TCL Air Conditioner Service Manual
Electronic Controller 
1. Safety Protection
(1)  Time Delay for Safety protection
z 3 minutes delay for compressor ---The compressor is ceased for 3minutes before restarting to 
balance the pressure in the refrigeration cycle in order to protect the compressor. 
z  2 minutes delay for 4-way valve---The 4-way valve will be ceased for 2 minutes late after 
compressor to prevent the refrigerant-gas abnormal noise when the HEATING
 
operation is 
OFF or switch to the other operation mode. 
(2)  Discharge temperature protection 
There is a temperature sensor on top of compressor, when temperature on top of
 
compressor 
exceeded the limit, system control will shut down the compressor and the display board will 
show the error code. 
(3) Lower voltage protection 
When AC  voltage  ≤158V and keep it for 10 seconds, unit will be shut down for protection. 
(4) Over voltage protection 
When AC  voltage  ≥260V, unit will be shut down and recover while AC≤255V. 
(5) Over current protection 
When the current of outdoor unit is overload, controller shut down the unit immediately and show 
error code. 
(6) Compressor abnormity protection 
When compressor start on or in the process of running, if there is no feedback to controller  or 
load of compressor is abnormity, the air conditioner will shut down, and show error code. 
(7)  IPM module protection 
IPM module has high temperature & over current protection itself, if there is signal  feedback to 
IPM, the outdoor unit will shut down, LED on outdoor PCB will show the error code. 
2. “Feel” Mode Operation
(1)  When the “Feel” mode is selected, the operation mode and initial temperature set are 
determined by the initial room temperature at start-up of the operation except to turn off the  air 
conditioner and operates it again. 
(2)  If the mode is change to “Feel” from other mode, the “Feel” mode doesn’t operate until 
compressor stop for more than 3 minutes. 
Mode 
Initial Room Temperature Initial Set Temperature
COOLING 
RT=26℃  23℃ 
DRY 
26℃>RT≥20℃   RT-2℃ 
HEATING for Heat Pump/ 
FAN for Cooling Only 
RT<20℃ 
 - 
z  In the “Feel” mode, when the controller receives the up or down signal of temperature,
 
the set 
temperature can adjust by 1℃  upper or lower. The biggest you can adjust by 2℃ upper or lower. 
3. “COOLING” Mode Operation
(1) Compressor
 frequency control
According to difference room temperature and set temperature (δt = RT-ST), running  frequency of 
compressor is controlled by electronic controller. When room temperature is much higher than set 
temperature, the compressor will start at a high frequency, and as room temperature goes down, the 
compressor running frequency will go down. When room temperature is lower than set temperature,