HAIER CHILLER 
39
11. Control system 
11.1 Electric control function for chille  r P CB  0 0 10 45 29 32
1. Cooling mode: 
Startup: After pressing ON button, the cycling pump works firstly, the 25% solenoid valve will start 1 
minute(revisable) later, 10 seconds later the main and Y contactor of compressor start, 5 seconds(revisable) 
later, Y-△ conversion begins, Y contactor will close and △ contactor will open, 10 seconds later, the 25% 
solenoid valve will be open and start the 50% solenoid valve, the startup is complete, enter energy regulation 
process. 
Energy regulation: when cycling water outlet temp. > setting temp. + download temp. difference, the 
chiller will upload from 25% to 100%, or will keep the original energy. When cycling water outlet temp. <  
setting temp. - download temp. difference, the chiller will download from 100%~25% until stop working. The 
condensed fan started by steps, start of stop the fan by comparing the setting pressure with the detect value, 
the started pressure of fist group fans is P1(can be setted between 1.45-1.75MPa), the started pressure of 
second group fans is P2(can be setted between 1.65-1.95MPa), the started pressure of third group fans is 
P3(can be setted between 1.85-2.15MPa), the pressure difference for each group fan is 0.3MPa. After the 
chiller works for 100%, the chiller will download compulsively to 75% when the discharging pressure is over 
2.25MPa(revisable) until the pressure resume to 2.0MPa(revisable), then upload to 100% again. (Note: once 
the fan starts, run 10 seconds compulsively and then judge if the fan stops by pressure; judge pressure and 
restart fan motor after the fan motor has stopped for 5 seconds) When compressor run in 50% lasts for over 30 
minutes, compressor will unload to 75% compulsively, then upload or download by adjusting temp. condition. 
The chiller will download to 75% compulsively when the discharging pressure is over 2.25MPa(revisable) and 
will not upload to 100% unless the pressure resume to 2.0MPa(revisable).  
Stop the chiller: the current capacity change to 25% operation when stop the chiller, 1 minute later the 
compressor stops, 10 seconds later the fan motors stop in turn, 5 seconds later stop the 25% valve, another 1 
minute(revisable) later stop the water pump.  
2. Heat mode: 
Startup: After pressing ON button, the cycling pump works firstly, the 1# condensing fan motor will start 
and 4-way valve open after 1 minute(revisable), 3 seconds later 2# condensing fan motor start, 3 seconds later 
3# condensing fan motor start, 5 seconds later 25% solenoid valve start, 10 seconds later the main and Y 
contactor of compressor start, 5 seconds(revisable) later, Y-△ conversion begins, Y contactor will close and △ 
contactor will open, 10 seconds later, the 25% solenoid valve will be open and start the 50% solenoid valve, the 
startup is complete, enter energy regulation process.  
Energy regulation: when cycling water outlet temp. > setting temp. + download temp. difference, the 
chiller will upload from 25% to 100%, or will keep the original energy. When cycling water outlet temp. <  
setting temp. - download temp. difference, the chiller will download from 100%~25% until stop working. The 
condensed fan started all without be controlled by pressure. When compressor run in 50% lasts for over 30 
minutes, compressor will unload to 75% compulsively, then upload or download by adjusting temp. condition. 
The chiller will download to 75% compulsively when the discharging pressure is over 2.25MPa(revisable) and 
will not upload to 100% unless the pressure resume to 2.0MPa(revisable). 
Stop the chiller: the current capacity change to 25% operation when stop the chiller, 1 minute later the 
compressor stops, 10 seconds later the fan motors stop in turn, fan motors stop at 5 seconds interval in turns,  
5 seconds later stop the 25% valve and 4-way valve, another 1 minute(revisable) later stop the water pump.  
Defrost: there are two types to defrost: pressure defrost and temp. defrost. 
a. When the suction pressure is less than the defrost pressure setted value, judge if the defrost interval is 
met, enter defrost if it meets the interval and quit defrost compulsively if reach the max. defrost time. when 
during defrost, the condensing fan motor stops and 4-way valve reverse when the compressor download to