Electronic Controller Introduction; Electronic Controller - Lennox LM012CI-100V433 Service Manual

4. Electronic Controller Introduction

4.1 Electronic controller

RT-------Room Temperature.
IPT------Indoor Pipe (Coil) Temperature.
ST------Indoor Setting Temperature.
OPT--- Outdoor Pipe Temperature.
CRT--- Compensated Room Temperature.
IDU--- Indoor unit
ODU--- Outdoor unit.
Note: When AC finishing installation, because of the air ventilation and the distance of temperature test sensor to
different location of the house, the temperature for IDU PCB control need compensation.
1）. Cooling mode. CRT=RT;
2）. Heating mode. CRT=RT-3℃ ----- Split AC.
4.1.1 Auto mode
5.2.1.1. The set temperature can be adjusted from 16-31℃ (61-88℉) on auto mode, the operation of fan speed and
vane position according to preset.
5.2.1.2. Operation
When unit set to auto mode, it will work on cooling, heating or fan mode totally according to Δt --the temperature
difference between RT and ST shown as table:
4.1.2 Cooling mode
4.1.2.1. Temperature control :16-31℃(61-88℉), and the operation of fan speed and vane position according to preset.
4.1.2.2. Compressor and process control
1). When RT-ST≥1℃ the compressor starts up working, AC operates as customer preset;
2). When:
a. RT-ST≥1℃, the compressor will start up operation once it stops 3 minutes, and unit without any other protection
or failure code.
b. RT-ST≤-1℃, the compressor will stop working while it works for 6 minutes or more continuously.
c. -1℃＜RT-ST＜1℃, the compressor keeps original state.
3). The compressor will also stop working while unit:
a. switched off.
b. under protection.
c. changed to fan mode.
4). Under normal operation, the compressor can be stopped by program until it works for 6 min at least once starts
up.
5). In the process of unit operation, once the compressor ceased, it should be 3 min delay for the next procedure.
4.1.2.3. ODU Fan motor control:
1). While unit:
a. switched off.
b. under protection.
c. to the set temperature.
The compressor stops working, and the fan motor will stop operation after 50s delay.
Air Conditioner Service Manual
Mode
COOLING
FAN
HEATING
Δt=RT-ST
Δt >1℃
-1℃≤Δt≤ 1℃
Δt <-1℃
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