Lennox LICH4012021T431E-1, Service Manual

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Electrical Control Function
Electrical Control System
113
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 Control
：
Conditions for defrosting:
----
the unit enters the defrosting mode according to the value of T3 and T4 as well as the compressor
running time.
Defrost Stop Conditions:
If any one of the following conditions is satisfied, defrosting ends and the unit returns to heating mode.
----
T3 rises above than TCDE1 ℃ .
----
T3 remains at TCDE2
℃
or above for 80 seconds.
----
The machine runs for 10 consecutive minutes in defrosting mode.
1.3.3.4 High Evaporator Coil Temperature T2 Protection:
TEstop
T2
Resume
Off
Decrease
TEdown
TEnorm
Hold
Off: Compressor stops.
Decrease: Decreases the running frequency.
Hold: Maintains the current frequency.
Resume: No limitation is applied to frequency.
.
1.3.4 Auto-mode
You can choose this mode with the remote control and adjust to temperature to between 17-30.
In auto mode, the machine chooses cooling, heating or fan-only mode according to ΔT (ΔT =T1-Ts).
ΔT=T1-Ts
Running mode
ΔT ＞
2
℃
Cooling
-2<
ΔT≤2
℃
Fan-only
ΔT≤-2
℃
Heating