7. FUNCTIONS
7-1. Explanation of Functions
The numerical values such as temperature, frequency, time and current in parentheses are an example
of CMH3172 and the values are different from the other models.
Control/conditions
INITIAL
Breaker is ON.
Power is supplied to the indoor and outdoor unit
control circuits, however the unit remains stopped.
Positioning of the outdoor unit electric expansion
valve is performed.
The ON/OFF operation
button on the remote
controller is pressed.
If automatic operation mode has been selected
with the remote controller, operation begins in
HEAT, SENSOR DRY, or COOL mode
depending on the room temperature and
outdoor temperature at the time operation starts.
Depending on the operational mode, refer to the HEAT, SENSOR DRY, or COOL item.
This applies in the case of automatic
HEAT/COOL operation.
HEAT
Unit operation
Explanation
The ON/OFF operation
button on the remote
controller is pressed.
The unit is forced to stop for 3 minutes after
the power is turned ON, or 3 minutes after the
compressor stops, in order to protect the
compressor.
The frequency is increased at the rate of 1 Hz
every 0.5 seconds.
Operation lamp illuminates.
Indoor fan is stopped to prevent cold air from
being emitted.
Outdoor unit begins operating after
forced-stop is canceled.
This is in order to stabilize the return of oil to the
compressor.
When the frequency reaches Hz,frequency
increases are stopped for a period of seconds.
(Refor to Table 2 "Freguency control".)
If the indoor and outdoor temperatures are high,
the current peak cut-off activates, stopping any
increases in frequency.
The frequency then increases.
The thermostat turns
OFF.
The outdoor unit stops. (It does not stop if the
thermostat for another indoor unit is ON.)
Approximately 30 seconds after the
thermostat turns OFF, the indoor fan is
stopped.
The indoor fan is stopped.
The indoor and outdoor
temperatures are high.
The outdoor unit starts automatically after 3
minutes.
During these 3 minutes, a low-pressure
pressure balance is achieved, allowing the
compressor to start more easily.
In order to protect the compressor, the outdoor
unit will not operate for 3 minutes after the
thermostat turns OFF, even if the room
temperature drops below the desired
temperature.
The room temperature
has reached the desired
temperature.
Operating frequency is stabilized in order to
maintain a comfortable environment.
The indoor temperature and the remote
controller temperature setting are
approximately equal.
Depending on the relationship between the
remote controller temperature setting and the
room temperature, the compressor may stop
temporarily (in other words, the thermostat
may turn OFF).
When the indoor coil temperature rises,
the compressor starts,
the outdoor fan starts,
and the indoor fan changes from "LL"
to the set fan speed.
The amount of heat pump exceeds the amount
of heat radiation from the room.
Therefore, there is no need to further increase
the compressor capacity, and the frequency is
stabilized or lowered.
The frequency is not increased, even if
there is a difference between the room
temperature and the desired temperature.
In some cases, the frequency may be
decreased.
NOTE
45
