Mitsubishi Electric PUHY-P168, Service Handbook

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[
VIII
Test Run Mode ]
[6] The following symptoms are normal.
Symptoms
Remote controller dis-
play
Cause
The indoor unit does not start
after starting cooling (heating)
operation. "Cooling (heat-
ing)" icon blinks
on the display.
The unit cannot perform a heating (cooling) operation when other in-
door units are performing a cooling (heating) operation.
The auto vane adjusts its posi-
tion by itself. Normal display After an hour of cooling operation with the auto vane in the vertical
position, the vane may automatically move into the horizontal posi-
tion.
Louver blades will automatically move into the horizontal position
while the unit is in the defrost mode, pre-heating stand-by mode, or
when the thermostat triggers unit off.
The fan stops during heating
operation. Defrost The fan remains stopped during defrost operation.
The fan keeps running after
the unit has stopped. Display is off. When the auxiliary heater is turned on, the fan operates for one
minute after stopping to dissipate heat.
The fan speed does not reach
the set speed when operation
switch is turned on. STAND BY The fan operates at extra low speed for 5 minutes after it is turned on
or until the pipe temperature reaches 35°C[95°F], then it operates at
low speed for 2 minutes, and finally it operates at the set speed.
(Pre-heating stand-by)
When the main power is
turned on, the display shown
on the right appears on the in-
door unit remote controller for
5 minutes. "HO" or "PLEASE
WAIT" icons
blink on the dis-
play.
The system is starting up. Wait until the blinking display of "HO" or
"PLEASE WAIT" go off.
Indoor unit and BC controller
make noise during cooling/
heating changeover. Normal display This noise is made when the refrigerant circuit is reversed and is nor-
mal.
Sound of the refrigerant flow is
heard from the indoor unit im-
mediately after starting opera-
tion. Normal display This is caused by the transient instability of the refrigerant flow and
is normal.