Hitachi RAS-50YH4 Service Manual page 85

OTHERS
Q15
The indoor fan varies among
high air flow, low air flow and
breeze in the auto fan speed
mode. (Heating operation)
Q16
Loud noise from the outdoor unit is
heard when operation is started.
Q17
Noise from the outdoor unit
occasionally changes.
Q18
There is a difference between the set
temperature and room temperature.
Q19
Air does not flow immediately
after operation is started.
A15
This is because the cool
wind prevention function
is operating, and does
not indicate a fault.
When operation is started, the compressor
A16
rotation speed goes to maximum to increase the
heating or cooling capability, so noise becomes
slightly louder. This does not indicate a fault.
A17 The compressor rotation speed changes according to
the difference between the thermostat set temperature
and room temperature. This does not indicate a fault.
A18
There may be a difference between the set
temperature and room temperature because of
construction of room, air current, etc. Set the
temperature at a comfortable for the space.
A19
Preliminary operation is performed for one
minute when the power switch on and heating
or dehumidifying is set. The operation lamp
blinks during this time for heating. This does
not indicate a fault.
– 95 –
The heat exchanger temperature
is sensed in the auto speed mode.
When the temperature is low, the
fan speed varies among high air
flow, low air flow and breeze.