Input Current Control; Freeze-Up Protection Control - Daikin FTKS20CVMB Service Manual

SiENBE04-401A
3.5

Input Current Control

Detect an input current by the CT during the compressor is running, and set the frequency
Outline
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.
The frequency control will be made within the following zones.
Detail
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 will be 2 Hz drooping.
Repeating the above drooping continues until the current rushes on the drooping zone without
change.
In the unchanged zone, the frequency limit will remain.
In the return / reset zone, the frequency limit will be 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 (only for heat pump model)
3.6

Freeze-up Protection Control

During cooling operation, the signals being sent from the indoor unit allow the operating
Outline
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 sec from
operation start.
Control in Each Zone
Function and Control
2 Hz drooping
1.0 second after
rushing in the
drooping zone
I 1
Input current
drooping
I 2
I 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).
Heat exchanger
thermistor temperature
A
B
C
D
E
After 2.5 seconds
Compressor stops
Stop zone
Drooping zone
Unchanged
zone
Reset zone
Return / Reset zone
Up zone
Unchanged zone
Drooping zone
Stop zone
Control Specification
(R1378)
(R1379)
63