The Electric Diesel Engine industry focuses on the repair and production of electrical rotating equipment and components—specifically motors and generators used in electric diesel locomotive engines. The components that make up these engines include AC and DC Traction motors, Stator coils, Armature Coils, Field Coils, Rotor Coils, and Edge bent coils. Most of these components require precision high temperature insulation materials and abrasion protection materials.
Several different styles of insulating materials are used to protect the equipment components against arcing and physical abrasion. PTFE coated fiberglass fabrics, pressure sensitive tapes, uncoated fiberglass fabrics and tapes (silicone adhesive), Kapton® Films, and Silicone rubber are often used for these purposes.
Electric Motor Rewind –the rewinding of magnet wire to the motor core. The wound wire is insulated to class “H” 180°C rating. This process applies to electric motors of any size, from small household appliance motors to larger industrial motors for heavier equipment.
Class H fiberglass tape is used to protect and insulate the wound wiring core during the insulation phase of the repair of electric motors. The tape offers protection from abrasion and provides electrical insulating properties. The Class H listing means that the tape has a rated heat tolerance of 180°C (356°F) . This is a conservative rating since the PTFE Group fiberglass tape has the ability to function at temperatures approaching 250°C / 482°F. Often, the fiberglass is further reinforced with cured resins and/or varnish. This varnish process encapsulates the wrapped wiring to keep it secure and fixed.
The focus of this sub-industry is the manufacture of Dry Cell Transformers which are essentially power converters. Dry cell transformers (large and small) contain coils that operate in air as opposed to insulating oil. As with all transformers, dry cell transformers are electrical devices used to transfer an alternating current or voltage from one electrical circuit to another by means of electromagnetic induction.
The copper coils are insulated by woven fiberglass tape. Woven fiberglass is an excellent insulator which is why PTFE Group fiberglass tape is often used to wrap the coils and wiring. The tape is, in turn, covered with a curing varnish that is then oven-cured. The ideal tape for this purpose is Class H insulating tape with silicone adhesive. Since PTFE Group silicone adhesive tapes neither dis colour nor burn, they are a preferred choice for this application.