Normally closed PSR?

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.

Connect the chlorinator (usually very low amps) to the output of the well pump relay through the normally closed contacts of a DPDT relay.

Connect the coil of that chlorinator relay to a voltage source that is associated with turning on the sprinkler. You can get a relay with a coil voltage the same as the voltage that becomes available when the sprinkler comes on. Check Grainger.

When the sprinkler is off, the chlorinator is connected to the well pump and will run when the pump runs.

When the sprinkler is on, the chlorinator is disconnected from the well pump relay.

Why not simply put the chlorinator on a flow switch. It will run when water is running in the house and not when the sprinklers are running.
bob...

Love that - really simplifies matters. Thanks very very much!

You could have flow in the house due to water demand at the same time you are running the sprinkler.

The flow switch should go in the line supplying the sprinkler system and be wired to your chlorinator through the Normally Closed contact of the switch. Then when the sprinkler flow occurs the chlorinator will be disabled.

It looks like you will need a relay if you want to disconnect both of the 220 volt hot wires to the chlorinator.

If he still wants chlorinated water in the house when the sprinklers are running, putting the switch in the sprinkler pipe would disable the feed pump altogether.

The flow switch can be configured either way however and can be put in line with one of the two 115 volt lines to start/stop the feed pump.

bob...