Trane Mitsubishi Electric TPEFYP006MS140C Technical & Service Manual page 30

[ VIII Troubleshooting ]
Symptom
Valve closure fail- To check the LEV on the indoor unit, check the indoor unit liquid pipe temperature
ure (leaky valve) that appears on the operation monitor on the outdoor unit's multi control board while
operating the indoor unit in question in the FAN mode and the other indoor units in
the cooling mode.
Normally, the LEV is fully closed while the unit is in the FAN mode. If the valve is
leaky, liquid pipe thermistor reading will be lower than normal. If it is significantly
lower than the inlet temperature on the remote controller, valve closure failure is
suspected. If the amount of leakage is insignificant, replacement of LEV is unnec-
essary unless it is causing a problem.
Misconnections of Perform a visual check for disconnected connectors.
connectors or con- Perform a visual check of lead wire color.
tact failure
(4) Drain-up mechanism
Measure the resistance between the terminals with a tester.
(coil temperature 20°C[68°F])
1
3
(5) Drain float switch (CN4F)
Disconnect the connector, and measure the resistance between terminals with a tester.
(A)
1
2
3
4
Position of the moving part
Up
Down
HWE1833B
Checking Criteria
(A) Termistor (TH22)
(A)
LEV
Normal
340
(A) Moving part
(B) Switch
(B)
(C) Magnet
(C)
(A)
Normal
Short (any position but short)
Open (any position but open)
- 23 -
Abnormal
Open or short
Abnormal
Remedy
Replace the LEV
if the amount of
leakage is great.
Disconnect the
connectors on
the control board
and perform a
continuity test.
GB