Industrial Motor Windings & Motor Repair — Asbestos Exposure Crosswalk
What This Equipment Is
Industrial AC and DC motors are the workhorses of every manufacturing plant, power plant, refinery, brewery, and large building. From small fractional-horsepower fan motors to multi-thousand-horsepower compressor and pump drives, the population in a typical industrial facility numbers in the hundreds or thousands.
Historical motor insulation systems — particularly in pre-1980 medium-voltage motors and DC motors — used asbestos-bearing components:
- Conductor insulation — asbestos paper tape between turns and around coils
- Slot insulation — asbestos pressboard or sheet between coil and slot wall
- Coil-end blocking and tying cord — asbestos cord and pressboard
- Brush-rigging insulation (DC and synchronous motors) — asbestos millboard barriers
- Motor lead bushings — asbestos-bearing barrier components
- Bearing-housing gaskets — asbestos sheet gaskets
Why Motor Rebuild Work Was an Asbestos Exposure Pathway
When a motor fails, the typical industrial response is to send it to a motor-rebuild shop for stripping, rewinding, and reassembly. The rebuild process opens the motor fully and exposes the rewinder to the legacy insulation system:
- Disassembly — removing end bells, exposing windings
- Burn-out — most rebuild shops use a controlled-temperature oven to bake the old windings out of the slots. Burn-out drives off the organic varnish and binders; any asbestos components are left as embrittled, dust-prone residue.
- Slot cleaning — mechanically clearing residue from the iron slots
- New winding installation — wrapping coils with replacement insulation
- Final cure and reassembly
Burn-out and slot cleaning are the highest-exposure steps. Motor-rebuild shop workers performed this sequence on hundreds of motors per year.
Manufacturers Named in Litigation Involving Motor Components
- General Electric — motor OEM named in installation/maintenance claims
- Westinghouse Electric — motor OEM
- Allis-Chalmers — motor OEM
- Reliance Electric — motor OEM
- U.S. Electrical Motors — motor OEM
- Louis-Allis — motor OEM
- Johns-Manville — asbestos paper, tape, pressboard
- Armstrong World Industries — electrical-grade asbestos products
- Raybestos-Manhattan — asbestos textile and tape products
Documented Product References
Images sourced from publicly available product-identification reference materials. Inclusion does not constitute a finding of liability against any company.
Trust Funds That May Apply
- Manville Personal Injury Settlement Trust
- Armstrong World Industries Asbestos PI Settlement Trust
- Raybestos-Manhattan Asbestos PI Trust
Trades Most Exposed at Motor Work
Motor-rebuild shop workers (rewinders, burn-out operators), industrial plant electricians performing field motor maintenance, contract electrical-rebuild crews, demolition crews handling vintage motors.
Jobsites in the Network
- Motor-rebuild shops and electrical-shop areas at every Missouri industrial facility operating a maintenance department
- Independent motor-rebuild shops serving regional industry
- See companion pages: Generators, Transformer Components, Electrical Arc Chutes
Compiled from publicly filed asbestos litigation, EPA / OSHA records on motor-shop abatement, and industry-publication histories. Product and company references reflect what has been alleged or documented in publicly filed litigation. This page does not constitute a finding of liability against any company. Not legal advice; consult a licensed attorney about your specific situation.