AIR COOLED SCROLL CHILLER CONTROL
11
2 MAIN LOGIC
2.1 Cooling Mode
In cooling mode, the four way valve is always off as long as the controller is energized and it
hasn’t anything to do with the states of compressor and fan.
Tin=T_Cin+ΔTXN
Tout
=T_Cout+ΔTXN+T
Tout
=T_Cout+ΔTXN+T
Tin
=T_Cin+ΔTXN
(1)Control of compressor
For the module n, N=n & 0x03,ΔT=0.5,T=0.3.Compressor 1 and 2 will start and stop in fixed
time.
Compressor 1:
When Tin≥T_Cin+ΔT×N, compressor 1 is on.
WhenTout≤T_Cout+ΔT×N, compressor 1 is off.
Under other conditions, it keeps original.
Compressor 2:
When Tin≥T_Cin+ΔT×N+T, compressor 2 is on.
When Tout≤T_Cout+ΔT×N+T, compressor 2 is off.
Under other conditions, it keeps original.
(2)Control of fan
Dual-fan system
If both of the compressors are off, fan A will be off. If either of the compressor or both of them are
on, fan A will be on.
4-fan system
If compressor 1/2 is off, fan A/B will delay 30s to be off.