is On,
replace the valve.
12.4.7
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).
12.4.8
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
.
12.4.9
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.
12.4.10 Checking for electromagnetic interferance (EMC problems)
12.4.10.1
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
