Is it safe to use a two wire 220 volt water well pump (having three wires) at my home ? I thought all 220 used four wires ! Thank you, Dal.

Hi Dal:

The electrical trade is confusing. For your situation: 14/2 is really 3 wires (2 hots and a ground), 14/3 is 4 wires; (2 hots, a neutral and a ground). Neutrals would allow 120 V lamps, pipe heaters etc.

ALWAYS run a ground. 14/2 with ground MAY be acceptable based on the HP of pump and distance. What we need to know is FLA (Full Load Amps) and distance to size the wire.

Electric ovens and dryers are very odd because of code enhancements.

There are specific code regulations for wiring pump motors.

Basically, you need the electrical specifications from the metal tag on the pump.

I know you said you need 220, but the standard is currently 240 VAC.

240 is derived from the combinations of two hots.

For the pump, you need to know whether the pump requires only 240 VAC or 120/240.

If it is a straight 240, then you only need a two wire with ground. Neutral (White) would be used a hot conductor. With either Black or Red (Sharpie pen coloring) to signify that the White conductor is now a hot conductor.

Before you run out and purchase conductors, you need to know the amperage required by the pump and the distance from the source to the pump.

This information is necessary to size the conductors to carry the required voltage and amperage the distance to the pump.

NO, not all "220" uses four wires. In fact NO 240v uses four wires, which implies the circuit has a neutral. The moment you introduce a neutral into the circuit it becomes a 120/240v circuit.

A typical residential well pump would never be 120/240v. It would be 240v. There are some high-end 3-phase variable speed constant pressure pumps that use a VFD, but that is another issue entirely.

A 2-wire pump has a built-in starting capacitor, a 3-wire pump is to be used with an external control box, usually near the pressure switch/tank. They are NOT interchangeable.

A solution to your situation would be a question for a well guy or qualified plumber. I will say, if you have a 2-wire pump it can be wired directly with 240v through the pressure switch.