3-Wire and 2-Wire Submersible Motor Features

• 3-wire submersible well pumps with Franklin motors require a separate control box that is mounted in a dry location above ground.
• The start capacitor in the control box energize the starting winding to get the motor nearly up to speed, then the relay contacts open and disconnect the start winding and the start capacitor for the remainder of that cycle.
• The 3-wire motor has four wires. A red (start wire) a black, a yellow and the green ground wire. The red, black and yellow all connect to their perspective terminals in the control box. The green is connected to the ground terminal. The other two terminals in the control box are the L1 and L2 connections which accept the input power. The control box includes a start capacitor, a relay and sometimes an overload protector and a run capacitor. The run capacitor stays in-line all the time and does not need a relay to disable it.
• If the pump gets locked due to sand or grit, the 3-wire motor depends on the start capacitor to have enough strength to kick start the pump. If it does not have enough strength the pump and motor must be pulled for service.
• If there is a problem with capacitors or relays, the 3-wire aboveground control box can be repaired easily.

2-Wire Submersible Pump and Motor

• 2-wire submersible well pumps with Franklin Motors have a biac solid state start switch inside the motor.
• The biac solid state switch energizes the start winding in the motor to get it up to speed. When the motor is almost at normal RPMs, the solid state switch disconnects the start winding for the remainder of that cycle.
• The motor has three wires. Two of these wires are black and connect directly to the power source. The third wire is the green ground wire.
• If the pump gets locked up due to sand or grit, the biac switch will kick the motor in a reverse direction then back in the forward direction to try to break the pump loose. If it can’t the pump the pump and motor must be pulled and serviced.
• If there is a problem with start control, the 2-wire pump must be pulled and serviced