Substations run some of the highest-stakes electrical equipment in the power grid, and the materials mounting that equipment matter as much as the equipment itself. Piedmont Engineering Grade® (PEG) Insulating Mounting Board is a specially formulated paper based phenolic laminate built for exactly this kind of duty. Rigid enough to support heavy switchgear use and insulating enough to keep current where it belongs.
PEG Insulating Mounting Board is commonly specified for electrically insulating mounting boards used in substations, switchgear assemblies, transformer control cabinets, and other power distribution equipment. This article breaks down what PEG Insulating Mounting Board is, why utilities and contractors specify it, and where it fits in transformer and distribution (T&D) substation projects.
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What is PEG Insulating Mounting Board?
PEG Insulating Mounting Board is a NEMA Grade XXX phenolic laminate manufactured that is commonly fabricated into electrically insulating mounting boards and panels. Its proprietary construction is made from specially formulated layers of paper impregnated with phenolic resin, then compressed under heat and pressure into a dense, rigid sheet. The result is a structural material that holds its shape under load while resisting the flow of electrical current.
Grade XXX phenolic is a general-purpose industrial laminate, valued for a balance of mechanical strength, machinability, and dielectric performance for a wide range of electrical applications. Unlike glass-reinforced laminates, the paper reinforcement used in Grade XXX provides excellent machinability while still delivering the electrical insulation required for many mounting board applications.
It is also manufactured with the following certifications:
ASTM D709-17 Type I Grade XXX
MIL-I-24768/10 PBE Rev. 2/25/1992
ANSI/NEMA IM 60000-2021 Grade XXX
Note: Specific dielectric strength, mechanical, and thermal ratings should be confirmed with a Piedmont sales representative before specifying, since values can vary by thickness and production lot. Many electrical insulating laminates are UL Recognized for specific thicknesses and applications. If your project requires UL compliance, verify the applicable recognition and thickness coverage before finalizing your specification.
PEG Insulating Mounting Board Cut to Specification
Piedmont Plastics stocks PEG Insulating Mounting Board in standard sheet sizes and multiple thicknesses. We also offer custom cut-to-size fabrication for contractors and OEMs who need finished panels matched to exact project drawings. This flexibility allows contractors and OEMs to get panels that match their equipment layouts without compromising on material availability.
Common Applications
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Junction box panels and doors
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Electrical enclosure panels
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Control panel mounting boards
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Circuit breaker and switch mounting panels
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Transformer accessory mounting panels
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Capacitor bank mounting panels
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Relay and instrumentation panels
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Any application calling for a rigid, high-dielectric insulating panel
Why PEG Insulating Mounting Board Works for T&D Substations
Substations sit downstream from power generation, handling the voltage transformation and switching that gets electricity safely to homes, businesses, and industrial facilities. Equipment in this environment is unforgiving of material shortcuts, and PEG Insulating Mounting Board answers several of the requirements that engineers and purchasers look for:
Electrical Isolation: As a dielectric material, our Insulating Mounting Board keeps energized components separated from grounded metal frames and enclosures, reducing the risk of unintended current paths.
Structural Rigidity: The compressed phenolic construction provides excellent rigidity and helps minimize deflection when properly supported.
Dimensional Stability: This material maintains good dimensional stability for many indoor and protected outdoor electrical applications.
Machinability: The material drills, cuts, and routes cleanly, so fabricators can produce precise mounting holes and panel cutouts without cracking or delaminating the sheet.
Long-term Durability: Phenolic laminates are known for holding up under years of continuous service, helping provide a long service life in properly designed electrical applications.
PEG Insulating Mounting Board vs. Alternatives
When specifying an insulating mounting panel for substation and power distribution applications, engineers and purchasers often evaluate several material options based on electrical performance, mechanical strength, flame resistance, and fabrication requirements. While no single material is the right choice for every application, understanding how PEG Insulating Mounting Board compares with other commonly used materials can help ensure the best fit for your project's performance and design requirements.
This comparison isn't intended to rank one material as universally superior. Instead, it highlights where PEG Insulating Mounting Board is best suited.
| Material | Dielectric Performance | Mechanical Strength | Typical Use Case |
|---|---|---|---|
| PEG Insulating Mounting Board | High | High | Structural mounting panels requiring both insulation and load support |
| Standard metal mounting plate | None (conductive) | Very high | Structural support only, requires separate insulating barriers |
| General-purpose polycarbonate | High | Moderate | Enclosure panels, lower structural demand |
| GPO-3 laminate | High | High | Switchgear barriers and insulating components requiring flame resistance |
Ready to get started?
Whether you’re building a new substation or upgrading equipment on an existing one, Piedmont Plastics can help you get the right panel dimensions, thickness, and fabrication for the job. Contact your local branch to get started!
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