TESTING
PAGE 26
ENGLISH
OUTDOOR UNIT TESTING PROCEDURES
Compressor Testing
If the compressor fails to start, the compressor may have an
internal electrical failure, the compressor may be seized me-
chanically, or the Module Control Board (MCB) may be bad.
To test for a bad failed compressor, perform the following test:
1. Disconnect power and allow 10 minutes. Restore
power and call for normal operation. If the compress-
sor starts, the system may have been in a protection
mode that prevented the compressor from running.
If the compressor does not start, continue on with
testing.
2. Disconnect power. Wait 10 minutes for the capacitors
on the MCB to electrically discharge.
3. Unplug the compressor motor windings terminals
from the MCB.
4a-4d. Ohm the windings through each combination of leads
to determine if there is an open winding. If a winding is
open, replace the compressor. If the windings are
good, check each motor winding lead for a short to
ground. If the compressor winding is shorted to
ground, replace the compressor. If the motor checks
out good, continue on with testing.
3
4a
4b
4c
4d
EEV testing
The EEV metering devices are stepper type valves that have
up to 500 potential positional changes. The electrical coil that
is installed on the end of the EEV body rotates a magnetic
eld that opens and closes the valve. If the valve has failed, it
is either stuck in position or the electrical coil has an internal
problem.
To test for an electrical coil problem, perform the following
test:
1. Disconnect power to the outdoor unit.
2. Unplug the suspect EEV coil from the connection plug
at the ECU.
3. Using an ohmmeter, check the ohms of all combina-
tions of windings.
4. Compare measured Ohms against the chart shown
below.
5. Replace the EEV coil if the ohm range is not correct.
6. If the OHM range is correct, yet the EEV does not
click/pulse open or closed when it should, check for a
mechanically stuck EEV.
7. Move the EEV coil to another EEV circuit to see if the
coil will operate the other EEV. If it works, the EEV
valve is stuck and must be replaced.
8. Always reset power when working with EEV valves
to reset any temperature sensor logic that may be
keeping the EEV from being energized during normal
operation. (Freezing etc.)
Blue Violet Yellow Orange Red
Blue 47 Ω 46 Ω 46 Ω 46 Ω
Violet 92 Ω 92 Ω 92 Ω
Yellow 91 Ω 91 Ω
Orange 91 Ω
Red
EEV Stepper Motor Resistance Values
4
3
2
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