Any one no where I can locate a NC (normally closed) PSR (pump start relay) or a standard NO - PSR that can be modified to a NC status? I need to figure out how to shut off a chlorinator when sprinklers come on. Chlorinator is 220vac liquid injector model that is wired directly into the well pump switch. So it runs whenever the pump runs - regardless house or irrigation. My thought was an attemp to reverse the normal use of a PSR wired to the sprinkler controller. So instead of using the pump start relay sending a start signal to the 220vac well pump but rather a stop signal to the 220vac chlorinator. My problem is that standard PSR's are normally open I need to either find one that can be modified to be normally closed or possibly use a standard model in conjuntion with a DTDP (double throw double pole) relay as to reverse the normal usage. Any other ideas or help would be greatly appreciated.