Motor Rewinding, Electric motors are relatively simple mechanical devices, but rewinding the coils on a motor is a precise task that should only be undertaken by those who with experience in mechanical or electrical repair. A mistake or poorly-performed rewind job will result in a motor that doesn’t work. At that point, your only options are to buy a new motor or to take it to a professional shop for repair. So if you don’t understand the terminology, you shouldn’t be rewinding a motor; once you start removing the original coils, there’s no going back.
Dismantling and rewinding a motor is a very time-consuming task. if you don’t have professional equipment. you will need the following tools to carry out this task.
1.Screwdrivers, hammers, wrenches.
-Copper wire, Isolation paper, Stator lacing thread, Spray lubricant (WD-40 or similar), Motor lacquer.
What is rewinding?
Rewinding is the process of replacing the coil of an electric machine which has been destroyed due to overloading. In this study, we are going to focus on how an electric motor is rewound including all the various steps that are involved.
Dismantling the motor:
To begin the rewinding process, dismantle the motor(Remove the cover from both ends and the armature) until you are left with something as bellow.
Drawing the motor:
After studying the motor, the most challenging stage will be to draw the motor. Remember the main goal is to replace the motor with the same characteristics as prescribed by the manufacturer on the nameplate. So drawing the motor will be to reproduce the original diagram from just looking at it.
Identifying type of coiling:
To be able to draw the motor, we first have to identify the type of coiling(Whether it’s single coiling, double coiling, double-single etc.)
Removing old coils:
At the point, you will have to remove all the old windings from the motor. you do this by cutting all the windings from one end. Try to count the total number of conductors per slot which will give you the number of turns when making your own coils.
Heating the motor:
Place the motor in an oven for about 45 minutes at a temperature of about 90 degrees so that the insulation papers and the insulation coating on the coils can melt out. after heating clean the motor internally using any hard pointed object and blow compressed air into the slots to get rid of any foreign objects.
Inserting insulation papers:
Insulation papers help to avoid any direct contact between the coils and the slots. After inserting the insulation papers, the next step will be for you to make the coils. to do this, you first need to determine the diameter of the coiling wires using a micrometer. then take a sample wire and place inside the slot using the inner span to get sample loop.
Forming the coils:
Use the sample wire above to set the rewinding machine and start making the coils. Don’t forget to set the counter and keep an eye on it because it’s going to determine the total number of turns.