Basic Troubleshooting - Hitachi HRNM Serie Installations- Und Betriebshandbuch

AUTOMATIC CONTROLS
12
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.
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 Outdoor Heat Exchanger
During defrosting operation, ice on the outdoor 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.
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 or stop.
AUTOMATIC DEFROSTING CYCLE
When the heating operation is stopped by pressing
RUN/STOP switch, frosting on the outdoor 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 louver is fixed
horizontally.
COMPRESSOR HOT START
RAS-8~12 HRNM Series does not operate within 4 hours
after power supply (stopagge code d1-22).
In case of operating within 4 hours, see "Test Run" chapter.
Sound for the indoor unit heat exchanger
During the cooling opertaion, a sound may be heard from the
indoor unit heat exchanger due to water freezing or melting.
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.
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.