Insulating Varnish Overview
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call us 877.474.8209 M-F 5:30am-5:30pm PST What is insulating varnish? How is insulating varnish applied? Benefits of Electrical Resin FAQ Fibrous material, such as paper, was traditionally used as the primary insulation on inductor coils. To improve the insulation properties of the coils without having to use wire with thicker insulation, a secondary insulation (i.e. impregnation resin) was used to "impregnate" the assembled coils of wire. Primary insulation is considered impregnated when all the spaces and gaps between fibers are completely filled by the impregnation resin, which is why secondary insulation and impregnation resin are interchangeable terms. By this definition, a winding can be impregnated even if there are still spaces between coils--as long as the spaces between the fibers of the primary insulation are filled in. Insulating varnish refers to the electrical insulation used for impregnating coils of wire, such as the inductor coils found in transformers. It is also known as impregnating or transformer resin. Keep in mind that insulating varnish may refer to the primary insulation (wire enamel) used to initially coat a bare conductor, or it may refer to the secondary insulation that is applied to assembled windings of enameled wire. Insulating Varnish Overview Insulating Resin Guides » Insulating Varnish Overview Since the vast majority of people prefer to purchase enameled wire rather than make their own, we will use the term “insulating varnish” to refer to the secondary insulation for assembled windings, such as coils on transformers, motors, and generators. Insulating varnish comes in liquid form and can be sprayed, brushed, or trickled onto coil windings. The method of application depends on the size of the coil and the desired production rate, and different methods for insulation varnish, such as the dip and bake method, vacuum pressure impregnation (VPI), and trickle impregnation can result in different degrees of impregnation of the winding. The use of solvents also plays an important role in diluting insulating varnish so that it will flow more easily. Why would you need to use electrical resin when most wires already come with a layer of primary insulation? Electrical resin: Provides protection from mechanical damage Dampens vibrations by immobilizing windings Prevents moisture and other foreign matter, like dust and debris particles, from getting in between coils and damaging the primary insulation Increases the dielectric strength (i.e. improves insulating properties) of fibrous insulation (e.g. paper was commonly used as primary insulation for the coils in very old transformers) Helps carry heat away from the windings either to the surrounding air or to the core Electrical resin (i.e. secondary insulation or impregnating resin) is used to provide extra protection for wire windings and coils. This is especially important for inductor coils where the coils are packed so tightly that internal damage from coils rubbing against each other could easily cause their primary insulating layer to wear out. What applications commonly use winding varnish? Inductor coils in motors, generators, transformers (e.g. stator and rotor windings), as well as for ham radios, antennas, tesla coils, solenoids, and tattoo machine coils. Can TEMCo's insulation be used on all types of magnet wire? Yes. Please see our full line of magnet wire. What is the dielectric strength of TEMCo's insulating varnish? At 25°C (77°F), TEMCo's winding varnish can withstand up to 3300 volts per mil of insulation thickness (a mil is 1/1000 of an inch).
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Transcript of Insulating Varnish Overview
call us
877.474.8209 M-F 5:30am-5:30pm PST
What is insulating varnish?
How is insulating varnish applied?
Benefits of Electrical Resin
FAQ
Fibrous material, such as paper, was traditionally used as the primaryinsulation on inductor coils. To improve the insulation properties of the coils withouthaving to use wire with thicker insulation, a secondary insulation (i.e. impregnationresin) was used to "impregnate" the assembled coils of wire.
Primary insulation is considered impregnated when all the spaces and gapsbetween fibers are completely filled by the impregnation resin, which is whysecondary insulation and impregnation resin are interchangeable terms. By thisdefinition, a winding can be impregnated even if there are still spaces betweencoils--as long as the spaces between the fibers of the primary insulation are filledin.
Insulating varnish refers to the electrical insulation used for impregnating coilsof wire, such as the inductor coils found in transformers. It is also known asimpregnating or transformer resin.
Keep in mind that insulating varnish may refer to the primary insulation (wireenamel) used to initially coat a bare conductor, or it may refer to the secondaryinsulation that is applied to assembled windings of enameled wire.
Insulating Varnish Overview
Insulating Resin Guides » Insulating Varnish Overview
Since the vast majority of people prefer to purchase enameled wire rather than make their own, we will use the term “insulating varnish” to refer to the secondaryinsulation for assembled windings, such as coils on transformers, motors, and generators.
Insulating varnish comes in liquid form and can be sprayed, brushed, or trickled onto coil windings. The method of application depends on the size of the coil andthe desired production rate, and different methods for insulation varnish, such as the dip and bake method, vacuum pressure impregnation (VPI), and trickleimpregnation can result in different degrees of impregnation of the winding. The use of solvents also plays an important role in diluting insulating varnish so that it willflow more easily.
Why would you need to use electrical resin when most wires already come with a layer of primary insulation?
Electrical resin:Provides protection from mechanical damageDampens vibrations by immobilizing windingsPrevents moisture and other foreign matter, like dust and debris particles, from getting in between coils and damaging the primary insulationIncreases the dielectric strength (i.e. improves insulating properties) of fibrous insulation (e.g. paper was commonly used as primary insulation for the coils in veryold transformers)Helps carry heat away from the windings either to the surrounding air or to the coreElectrical resin (i.e. secondary insulation or impregnating resin) is used to provide extra protection for wire windings and coils. This is especially important for
inductor coils where the coils are packed so tightly that internal damage from coils rubbing against each other could easily cause their primary insulating layer to wearout.
What applications commonly use winding varnish?Inductor coils in motors, generators, transformers (e.g. stator and rotor windings), as well as for ham radios, antennas, tesla coils, solenoids, and tattoo machine
coils.
Can TEMCo's insulation be used on all types of magnet wire?Yes. Please see our full line of magnet wire.
What is the dielectric strength of TEMCo's insulating varnish?At 25°C (77°F), TEMCo's winding varnish can withstand up to 3300 volts per mil of insulation thickness (a mil is 1/1000 of an inch).
What is the cure temperature for TEMCo's varnish, and how long does it take to cure?135°C (275°F) for 4 hours or 150°C (302°F) for 2 hours.
Will TEMCo's insulating varnish cure without baking?No, our resin is thermal-cured.
Is TEMCo's varnish flammable?Yes. Please refer to our Material Safety Data Sheet for precautions and proper cleanup procedures.
Is TEMCo's varnish waterproof after curing?Yes.
Can I apply more than one layer for greater film thickness?Yes.
What size containers are available?4 oz., 1 quart, 1 pint, 1 gallon, and 5 gallons. View our full product line here.
Will adding winding varnish to my coils affect impedance?No, winding varnish will not affect impedance.
Can TEMCo's winding varnish be sprayed on?No. If you are using TEMCo's insulating varnish as impregnating resin, then sprays will not work. The varnish will not penetrate into the winding.
Can I insulate bare wire with TEMCo's winding varnish?Yes.
