GPO-3 Polyester Glass Laminate Sheet
Track-resistant, V-0 sheet for busbar supports and barriers. GPO-3 is the standard sheet for busbar supports and switchgear barriers because of its track resistance and V-0 flame class. We hold it in stock and machine to drawing. Plates are cut, punched burr-free and machined with hole position and flatness inspected.
Technical specifications
| Material | Polyester glass (GPO-3) |
| Temp class | F, ~155 degC |
| Flame | UL 94 V-0 |
| Property | High track resistance |
| Use | Busbar supports, barriers |
💾 Datasheets & Test Reports
Download the technical data sheet for this product (PDF).
Applications by industry
- Busbar supports and phase barriers in MV switchgear
- Arc-shielding plates in MCC buckets and breaker compartments
- Motor control center insulation sheets
- Transformer saddle and clamp assembly plates
- Low-CTI supports in panel and box manufacturing
- Punchable, arc-resistive laminate for OEM enclosures
Why GPO-3 polyester glass for this application
GPO-3 punches cleanly, arcs well and keeps a high CTI, making it the standard flat stock for MV bus supports and barrier plates where tracking in polluted air is the real enemy.
Confirm CTI/tracking index for your application voltage; GPO-3 is not for continuous high-load structural use. Check punch-vs-fill interplay for thin sections.
Standards:ASTM D709, IEC 60893, UL 94 V-0, UL 1446 (grade dependent).
Feature and remaining-wall review
GPO-3 Polyester Glass Laminate Sheet is machined with diamond-coated tooling for clean edges, then CNC turned, ground and drilled to drawing. With moisture content controlled, dimensional stability holds. Feature depth, edge distance and remaining wall are checked against the critical geometries, and capability is confirmed on your drawing rather than a blanket tolerance.
Inspection and traceability
We state the control plan with you. Batch traceability links raw material lot to finished part.
- First-article inspection (FAI) per your plan
- In-process dimensional checks at every station
- Batch certificate of conformance (COA) supplied on request
- Lot traceability to incoming material certificate
- Dielectric strength and insulation resistance testing available on request
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Common questions
Why use GPO-3 for busbar supports and barriers?
Polyester glass holds a high CTI and burns to UL 94 V-0 without dripping, so it resists tracking and surface leakage along busbars. It machines cleanly into supports, spacers and partitions.
What is the difference between GPO-3 and FR-4?
GPO-3 is polyester-bonded fiberglass; FR-4 is epoxy-bonded. FR-4 has a higher temperature rating and moisture resistance; GPO-3 has better flame retardancy and low-smoke behaviour. Pick FR-4 where continuous heat drives, GPO-3 where tracking and fire rating lead.
Can GPO-3 be machined to tight tolerances?
Yes. CNC milling and punching cut burr-free to ±0.1 mm, but the resin wears tools and throws dust, we run extraction and keep tooling sharp. For thin sections check remaining-wall and edge distance before punching.
Is GPO-3 arc-resistant?
It has good arc resistance and high CTI, suitable for arc-shielding and barrier parts. It is not arc-quenching; for the fuse tube itself use a vulcanized fiber composite.
What certifications do you provide?
Material COA with batch traceability, first-article inspection per your plan, and RoHS/REACH compliance on request. UL 94 V-0 and CTI certification available per grade.
Engineering Guides & Selection Notes
Engineering notes covering the sizing and specification questions around GPO-3 Polyester Glass Laminate Sheet.
Get pricing for GPO-3 Polyester Glass Laminate Sheet
For GPO-3 Polyester Glass Laminate Sheet, attach the drawing plus the annual volume. Material, tolerance, ID, OD, wall and features all get checked against it before we quote, and the manufacturability notes for GPO-3 Polyester Glass Laminate Sheet come with the price.