Hello I need a bit of advice please.
The Denco computer AHU's at the place I am working have a by-pass valve / press regulator valve between the discharge and the evaporator, we had a unit and the capillary on the tev had worn through the expansion valve had closed but the the unit does not stop on LP because the by-pass valve opens the keep the pressure up. The compressor runs red hot and eventually stops on an internal hi temp cutout but then restarts when it gets cold. Is this by-pass valve needed I've seen lots of other denco ahu's and this valve is not fitted. I can see it might be useful if you were chilling water but this is only cooling air returning at about 25 c. The trouble is you never get a signal to the BMS that a unit is short of gas all that happens is the by-pass valve opens and keeps it going. Is is set wrong maybe. How should it be set up. I was thinking of winding it down so it does not operate and just let the unit stop on LP at least it would then indicate to the BMS there was a fault.
Thanks for any help