How To Wire A 220 Well Pressure Switch (4-Step Guide)

A well pressure switch is an important part of delivering water throughout your home; when it quits, it can cause a major disruption to your life! 

In this guide, you will learn:

  • How to wire up a well pump pressure switch safely!
  • Wiring for the two types of well pump switches
  • Signs your switch is ready to be replaced
  • And more!
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Does it seem like your water pressure is much lower than normal? Do you think your well pump cycles on and off all the time? 

These are signs that your pressure switch is bad.  If you are here, you are trying to decide if this is something you can do on your own.  I am here to tell you: Yes, you can, if you follow our simple guide!

As a licensed electrician, I ask that if you are uncomfortable or run into problems at any time while working on the well pump pressure switch, please stop and call a local electrician to come help finish the job.

Keep reading to learn the 4 steps on how to wire a 220V well pump pressure switch! 

Most Pressure Switches Use 5 Or 6 Wires

Wiring up a well pressure switch is not a difficult task. The majority of switches only use 5 or 6 wires total! To locate your switch, check around the three usual spots that switches are installed: 

  • On the jet pump or right at the well pump that is located near the water pressure tank
  • On a water tank tee or inline with a water pipe that is near the water pressure tank
  • On the water pressure tank itself 

For the most part 220V well pressure switches use a 2-wire submersible pump set up.

Take A Picture of How It's Wired

An important part about wiring up a well pump pressure switch is knowing where the wires need to go.  If you are replacing an old switch, an easy way to have a wiring diagram is to snap a picture using your phone BEFORE you unwire it! 

After you have shut the power off you will want to release the pressure in the tank by running a faucet for a minute.  Verify you have no pressure by looking at the pressure gauge, it should read 0 PSI.

Supplies & Tools Needed 

  • Voltage Meter - A voltage meter allows you to verify the power is off 
  • Screwdriver - A screwdriver will be used to remove and reinstall the cover and make the wire terminations.
  • Wire Strippers - Wire strippers are used to strip the insulation off the individual wires
  • Wire Crimpers - Wire crimpers are used to crimp fork connectors on the ends of the individual wires 
  • Fork Connectors - Fork Connectors get crimped on the end of the individual wires allowing for a secure connection

4 Steps To Wire A Well Pump Pressure Switch

Step 1 - Verify There is No Power and Release Pressure

Turn off the breaker feeding your well pump. 

Remove the cover and verify there is no power on the well pressure switch wires you are hooking up by using your voltage tester.

Carefully use one probe to touch the end of a hot wire while touching the other probe to a ground wire; your meter should read zero volts. Repeat for the other hot wire. 

After the power is off run a faucet for a minute to release pressure from your switch; your pressure gauge should read 0 PSI.

Read Also >> How To Wire A 3-Way Light Switch?

Step 2 - Strip the Ends of the Wire and Crimp on the Forks 

Using strippers, remove about 1/2 inch of insulation off the wire. 

Place the barrel of the fork connector over the end of the wire and use your crimpers to crimp it onto the wire. 

Verify you have a good crimp by giving the connector a good tug; loose connections can cause problems with passing power or create a hot spot which can lead to fire.  

Step 3 - Wire the Pressure Switch 

Thread the wires back into the switch.  Establish what wires come from the motor and what wires are power wires. 

Wiring a Two Wire Switch

There will be a termination bar holding 4 screws. The incoming power will land on the line terminals, labeled as L1 and L2.  These are the outside 2 screws. The wires are interchangeable.

The motor leads will land on load terminals, labeled as T1 and T2 or M.  These are the middle two screws and the wires are also interchangeable. 

The ground will land on the green screw typically located at the bottom of the switch body.

Wiring a Three Wire Switch

The incoming power will land on the line terminals labeled as L1 and L2.  These are the outside 2 screws. The wires are interchangeable.

The motor leads should be red, black, and yellow.  They will land on their respective screws labeled R, B, and Y. The ground will land on the green screw typically located at the bottom of the switch body.

Read Also >> How To Wire A 220-Volt Outlet?

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Step 4 - Replace cover and Repower

Double-check the connections are secure: no loose fork connectors, and the screws are tightened down. 

Carefully fold the excess wire in so the cover can easily slide back into place without pinching the wires. Once complete you can turn the breaker back on.  

Frequently Asked Questions

How Do You Wire A 220V Pressure Switch For Well Pumps?

First, verify the power is off.  Run the wires into the switch.  The power wires, L1 and L2, will land on the outer two  most screws labeled as such; these wires are interchangeable. The motor wires will land on the middle two screws labeled as either M or T1 and T2; these are also interchangeable. The ground wire will land on the ground screw. Tuck the wires in so you can put the cover on, install the cover, and then turn the power back on. 

How Do You Wire a 230-Volt Pressure Switch?

Verify power is off, then run the wires into the switch. Power wires, L1 and L2, will land on the outer two most screws of the terminal strip. The motor wires will land on the two center screws labeled as either M or T1 and T2.  Then the ground wire will land on the ground screw. Tuck the wires in nicely so you can reinstall the cover and turn the power back on.  

Where Do The Wires Go On a Pressure Switch?

On the inside of the switch cover there should be a wiring diagram you will be able to follow.  There will be two sets of wires, ones coming from the electrical panel and ones coming from the motor.  The power wires will land on the outer two most screws labeled L1 and L2, and the motor wires will land on the center two screws labeled T1 and T2. Then the ground wire will land on the ground screw.

How Do You Wire A Square D Pressure Switch For Well Pumps?

Under the cover you will find four screws.  The power wires, L1 and L2, will land on the far outside two screws of the terminal strip. The motor wires will land on the two center screws labeled as either M or T1 and T2.  Then the ground wire will land on the ground screw. Tuck the wires in nicely so you can reinstall the cover and turn the power back on.

Read Also >> How To Wire A Bath Fan & Light On Separate Switches?

Final Thoughts On Wiring 220-Volt Well Pump Pressure Switches

There is nothing more frustrating than getting ready to leave just to find you have no water pressure. There is no need to add to the stress by tacking on a handyman bill when you can do it yourself!

Safety is the most important thing, so make sure you have the power turned off before you begin your work.  Take the time to look over the pressure switch and how it is wired before you begin; this will help ensure you get it wired back up correctly.

If you have any doubts, questions, or are no longer feeling comfortable about working on it, be sure to give your local electrician a call to come and give you a hand!

I hope you enjoyed this Home Inspector Secrets guide!

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