Insulating Varnish FAQ

What Is Insulating Varnish?

Insulating varnishes are resins like epoxies or alkyds used to protect high voltage machines such as transformers, motors and generators from electrical failure. They are applied over electrical conductors to provide a layer of electrical isolation and prevent shorting. While very similar to conformal coatings, these systems have superior dielectric properties, which makes them a better choice for applications like insulating windings and coils.

How To Use Red Insulating Varnish

Red insulating varnish is an alkyd resin with exceptional dielectric strength, used to electrically isolate conductors in windings and coils. It is applied like a conventional paint, by dipping, brushing and spray. However, the sheer size of some motors renders these methods unfeasible. In such circumstances, vacuum impregnation is employed, where large vacuums transfer liquid resin from a holding tank to a coating chamber, essentially encapsulating exposed wires.