Fisher FSFIF-121AE2, Service Manual

Page: 125 / 157

Electrical Control Function
Electrical Control System 121
When the compressor is running, the indoor fan is controlled as below:
Setting fan
speed
Actual fan speed
H （ =H ）
H+(H+=H+G)
M(M=M)
M+(M+=M+Z)
L(L=L)
L+(L+=L+D)
H- （ H-=H-G)
M-(M-=M-Z)
L-(L-=L-D)
T1-Td ℃
L
H
M
If the compressor stops caused by the room temperature rising, the indoor fan will be forced to run 127
seconds with breeze. During this period, the anti-cold-wind is disabled.
Auto fan action in heating mode:
T1-Td
L
(H+-L)*0.4+L
(H+-L)*0.6+L
H+
(H+-L)*0.8+L
(H+-L)*0.6+L
(H+-L)*0.2+L
1.3.3.3 Defrosting mode
：
Condition of defrosting:
If any one of the following items is satisfied, AC will enter the defrosting mode.
After the compressor starts up and keeps running, mark the minimum value of T3 from the 10th minutes to
15th minutes as T30.
1)If the compressor cumulate running time is up to 29 minutes and T3< TCDI1, T3
＋
T30SUBT3ONE
≦
T30.
2)If the compressor cumulate running time is up to 35 minutes and T3< TCDI2, T3 ＋ T30SUBT3TWO ≦ T30.
3)If the compressor cumulate running time is up to 29 minutes and T3< TCDI3 for 3 minutes.
4)If the compressor cumulate running time is up to 120 minutes and T3<-15
℃
.
Condition of ending defrosting:
If any one of the following items is satisfied, the defrosting will finish and the machine will turn to normal
heating mode.
----T3 rises to be higher than TCDE1 ℃ .
----T3 keeps to be higher than TCDE2
℃
for 80 seconds.
----The machine has run for 10 minutes in defrosting mode.