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 as not waste chemicals as well as excessive wear on injector. 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 (pump start relay) 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 used 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.