i use four compact screw type compressor(bitzer brand) in a chiler and i dont have any idea for capacity control(it has four step unloader)
do you have any experience with bitzer compact screw compressor?
See chapter 2. Are you using a frequency inverter ? If so you don't need to use CR1/CR2, only CR3 to unload at startup and CR4 pulsating to return the oil.
If you don't have an inverter you can either use step capacity (25%/50%/75%/100%) or infinite control (by pulsating CR3/CR4 you control the slider).
Usually infinite control provides better accuracy and is good for quick reaction, like regulating chiller outlet temperature.
Step capacity is good for slow response, like regulating on chiller inlet temperature.
Hope this helps!
i cant understand !!!
i have a four stage thermostat for control four compressor.
now i cant undrestand how can i do that?
i dont have any experience with this compressors.