Winding Services

Doerr Motor and Pump is your local expert on motor windings. We complete the entire winding process in-house using only the best materials and processes to make sure your winding exceeds OEM performance and efficiency.  We offer quality rewinding of 3 phase and single-phase motors and pumps, DC motors and armatures, magnet coils, brake coils, industrial generators, and anything else containing windings. (We currently do not rewind transformers).  When we rewind your motor, you get a higher quality product at a fraction of the cost of replacing. Our winding process is detailed below.

 

Taking Data

Our process starts with detailed data collection and record keeping. Nameplate data, connections, and winding data are carefully recorded and kept on file. Our personal database of winding data contains 1,000’s of windings dating back to the 1940’s.

​

Core Loss Testing

We then perform a test of the iron core before the stripping process to ensure the integrity of the core and to make sure the core insulation does not decrease during the burn out process. We use the latest core testing technology from Lexseco. The MP7 software integrated in the Lexseco core loss tester generates a report for each stator tested. We use thermal imaging to detect hot spots in the iron core. This test is repeated after the burn out and stripping process where repairs can be made to a damaged core if necessary.

​

Burn Out

Stators are then processed in our Bayco burn off oven. This oven heats the stators to exactly 700 degrees to break down the varnish and insulation to make stripping and cleaning the stator quicker and easier. This oven can also be used to strip paint and other organic materials from metal parts for cleaning.

​

Prepping

The stripped stator is steam-cleaned with our hot water pressure washer.  We paint the iron core with an electrical insulating varnish after any iron repairs are made. We insulate the stator slots with the appropriate Nomex paper depending on the application. The stator is ready for wire.

 

Winding

Using the data collected coils are made on one of our two winding machines. We use Ultrashield inverter duty wire on all our rewinds. This wire has a thicker coating and is much more durable than standard magnet wire. Once the coils are inserted, The connections are brazed together using a silver copper alloy that is 10 times stronger than the wire itself. The windings are then tied down and tested. Our Baker Surge Tester is used to test the stator. The insulation is tested to 1500v to ensure it will withstand voltage spikes. A surge comparison test is performed to ensure the three phases are exactly balanced and that there are no shorts.  

​

Dip and Bake

A tried-and-true process of dipping the windings in electrical insulating varnish and curing in an oven. Stators are lowered into a tank of vanish and left to soak to ensure the windings are completely coated. Our varnish is tested by the manufacturer regularly to ensure the product is in prime condition. The stator is then loaded into our Steelman bake oven to cure. Our Steelman gas fired bake oven brings the stator up to curing temperature quickly and uses PID controllers and electronic gas valves to keep the temperature exactly at 300 degrees with no deviation allowing for a clean and accurate cure.

​

Finishing

The electrical tests are repeated after the curing process. Excess varnish is removed from the bore and masking compound is cleaned from machine surfaces. The windings are then coated with electrical insulating paint. At this point, the stator is ready for assembly.