Fast and expert maintenance

Field Coil Repairs

An image of the copper wires we use for rewinding

What Is a Field Coil—and Why It Matters

Without a working field coil, your DC motor doesn’t run. It’s that simple. Field coils generate the magnetic field that drives the motor. Typically made from insulated copper wire wound around laminated steel cores, these coils are arranged to produce north and south poles—creating the force that keeps your equipment turning. Main poles supply the flux; interpoles improve commutation. Together, they’re essential. If one fails, performance drops—or stops entirely. This is why regular field coil repair or maintenance are essential for a good functioning motor.

Common Causes of Field Coil Failure

Field coils fail for a number of reasons—but three are most common:

  • Earthing: Damaged insulation or carbon dust from worn brushes can expose the coil, causing it to short against the frame. Often, this can be repaired with steam cleaning, impregnation and stoving.
  • Burnouts: Overheating—caused by vibration, overload, or electrical faults—can melt the wire and break the circuit. When this happens, field coil replacement is usually the only option.
  • Lead Failures: The flexible leads connecting coils to terminals can wear or break. If we can make a clean, insulated connection, we can replace the leads and save the coil.
An image of an AC motor
An image of two of our engineer rewinding motors

Our Field Coil Rewind Process

When a field coil repair isn’t possible, we rewind. Fast. In our state-of-the-art winding workshop, we replace damaged coils with precision-wound, high-grade copper—matching the original performance, often improving it. Here’s how we do it:

    1. We remove the damaged coil while retaining the steel pole (if undamaged).

 

    1. A new coil is wound under tension using enamelled copper wire or strip.

 

    1. Each coil is dipped in resin to meet the correct insulation class. 

 

  1. We refit the assembly, reconnect, and rigorously test for resistance and insulation.

 

The result? A fully restored motor or generator—tested, proven, and built to last.

Case Studies

This is why

1. Speed of service

Reducing your downtime is our main priority. That’s why, from the moment you call to the final report, we move fast. No delays. Just results.

2. High-quality service

With over 100 years experience, we’ve built a reputation on precision, excellence, and constant improvement. You expect the best—we deliver it.

3. One-stop shop

The vast experience of our staff, combined with our state-of-the-art workshop, provide us with flexibility. We do not only repair – we manufacture.

4. ATEX motors specialists

Repairing all types of ATEX motors. We are an AEMT Ex Registered Repairer recognised for our quality systems and professional repair standards.

Contact Mawdsleys Today for Swift Motor Support