Fisher FSAI-Pro-122AE2, Service Manual

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Preheating release condition:
If T4
＞
5
℃
or the compressor starts running, the preheating function will stop.
8.3.8 Sensor protection at open circuit and breaking disconnection.
When there’s one temperature sensor in malfunction, the air conditioner will display error code and will
not stop immediately, to avoid the case that the air conditioner is in urgent need.
Fault temp.
sensor Operation in cooling,
drying and fan only mode Operation in heating mode
T1
Run supposed T1=26
℃
high fan speed
Run supposed T1=26
℃
medium fan speed
T2 Normal During the first 1 minute of compressor operation, indoor
fan shuts off. After that, indoor fan runs at medium fan
speed for 1 minute and then resume to the setting fan
speed.
T3 Run with compressor
frequency
≤
F14
3 minutes’ defrosting every 40 minutes when T4<7
℃
; 2
minutes’ defrosting every 90 minutes when T4≥7
℃
.
T4
Run supposed T4=50
℃
Run supposed T4=15
℃
TP
Run supposed T4=50
℃
Run supposed T4=15
℃
8.3.9 Refrigerant leakage detection
This function is only active in cooling mode. It can better prevent the compressor being damaged
by refrigerant leakage or compressor overload.
Open condition:
Define the evaporator coil temp.T2 of the compressor just starts running as Tcool.
In the beginning 5 minutes after the compressor starts up, if T2
＜
Tcool
－
2
℃
does not keep
continuous 4 seconds and this situation happens 3 times, the display area will show “EC” and AC will
turn off.
8.3.10 Zero crossing detection error protection
If AC detects time interval is not correct for continuous 240s, the unit will stop and the LED will display
the failure. The correct zero crossing signal time interval should be between 6-13ms.