Friedrich FSHW091, Service And Parts Manual

Page: 36 / 171

36 PB
OPERATION
9-24k Sequence of Operation
3. Special Functions
Defrosting Control
①
Conditions for starting defrosting
the defrosting operation will start.
②
③
T
outdoor pipe temperature
≥ (T
outdoor ambient temperature
– [T ];
④
The continuous running time of defrosting reaches [tmax. defrosting time].
(1 ) Start the machine to enter into heating operation for heating, the compressor is switched on.
(2 ) Defrosting:
1. Cooling mode
Start the machine to enter into cooling operation for cooling, the compressor is switched on.
2. Dehumidifying mode
Same as the cooling mode.
3. Air-supplying mode
The compressor is switched off.
4. Heating mode
a. Defrosting starts: the compressor is shut down, and restarts it after 55-second delay.
b. Defrosting ends: the compressor stops, then starts it after 55-second delay.
2 . The status of 4-way valve control under the heating mode: getting power;
(1 ) 4-way valve power control under heating mode
a. Starts the machine under heating mode, the 4-way valve will get power immediately.
(2 ) 4-way valve power turn-off control under heating mode
(2) Outer Fans Control
Notes:
After remote shutdown, safety stops, and when the machine stops after reaching the temperature point, as well as after the compressor
.
(3) 4-way valve control
(3 ) Defrosting control under heating mode:
4. Control Logic
(1) Compressor Control
Start the compressor after starting cooling, heating, dehumidifying operations, and the outer fans start for 5s; When the machine is
shutdown, in safety stops and when switching to air-supplying mode, the compressor will stop immediately. In all modes: once the
compressor starts up, it will not be allowed to stop until having run for the [tmin. compressor running time]
(Note: including cases of
shutdown when the temperature point is reached; except the cases requiring stopping the compressor such as fault protection, remote
shutdown, mode switching etc.); In all modes: once the compressor stops, it will be allowed be restart after
3-minute delay (Note: The
indoor units have a function of power memory, the machine can be restarted after remote shutdown and powering up again without
delay).
a. Defrosting begins: The power of 4-way valve will be cut after 50s of entering into the defrosting compressor.
b. Defrosting stops: The 4-way valve will get power after 50s of exiting the defrosting compressor.
a. When you should turn off the power or switch to other mode under heating mode, the power of 4-way valve will be cut after 2 minutes
of the compressor stopped.
b. When all kinds of protection stops, the power of 4-way valve will be cut after delaying 4 minutes.
(4) Evaporator frozen-preventing protection function
At the mode of Cooling, dehumidifying:
Evaporator frozen-preventing protection function is allowed to begin after 6 min of starting the compressor.