How do you wire a DOL starter controlled by a pressure switch for a water pump?

Answer for USA, Canada and countries running a 60 Hz supply service.

The wiring of this type of installation is quite elementary. It is all about the control voltage for the magnetic contactor and having the pressure switch in series with the contactor's coil.

If the pump supply voltage is 120 volts, take a wire from L1 on the contactor and place it on the normally closed contact point on the overload block.

From the N.C. contact on the overload block take a wire to one side of the pressure switch.

From the output side of the pressure switch contact take the wire back to one side of the contactor's coil.

Connect the other side of the contactor's coil to the neutral wire from the supply.

Now you will have three components in series with each other. The overload block, the pressure switch and the contactor's coil as the load of the circuit. When the pressure switch closes due to low pressure the coil will be energized.

If the pump motor goes into an overload condition, the overload block contacts will open and de-energize the contactor's coil and the pump will shut off.

As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.

Before you do any work yourself,

on electrical circuits, equipment or appliances,

always use a test meter to ensure the circuit is, in fact, de-energized.

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.