How do I know if my submersible pump is a 2-wire or a 3-wire?

The difference between a 2-wire and 3-wire pump is based on the type of motor that is used. A 3-wire single-phase motor requires a control box with a starting capacitor. Because of this starting arrangement, the motor requires three “hot” leads (plus a lead for the ground connection) to operate correctly. It is called a “3-wire” due to the three “hot” leads, though there are actually four wires when you count the ground wire. The 2-wire motor requires no control box because is does not use a starting capacitor. Instead, a 2-wire motor has a built-in electrical device that is used to get the motor started. This only requires the pump to have two “hot” leads (plus ground), which is why it is called a “2-wire” pump. The confusion sets in when counting the total number of wires as a 2-wire pump actually has three wires and a 3-wire pump has four wires.

Stay Connected

Sign up today to keep up with the newest information from one of the Southeast’s leading suppliers of fluid handling equipment!

Interested In