Input Current Control; Freeze-Up Protection Control - Daikin Super Multi NX FFQ25B8V1B Service Manual

Control Specification
4.5

Input Current Control

Outline An input current is detected by the CT during the compressor is running, and the frequency
upper limit is set from the input current.
In case of heat pump model, this control, which is the upper limit control of the frequency, takes
priority to the lower limit control of four way valve operation compensation.
Detail
Frequency control in each zone
Stop zone
Drooping zone
Keep zone
Reset zone
Limitation of current drooping and stop value according to the outdoor temperature
4.6

Freeze-up Protection Control

Outline During cooling operation, the signals sent from the indoor unit control the operating frequency
limitation and prevent freezing of the indoor heat exchanger. (The signal from the indoor unit is
divided into zones.)
Detail The operating frequency limitation is judged with the indoor heat exchanger temperature 2
seconds after operation starts and 30 seconds after the number of operation room is changed.
118
Input current
After 2.5 seconds in this zone, the compressor is stopped.
The upper limit of the compressor frequency is defined as operation frequency – 2 Hz.
After this, the output frequency is pulled down by 2 Hz every second until it reaches the keep
zone.
The present maximum frequency goes on.
Limit of the frequency is canceled.
The current droops when outdoor temperature becomes higher than a certain level
(depending on the model).
(Reference)
13˚C
Reset zone
7˚C
Up zone
5˚C
Keep zone
3˚C
Drooping zone
0˚C
Stop zone
Compressor Stop
Stop Zone
Drooping Zone
Keep Zone
Reset Zone
(R14355)
Indoor heat exchanger
thermistor temperature
SiBE121021_C
(R14218)
Function and Control