Electric Motors - Explaining Lead-End & Shaft-End In Layman's Terms
You see it all the time when looking at the various rotations of motors – one might be listed as clockwise lead end and another might be listed as clockwise shaft end. Which perspective is lead end and which is shaft end? We’re going to answer this question for you today.
First, let’s start by getting the 10,000 lbs. gorilla out of the room. What is a lead? The leads on an electric motor are the attached wires or cables that come off the motor and connect to the power supply to energize the motor. Simply put, they’re the motor’s wires.
Knowing that the motor’s wires are called leads, it’s fair to assume that the lead end of a motor is the end of the motor in which the wires come off of it. The leads are almost always on the end opposite to the shaft in order to avoid cluttering the leads with whatever the motor is driving. Therefore, lead end is also called opposite shaft end. The one exception to this rule is double shafted motors. The leads need to come out of one end or the other and both ends have a shaft coming out, so there’s not much you can do.
To determine rotation from lead end perspective, you need to look at the end of the motor with the wires coming off of it and the shaft pointing away from you. To determine rotation from shaft end perspective, you need to look at the end of the motor with the shaft pointing directly at you.
Viewing a motor from a lead end perspective.
Viewing a motor from a shaft end perspective.
With lead end being opposite shaft end and shaft end being opposite lead end, the following are all true: Clockwise lead end is counter clockwise shaft end, clockwise opposite shaft end, and counter clockwise opposite shaft end. Clockwise shaft end is counter clockwise lead end, clockwise opposite lead end, and counter clockwise opposite shaft end.
It should be noted that most electric motor catalogs give the rotation from a shaft end perspective unless stated otherwise.