Hitachi UTOPIA RASC Series Installation And Operation Manual page 21

AUTOMATIC CONTROLS
6 AUTOMATIC CONTROLS
The system is equipped with the following functions.
THREE MINUTE GUARD
¡
The compressor remains off for at least 3 minutes once it
has stopped. If the system is started within approximately 3
minutes after it has stopped, the RUN indicator is activated.
However, the cooling operation or the heating operation
remains off and does not start until after 3 minutes has
elapsed.
Operation may stop for 6 minutes maximum to protect
compressor.
FROST PREVENTION DURING COOLING OPERATION
¡
When the system is operated in a low temperature room,
the cooling operation may be changed to fan operation for a
while to avoid frost formation on the indoor heat exchanger.
AUTOMATIC RESTART AFTER POWER FAILURE
¡
If the power supply is interrupted for short periods of time
(up to 2 seconds) the Remote Control switch will retain the
settings and the unit will restart when the power is restored.
If Automatic Restart is required after periods of lost power
supply in excess of 2 seconds please contact your distributor
(optional function).
7 BASIC TROUBLESHOOTING

CAUTION:
When water leakage from the indoor unit occurs, stop the
operation and contact your contractor
When you smell or white smoke occurs from the unit, stop
the system and contact your contractor.
THIS IS NOT ABNORMAL
¡
Sound from deforming Part
−
During system starting or stopping, and abrading sound
might be heard. However, this is due to thermal deformation
of plastic parts. It is not abnormal.
Refrigerant Flow Sound
−
While the system is being started or stopping, sound from
the refrigerant flow may be heard.
Smells from Indoor Unit
−
Smell adheres on indoor unit after a long period of time.
Clean the air filter and panels or make a good ventilation.
Steam from RASC Heat Exchanger
−
During defrosting operation, ice on the RASC heat
exchanger is melted, resulting in making steam.
Dew on Air Panel
−
When the cooling operation continues for a long period
of time under high humidity conditions (higher than 27°C
DB/80% R.H.), dew can form on the air panel.
Dew on Cabinet
−
When the cooling operation continues for a long period of
timer (higher than 27°C DB/80% R.H.), dew can form on
the cabinet.
Sound for the indoor unit heat exchanger
−
During cooling operation, a sound may be heard from the
indoor unit heat exchanger due to water freezing or melting.
SLOW AIR CONTROL DURING HEATING OPERATION
¡
When the compressor is stopped while the thermostat is
OFF, or the system is performing the automatic defrosting
operation, the fan speed is set at the slow position.
AUTOMATIC DEFROSTING CYCLE
¡
When the heating operation is stopped by pressing RUN/
STOP switch, frosting on the RASC unit is checked and the
defrosting operation may be performed for the maximum of
10 minutes.
PREVENTION OF OVERLOAD OPERATION
¡
When the outdoor temperature is too high during heating
operation, heating operation is stopped due to activation of
the outdoor thermistor until the temperature becomes low.
HOT START DURING HEATING OPERATION
¡
To prevent cold air discharge, the fan speed is controlled
from the slow position to the set position according to the
discharge air temperature. At this time the lover is fixes
horizontally.
NO OPERATION
¡
Check whether the SET TEMPERATURE is set at the correct
temperature.
NOT COOLING WELL OR HEATING WELL
¡
Check for obstruction of air flow of the outside or inside
−
units.
Check if too much heat source exists in the room.
−
Check if the air filter is clogged with dust.
−
Check to see if the doors or windows are opened or not.
−
Check if the temperature condition is not within the
−
operating range.
ABNORMAL SWING LOUVER'S POSITION
¡
Check if the four louver's position at the air outlet are in
−
same position.
IF TROUBLE STILL REMAINS...
¡
If the trouble still remains even after checking the above
items, contact your service contractor and inform the
following data:
Unit Model Name
−
Content of Trouble
−
Alarm Code no. on Liquid Crystal Display
−

NOTE:
Except for a long period of shutdown, keep the main switch
ON, since the oil heater is energised when the compressor
is stopped.
PMML0140A rev.1 - 07/2009
21