Daikin RZQ Series FCQ20EVA Service Manual page 48

Function Details
Parameters
As the bearing resistance limit pressure decreases during slow operation of the compressor, the
lower limit of frequency is restricted.
4.2.12 Suction Pipe Superheat Protection Control (Only in Heating)
In heating operation, controls compressor operating frequency to prevent oil from remaining in the outdoor
unit heat exchanger by the continuous operation of compressor at high superheated degree of the suction
pipe.
Suction SH > 12˚C
Suction SH > 10˚C
OR
&
EV opening degree = 480pls
Lowering upper limit
frequency for 1-step
every 20 seconds
39
RZQ20/24LVA
A Hz 118.5 Hz
B Hz 93 Hz
C MPa 3.22 MPa
D MPa 3.32 MPa
E MPa 3.92 MPa
F MPa 3.18 MPa
G MPa 2.94 MPa
H MPa 3.08 MPa
I MPa 3.92 MPa
[In cooling/heating]
Normal operation
Normal operation
Suction SH < 6˚C
Suction SH < 8˚C
OR Suction SH < 10˚C
&
EV opening degree <
450pls
Suction SH > 12˚C
OR
Suction SH > 10˚C
&
EV opening degree = 480pls
RZQ36/45LVA,
RZQ45/48MYL
62 Hz
62 Hz
3.68 MPa
3.77 MPa
3.92 MPa
3.63 MPa
3.43 MPa
3.58 MPa
3.92 MPa
Hp  3.04MPa
Compressor frequency lower limit
48Hz (RZQ20/24LVA)
61.5Hz (RZQ36/45LVA, RZQ45/48MYL)
Hp  2.84MPa
After 30 seconds
Suction SH < 6˚C
OR
Upper limit frequency = Maximum frequency
&
Suction SH < 8˚C
OR
&
Raising upper limit
frequency for 1-step
every 20 seconds
SiME281501E
Suction SH < 10˚C
EV opening < 450pls
Function and Control