Caring For The Machine; Troubleshooting - Mitsubishi Electric PRH-500MYA Operation Manual

Prevent intrusion of heat during air-cooling
• To prevent the intrusion of heat during cooling operation, provide a curtain or a
blind on the window to block out direct sunlight. Also, do not open the entrance
or exit except in cases of dire necessity.

5. Caring for the machine

Always have filter maintenance performed by a service person.
Before care-taking, turn the power supply OFF.
Caution:
• Before you start cleaning, stop operation and turn OFF the power supply.
Remember that the fan is rotating inside at high speed, posing a serious
risk of injury.
• Clean the filter installed in the field once a week (more a dusty place).
How to clean
• Clear dust away lightly or clean it up with a vacuum cleaner. In the case of
severe staining, wash the filter in lukewarm water mixed with dissolved neutral
detergent or water, and then rinse off the detergent completely. After washing,
dry it and fix it back into place.

6. Troubleshooting

Before you call out a repair man, check the following table to see whether there is
a simple solution to your problem.
G Unit does not cool or heat very well.
• Clean the filter. (Dust and debris that collects in the filter will decrease air-
flow.)
• Check the temperature setting and adjust it if necessary.
• Increase the space surrounding the unit.
Is the air intake or air outlet blocked?
• Is a window or door open?
G The unit does not blow air out right away in the heating mode.
• The unit is preparing to deliver warm air.
G The unit stops operating before arriving at the set temperature in the
heating mode.
• Frost forms when the outdoor temperature is low and humidity is high. Wait
for about 10 minutes for the frost to melt.
G There is a "swishing" noise that occurs from the unit when water flows.
• This sound is made when refrigerant inside of the unit is flowing or refilling.
G A ticking noise is heard from inside of the unit.
• This sound is made when internal parts of the unit expand or contract when
the temperature changes.
G An odor is detected in the room.
• This is caused when the unit expels odors that have been absorbed from the
walls, carpets, furniture or clothing.
G A white mist is expelled from the air outlet part.
• This may occur just after the unit is turned on when a high level of humidity is
present in the room.
G Water or moisture is expelled from the unit.
• This occurs to expel water or moisture that may have collected in the pipes
or around piping fixtures.
• This occurs to dispel water from the heat exchanger.
G The indicators of the remote controller do not light up when operated.
• Turn on the power switch. " " will be displayed.
G
indicator is displayed in the remote controller.
• The start and stop or operation mode or set temperature functions of the
remote controller are not available when the
G The start and stop functions are not available just after restarting the
unit.
• Wait about three minutes (operation has stopped to prevent damage to the
air conditioner).
If none of the above apply, turn the main switch off and contact the dealer from whom you bought the air-conditioner, telling him the model name and the nature of the
problem. Do not try to fix the unit yourself.
In any of the following cases, turn off the main power switch and contact your local dealer for service:
• The operation lamp (on the main unit) flashes.
• The switches do not work properly.
• The circuit breaker trips frequently (or the fuse blows frequently).
• Water has accidentally been splashed into the unit.
• Water leaks from the unit.
• Something is accidentally dropped into the air-conditioner.
• An unusual noise is heard during operation.
Carry out ventilation sometimes
•
•
•
Never pour water or flammable sprays onto the air conditioner. Cleaning using
these methods can result in the failure of the air conditioner, electric shock,
or fire.
G Unit does not start immediately.
G The unit started even though the start/stop button was not pushed.
G The unit stopped even though the start/stop button was not pushed.
G "PLEASE WAIT" is displayed in the remote controller.
G An error code is displayed in the remote controller.
G The fan in the unit does not operate.
indicator is lit.
Since the air periodically gets dirty in a room that is kept closed for a long time,
ventilation is sometimes necessary. When gas appliances are used together
with the air conditioner, special precautions must be taken. If the "LOSSNAY"
ventilation unit developed by our company is used, you can perform ventilation
with less waste. For details on this unit, consult with your dealer.
Caution:
Do not dry the filter by exposing it to direct sunlight or warming it using
fire, etc. Doing so can result in the deformation of the filter.
Washing it in hot water (more than 50
Caution:
• Wait until the unit restarts automatically. The compressor may hesitate re-
suming because a three-minute resume prevention circuit is incorporated in
the outdoor unit for protection of the compressor.
• Is the timer on?
Press the start/stop button to stop the unit.
• Was a distant command sent from the remote controller?
Find out if the remote controller was used.
• Is the indicator lit?
Find out if the remote controller was used.
• Is the automatic (cooling/heating) mode selected?
Press the start/stop button to stop the unit.
• Is the timer on?
Press the start/stop button to restart the unit.
• Was a distant command sent from the remote controller?
Find out if the remote controller was used.
• Is the indicator lit?
Find out if the remote controller was used.
• An automatic startup test is being performed (will last for about two minutes).
• A self-diagnostic function is being performed to preserve the air conditioner.
* Do not attempt to make repairs yourself. Turn the main switch off and
contact the dealer from whom you bought the air conditioner. Provide him
or her with the name of the unit and the information displayed in the re-
mote controller.
• Check the over-current relay on the fan motor to determine whether it has
been tripped.
If the over-current relay has been tripped, reset it after eliminating the cause
of the problem (e.g. motor lock).
To reset the over-current relay, open the control box and press the green
claw on bottom-right of the relay until a click is heard. Release the claw and
check that it returns to its original position.
Note that if it is pressed too hard it will not return to its original position.
°
C) can also result in deformation.
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