Fisher FSMED-74HFPL Technical & Service Manual page 17

Anti-freezing control to indoor evaporator at cooling mode( T: evaporator temp. )
Evaporator
Evaporator
down
9.7 Dehumidifying mode
9.7.1 The 4-way valve is off in dehumidifying mode
9.7.2 Compressor and Indoor Fan actions in dehumidifying mode
NO
1
2
3
Repeat on and off cycle.
9.7.3 Low room temperature protection:
When room temperature decreases to below 10℃, compressor and outdoor fan will
stop(indoor fan is Breeze). Dehumidifying operation will be resumed when room temperature
restores to over 13℃.
9.7.4 At dehumidifying mode, the anti-freezing function of the indoor heat exchanger is the same as
that of cooling mode.
9.7.5 At dehumidifying mode, the action of fans of indoor is the same as that of air-only mode.
9.8 Heating mode
9.8.1 Generally, the 4-way valve is open in heating mode, but it is closed in defrosting mode. 4-way
valve must delay 2 minutes compared with compressor if the compressor changed into
non-heating mode or turned off. 4-way valve doesn't delay in dehumidifying mode.
9.8.2 Generally, the outdoor fan is turned off with the on-off action of compressor in heating mode,
except for the defrosting mode or the end of defrost.
9.8.3 Action of compressor and outdoor fan motor at heating mode: compressor must run for 7
minutes after starting and then judge temperature. Meanwhile other protections are still valid.
Room temp. up
Room temp. down
Condition
Temp.
T> TE6
Temp. up
T< TE6
T> TE5
Temp.
T< TE5
Conditions Indoor Fan
LOW
TA ≥ TS+2
BREEZE
LOW
TS ≤TA<TS+2
BREEZE
LOW
TA < TS
BREEZE
Condition
T> Ts+3
T<Ts+3
T< Ts+2
T>Ts+2
Compressor
Time
On
>5 Minutes Off
On
>5 Minutes Off
Compressor and Outdoor Fan
ON 6minutes
OFF 4minutes
ON 5minutes
OFF 5minutes
ON 4minutes
OFF 6minutes
Compressor
Off
On
On
Off
16
Outdoor fan
On
Off
On
Off
Outdoor fan
Off
On
On
Off