Lennox LM012CI-100V433 Service Manual page 12

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.
4.1.4.3. IDU time delay: When compressor stops or unit switches off while in heating mode, IDU fan motor keeps
working for 50 seconds.
4.1.4.4. ODU Fan motor control:
1). While unit:
a. To be switched off
b. Under protection.
c. To the set temperature
The compressor stops working, and the fan motor will stop operation after 50s delay.
2). When switch on unit on heating mode, ODU fan motor will start up 3s earlier before compressor starts up.
3). In the process of defrosting, the fan motor will stop operation 39s delay after compressor stopped.
4). defrosting finish, the compressor stops operation, the fan motor will start working simultaneously.
4.1.4.5. 4-way valve control
1). On Cooling/Dry/Fan mode,4-way valve: OFF,
when unit switched on heating mode,4-way valve: ON.
2). When heating mode switched off, or changed from heating to other modes, the 4-way valve will be OFF 2 min
delay after the compressor stops working.
3). The 4-way valve will be OFF 2 min delay while unit stops working caused by any kinds of protection.
4). In the process of defrosting, 4-way valve will be OFF 39s delay after compressor stopped.
5). When defrosting finish, the compressor stops operation, 4-way valve will be ON after 20s delay.
4.1.4.6. Defrost
Note:
t1: The compressor continuous works time.
t2: The compressor accumulated working time.
t3: The tested max value of "IPT-RT" after compressor works for 8 minutes till to current.
△T: The current value of "IPT-RT" while compressor works. (the instantaneous value)
1). When AC unit works matching a), b) and c):
a. t1 ≥ 120 minutes,
b. t2 ≥ 45 minutes,
c. t3 ≥△T + 4℃ .
it triggers to defrosting.
Defrosting start up: Compressor stops working, and re-starts operation after 44s delay;
2). AC unit quit defrosting automatically after 10 minutes operation.
Defrosting end off: Compressor stops working, and re-starts after 25s delay;
4.1.4.7. Cold air prevention:
This function intends to prevent cold air from being discharged when the heating operation starts up
1). IDU fan motor cold air prevention
① .When RT＜24℃:
a. If ITP＞31℃ while compressor works for 5 min, fan motor will work according to preset fan speed.
b. If IPT≤31℃, fan motor stops working while compressor operation within 2min, if IPT≥27℃, fan motor works in
low speed 2 min, then change to preset speed.
② When RT≥24℃:
a. Within 2 min after compressor starts up working, once IPT＞27℃, fan motor will change to preset speed.
b. After compressor starts working 2 min, fan motor changes to preset speed directly.
Air Conditioner Service Manual
12