Rx1559
New Member
Hello! I would like to learn when to use a relay and when to use a contactor, for controlling power to my submersible well pump. I am replacing the old system, which uses a pressure switch to signal the pump to come on and off, with a fancy new 12V DC SmartWater pump controller.
My water system has power coming in as two legs of a single-phase 230v (and a yellow wire which I assume is a ground, need to get on-site to confirm) running to a SquareD 230V pressure switch. The load side of the pressure switch then runs to a PumpSaver 233P, and in turn to a CentiPro Pump Controller box CB15412CR, and then runs down the wellhead as 3 wires (plus ground) to the pump. I am pretty sure the pump is something like a CentiPro 1.5hp 230v 10A 3450RPM pump.
My well guy said I could just replace the SquareD pressure switch with relay instead of using a contactor; specifically, this one:
Medium-Current Relay DPDT, 8 Terminals, 12V DC Input
I just want to understand this decision because I like to know how this stuff works: When is it appropriate to use a contactor, and when is it appropriate to use a relay, for this application? Does the capacitor-start / capacitor-run, and relay in the Pump Controller box have anything to do with this decision?
My water system has power coming in as two legs of a single-phase 230v (and a yellow wire which I assume is a ground, need to get on-site to confirm) running to a SquareD 230V pressure switch. The load side of the pressure switch then runs to a PumpSaver 233P, and in turn to a CentiPro Pump Controller box CB15412CR, and then runs down the wellhead as 3 wires (plus ground) to the pump. I am pretty sure the pump is something like a CentiPro 1.5hp 230v 10A 3450RPM pump.
My well guy said I could just replace the SquareD pressure switch with relay instead of using a contactor; specifically, this one:
Medium-Current Relay DPDT, 8 Terminals, 12V DC Input
I just want to understand this decision because I like to know how this stuff works: When is it appropriate to use a contactor, and when is it appropriate to use a relay, for this application? Does the capacitor-start / capacitor-run, and relay in the Pump Controller box have anything to do with this decision?