Control Specification
SiBE12-908
45
Function and Control
3.6
Input Current Control
Outline
Detect an input current by the CT during the compressor is running, and set the frequency
upper limit from such input current.
In case of heat pump model, this control is the upper limit control function of the frequency
which takes priority of the lower limit of four way valve activating compensation.
Detail
The frequency control is made within the following zones.
When a “stop current” continues for 2.5 seconds after rushing on the stop zone, the compressor
operation stops.
If a “drooping current” is continues for 1.0 second after rushing on the drooping zone, the
frequency is 2 Hz drooping.
Repeating the above drooping continues until the current rushes on the drooping zone without
change.
In the keep zone, the frequency limit remains.
In the return / reset zone, the frequency limit is cancelled.
Limitation of current drooping and stop value according to the outdoor air temperature
1. In case the operation mode is cooling
The current droops when outdoor air temperature becomes higher than a certain level
(model by model).
2. In case the operation mode is heating
The current droops when outdoor air temperature becomes higher than a certain level
(model by model).
3.7
Freeze-up Protection Control
Outline
During cooling operation, the signals being sent from the indoor unit allow the operating
frequency limitation and then prevent freezing of the indoor heat exchanger. (The signal from
the indoor unit must be divided into the zones as the followings.
Detail
Conditions for Start Controlling
Judge the controlling start with the indoor heat exchanger temperature after 2 seconds from
operation start and after 30 seconds from changing number of operation room.
Control in Each Zone
2 Hz drooping
1.0 second after
rushing in the
drooping zone
After 2.5 seconds
Compressor stops
Stop zone
Drooping zone
Keep
zone
Reset zone
Input current
drooping
1
1
1
2
1
3
(R4561)
13°C
0°C
Reset zone
Up zone
Keep zone
Drooping zone
Stop zone
Return from stop
Heat exchanger
thermistor temperature
(Reference)
9.5°C
7.5°C
5.5°C