Daikin FTXA20A Service Manual page 160

3 | Third party components
Service manual
160
2 The superheated degree of suction gas lowers (or the wet operation is
performed). Consequently, the compressor consumes more power and is
noisy (before over‑current relay trips).
3 The subcooling degree of refriferant in liquid form rises (values >4~5K are NOT
normal).
Cooling
High pressure drooping control
High pressure gradually rises with
increasing operating frequency.
High
pressure
(Low pressure is maintained
Low
at a certain level.)
pressure
Operating
frequency
To maintain low pressure, operating
frequency increases on the capacity control.
(Degree of overcharge)
Proper amount
Heating
(High pressure is
High
maintained at a
pressure
constant level.)
Low
pressure
Low pressure rises
due to decreased
frequency.
Frequency
To maintain high pressure, frequency
decreases under the capacity control.
(Degree of overcharge)
Proper amount
Refrigerant shortage diagnosis
1 The superheated degree of suction gas rises. Consequently, the compressor
discharge gas temperature becomes higher than normal.
2 The superheated degree of suction gas rises. Consequently, the electronic
expansion valve turns open more than normal or completely open for average
output.
3 Low pressure drops to cause the unit not to reach cooling capacity (or heating
capacity).
Operating frequency comes to
the lowest level.
Subcooling degree becomes
higher. (The temperature of
liquid connection piping
becomes lower.)
Low pressure rises with lowering
compressor output.
Further overcharge
The electronic expansion valve
is closed due to the overload control.
Frequency comes to
the minimum level.
High pressure drops or rises
immediately after the
overload control is complete.
Low pressure drops due to
closed outdoor unit
electronic expansion valve.
Higher degree of
overcharge
FTXA20~50A(W)(S)(T) + FTXA20~50B(B)(S)(T) + RXA42+50A +
RXA20~35A(9) + RXA42+50B
Split Stylish R32
ESIE18-03D – 2021.05