What s the difference between two and three wire sub motors?
A. Since Franklin Electric has been the motor manufacturer for practically every American submersible pump company in the United States up until recently; the information below will relate to only one brand of motor. The two wire Franklin 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. The three 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 a control box which is installed above ground in a convenient location. 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 power from the electric company. In this control box are a start capacitor, a relay and sometimes an overload protector and run capacitor. The two wire motor has a biac switch that energizes the start winding in the motor to get it up to speed.
