Mitsubishi Electric PUZ-WM50VHA Service Manual page 33

Phenomena
7. A large amount of water is drained
from the outdoor unit.
8. Compressor does not work after the
breaker switched on.
Phenomena
A flowing water sound or occasional hissing sound is heard.
Water does not heat or cool well.
Water is dripping or vapour is emitted from the outdoor unit.
When restarting the outdoor unit soon after stopping it, it
does not operate even though the ON/OFF button is pressed.
FTC operates without the ON/OFF button being pressed.
"PLEASE WAIT" appears in the remote controller display.
A check code appears in the remote controller display.
• If the unit cannot be operated properly after test run, refer to the following table to find the cause.
Symptom
Wired remote controller
PLEASE WAIT
PLEASE WAIT → Check code
Display messages do not
appear even when operation
switch is turned ON (operation
lamp does not light up).
Note: Operation is not possible for about 30 seconds after cancellation of function selection. (Correct operation)
For description of each LED (LED1, 2, 3) provided on the FTC, refer to the following table.
LED1 (power for microprocessor)
LED2 (power for remote controller)
LED3 (communication between FTC and outdoor units)
OCH727
Factor
1 W ater is drained from PRV because of the
pressure rise in water circuit.
2 W ater leakage due to the breakdown of PRV
Normal operation
(For protection of compressor)
■ These sounds can be heard when refrigerant and/or water is (are) flowing in the in-
door unit or refrigerant pipe, or when the refrigerant and/or water is (are) chugging.
■ Clean the filter of water piping. (Flow is reduced when the filter is dirty or clogged.)
■ Check the temperature adjustment and adjust the set temperature.
■ Make sure that there is plenty of space around the outdoor unit.
■ During cooling mode, water may form and drip from the cool pipes and joints.
■ During heating mode, water may form and drip from the heat exchanger of
outdoor unit.
■ During defrosting mode, water on the heat exchanger of outdoor unit evapo-
rates and water vapour may be emitted.
■ Wait approximately 3 minutes. (Operation has stopped to protect the out-
door unit.)
■ Is the on timer set?
Press the ON/OFF button to stop operation.
■ Is the FTC connected to a external signal?
Consult the concerned people who control the FTC.
■ Does "
Consult the concerned people who control the FTC.
■ Has the auto recovery feature from power failures been set?
Press the ON/OFF button to stop operation.
■ The initial settings are being performed. Wait approximately 3 minutes.
■ If the remote controller is not only for FTC, change it.
■ The protection devices have operated to protect the FTC and outdoor unit.
■ Do not attempt to repair this equipment by yourself.
Turn off the power switch immediately and consult your dealer. Be sure to
provide the dealer with the model name and information that appeared in the
remote controller display.
For about 2
• For about 2 minutes following power-on, operation of the remote controller
minutes after
is not possible due to system startup. (Correct operation)
power-on
• Connector for the outdoor unit's protection device is not connected.
• Reverse or open phase wiring for the outdoor unit's power terminal block (L1, L2, L3)
Subsequent to
about 2 minutes
after power-on
• Incorrect wiring between FTC and outdoor (incorrect polarity of S1, S2, S3)
• Remote controller wire short
Indicates whether control power is supplied. Make sure that this LED is always lit.
Indicates whether power is supplied to the remote controller.
This LED lights only in the case of the FTC which is connected to the outdoor unit
refrigerant addresses "0".
Indicates state of communication between the FTC and outdoor units.
Make sure that this LED is always blinking.
33
1 Check the below items following the indoor unit
manual to suppress the pressure rise in water
circuit.
(1) Check the expansion tank.
(2) Follow the trouble shooting when the water
temperature rises abnormally
2 Check the water pressure and flush with manu-
al drainage water of PRV.
Start operating after 12 hours of power-on.
(Refer to the Install manual.)
Countermeasure
" appear in the remote controller display?
Cause
Countermeasure