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Piedmont Plastics | Plastic Supplier

Electric Insulating Panels

An overview of electrical insulating panels, the materials we offer, and typical material requirements for substation equipment.

Your Branch: Columbus Zip code: 43229 |

Electric Insulating Panels for Substations and More

Applications like substation equipment panels, switchgear enclosures, and control cabinets require mounting surfaces that can withstand demanding electrical and environmental conditions over decades of service. These boards must support heavy components while maintaining reliable electrical insulation under continuous voltage, mechanical loading, and changing environmental conditions. High dielectric strength, moisture resistance, low cold flow under sustained loads, and excellent dimensional stability are all essential for long-term performance.

Unlike wood or metal mounting surfaces, thermoset insulating boards provide both structural support and electrical insulation in a single material. They resist moisture absorption, maintain their shape over time, and help reduce the risk of electrical tracking or insulation failure in critical power distribution equipment. As a result, they are widely used for mounting terminal blocks, relays, busbar supports, disconnect switches, and other electrical components found throughout substations and switchgear assemblies.

Piedmont Plastics supplies materials for electric insulating panels that are engineered for demanding applications. Available in a range of sizes and thicknesses, these materials provide the electrical insulation, mechanical strength, and dimensional stability required for switchgear, transformer control cabinets, and other power distribution equipment.

Material Options

Piedmont Plastics supplies specially formulated laminates and other materials for electric insulating panels.

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With over 100 years of combined product knowledge and industry experience, we are confident our plastics experts can help you find a solution for your application.

What You Should Know...

Material Performance Requirements

  • Dielectric Strength

    Withstands high voltages for dependable insulation.

  • Moisture Resistance

    Resists moisture absorption for reliable performance.

  • Low Cold Flow

    Maintains shape under continuous mechanical load.

  • Dimensional Stability

    Retains precise dimensions over time.

Why Piedmont?

Our Solutions and Services

For more than 50 years, Piedmont Plastics has been a trusted source for high-performance materials, industry solutions, and value-added services. Our customers count on us for:

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1

Wholesale Distribution

A trusted wholesale supplier with a broad selection of performance plastics.

2

Local Inventory

Stocked at locations across North America for fast, convenient access.

3

Fabrication Support

Custom cutting and fabrication services to help meet your exact specifications.

4

On-Time Delivery

Reliable logistics to help keep your projects on schedule.

Frequently Asked Questions

Piedmont Engineering Grade® (PEG®) Insulating Panel is a specially engineered phenolic paper laminate that supports substation applications that require exceptional dielectric strength and reliable electrical insulation.

The Piedmont Engineering Grade® Insulating Mounting Board material has ASTM D709-17 Type I Grade XXX, MIL-I-24768/10 PBE Rev. 2/25/1992, and ANSI/NEMA IM 60000-2021 Grade XXX certifications.

Insulating panel boards can be installed in junction box panels and doors, electrical enclosure panels, resistor mounts, circuit breaker and switch mounting panels, transformer support and mounting components, capacitor bank mounting panels, and relay and instrumentation panels. Essentially, any application requiring a rigid, high-dielectric insulating panel.

Phenolic paper laminate combines the mechanical strength needed to support electrical components with the dielectric properties required to electrically isolate them. Unlike wood, it resists moisture absorption, offers more consistent electrical performance, and maintains dimensional stability over time. Compared to metal, it provides electrical insulation without requiring additional insulating components.

Yes. Moisture-resistant phenolic paper laminates like Piedmont Engineering Grade® Insulating Panel are commonly used in outdoor substations and other electrical applications where humidity and occasional moisture exposure are expected. These materials are designed to resist moisture absorption and maintain dimensional stability. For installations with prolonged direct UV exposure, consult your Piedmont Plastics sales representative to ensure the material is appropriate for your project's environmental conditions.

Yes. Piedmont Plastics offers value-added fabrication services, including cutting insulating mounting panels to your specified dimensions before shipment. Pre-cut panels can help reduce on-site machining, simplify installation, and minimize material waste. Contact your local Piedmont Plastics branch to discuss your size requirements and fabrication needs.

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