Hitachi RAC-25NX2 Service Manual page 20

INFORMATION
CAPABILITIES
Heating Capability
• This room air conditioner utilizes a heat pump system that absorbs
exterior heat and brings it into a room to be heated. As the ambient
temperature gets lower, heating capability will also lower. In such a
situation, the PAM and inverter work to increase compressor rpm to keep
the unit's heating capability from decreasing. If the unit's heating
performance is still unsatisfactory, other heating appliances should be
used to augment this unit's performance.
• The air conditioner is designed to heat an entire room so that it may take some time before you feel warm. Timer
operation is recommended for effective preheating ahead of the desired time.
Cooling and Dehumidifying Capabilities
• If the heat present in a room exceeds the unit's cooling capacity (for example, if there are many people in the room
or other heating appliances are used), the preset room temperature may not be reached.
VARIOUS FUNCTIONS
• When fan speed, room temperature are set with the remote controller before starting manual operation and
the buttons are released, the indication of settings will go off in 10 seconds and only the operation mode will
be displayed.
• Pressing the button while the unit is in operation will let the protective circuit work so that the unit will
not operate for approximately 3 minutes.
• During heating operation, the indoor unit's color indicator lamp may flash with no air emitted for a while.
• If you feel cold wind during warming operation with the
quieter after the room is heated, use of (AUTO) setting is recommended.
• With the (SILENT) setting, the unit's cooling capability will lower slightly.
TIMER PROGRAMMING/SLEEP TIMER OPERATION
• When the timer has been programmed, the unit will not operate even if the set time is reached unless the unit
receives a signal from the remote controller. Confirm that timer programming is complete (beep) and the
TIMER lamp of the indoor unit lights.
• If the (SLEEP) button is pressed while the ON/OFF timer is programmed, the sleep timer takes priority.
• During sleep timer operation, the fan speed sets to
controller display indication will remain unchanged even with the
CAUTION
Do not use a stove
or any other high-
temperature devices
in proximity to the
PROHIBITION
indoor unit.
(HI) fan speed or want to make the unit operation
(SILENT) regardless of the preset speed. The remote
(SILENT) setting.
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REGULAR INSPECTION
PLEASE CHECK THE FOLLOWING POINTS EVERY EITHER HALF YEARLY OR YEARLY. CONTACT YOUR
SALES AGENT SHOULD YOU NEED ANY HELP.
Check to see if the unit's earth line has been connected
correctly.
1
If the earth line is disconnected or faulty, unit failure or electric
WARNING
shock hazard may result.
Check to see if the mounting frame has rusted excessively
2
or if the outdoor unit has tilted or become unstable.
WARNING
It could collapse or fall, causing injury.
AFTER SALES SERVICE AND WARRANTY
WHEN ASKING FOR SERVICE, CHECK THE FOLLOWING
CONDITION
If the remote controller is not
• Do the batteries need replacement?
transmitting a signal.
• Is the polarity of the inserted batteries correct?
(Remote controller display is
dim or blank.)
• Is the fuse all right?
• Is the voltage extremely high or low?
When it does not operate.
• Is the circuit breaker "ON"?
• Is the setting of operation mode different from other indoor units?
• Is the air filter blocked with dust?
• Is the set temperature suitable?
• Have the top and bottom air deflectors been adjusted to their correct
When it does not cool well.
When it does not heat well. positions according to the operation mode selected?
• Are the air inlets or air outlets of indoor and outdoor units blocked?
• Is the fan speed "LOW" or "SILENT"?
■ The following phenomena do not indicate unit failure.
<Operation start>
The unit is preparing to blow warm air. Please wait.
During heating, the operation indicator
blinks and air blow stops <In operation>
The outdoor unit is defrosting. Please wait.
Refrigerant flow noise in the pipe or valve sound generated when flow rate is
Hissing or fizzy sounds
adjusted.
Noise generated when the unit expands or contracts due to temperature
Squeaking noise
changes.
Noise generated with the indoor unit fan's rpm changing such as operation start
Rustling noise
times.
Clicking noise Noise of the motorized valve when the unit is switched on.
Noise of the ventilation fan sucking in air present in the drain hose and blowing out
Perking noise dehumidifying water that had accumulated in the condensed water collector. For
details, consult your sales agent.
Operation noise changes due to power variations according to room temperature
Changing operation noise
changes.
Mist emission Mist is generated as the air within the room is suddenly cooled by conditioned air.
CHECK THE FOLLOWING POINTS
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