Input Current Control; Freeze-Up Protection Control - Daikin CTXU25G2V1B Service Manual

Control Specification
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
2. In case the operation mode is heating
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
45
2 Hz drooping
1.0 second after
rushing in the
drooping zone
1 1
Input current
1 2 drooping
1 3
The current droops when outdoor air temperature becomes higher than a certain level
(model by model).
The current droops when outdoor air temperature becomes higher than a certain level
(model by model).
(Reference)
13°C
Reset zone
9.5°C
Up zone
7.5°C
Keep zone
5.5°C
Drooping zone
0°C
Stop zone
After 2.5 seconds
Compressor stops
Stop zone
Drooping zone
Keep
zone
Reset zone
Heat exchanger
thermistor temperature
SiBE12-908
Return from stop
(R4561)
Function and Control