Mitsubishi Electric City Multi PEFY-M20VMA-A Technical & Service Manual page 33

[ VII Troubleshooting ]
Valve closure fail-
ure (leaky valve)
Misconnections of
connectors or con-
tact failure
(4) Drain pump
1 Red
2 Purple
3 Black
1. Check if the drain float switch works properly.
2. Check if the drain pump works and drains water properly in cooling operation.
3. If no water drains, confirm that the check code 2502 will not be displayed 10 minutes after the
operation starts.
Note: The drain pump for this model is driven by the internal DC motor of controller board, so it is not
possible to measure the resistance between the terminals.
Normal
Red–Black: Input 13V DC
Purple–Black: Abnormal (check code 2502) if it outputs 0–13 V square wave (5 pulses/rotation), and
the number of rotaion is not normal.
(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
HWE19070
To check the LEV on the indoor unit, check the indoor unit liquid pipe temperature
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.
(A)
(A)
LEV
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.
Perform a visual check for disconnected connectors.
Perform a visual check of lead wire color.
The fan starts to rotate.
(A)
(B)
(B)
(C)
(C)
(A)
Normal
Short
Open
Termistor (TH22)
Moving part
Switch
Magnet
Abnormal
(any position but short)
(any position but open)
- 26 -
Replace the LEV
if the amount of
leakage is great.
Disconnect the
connectors on
the control board
and perform a
continuity test.
GB