NEMA G10 tube for bus bar support

For bus bar support systems operating under high electrical and mechanical stress, NEMA G10 epoxy fiberglass tube for electrical insulation offers an unmatched balance of rigidity, dielectric strength, and thermal endurance. Bus bar supports must maintain precise phase separation while withstanding short-circuit forces, vibration, and thermal cycling. This material grade uses continuous filament woven glass cloth and a flame-retardant epoxy resin system, making it ideal for isolating copper or aluminum bus bars in switchgear, motor control centers, and power distribution cabinets. Typical dielectric strength exceeds 15 kV/mm, and moisture absorption remains below 0.10% even after 24-hour water immersion. Our G10 FRP tube for high voltage is machined to tight dimensional tolerances, ensuring consistent creepage and clearance distances between phases. The tube’s uniform wall thickness prevents localized stress concentration and eliminates weak points that can lead to tracking or flashover in high-voltage assemblies. As a dedicated epoxy fiberglass tubing NEMA grade supplier, we verify each production lot for dielectric breakdown voltage, moisture absorption, and compressive strength before shipment. Every tube we ship is backed by full traceability from a certified NEMA G10 tube manufacturer with in-house testing capabilities. This combination of material purity, dimensional accuracy, and batch-level documentation makes the tubing suitable for both OEM production and field retrofit projects.

The NEMA G10 tube for bus bar support is engineered for long-term reliability in demanding electrical enclosures. It resists cracking under torque, prevents tracking across insulation surfaces, and maintains its mechanical properties at elevated temperatures. Standard tubes are produced by wrapping epoxy-impregnated glass cloth around a precision mandrel, followed by oven curing and centerless grinding to achieve a smooth internal bore. This process yields excellent concentricity and allows the tube to slide over threaded rod or bus bar studs without binding. The cured epoxy matrix provides excellent resistance to transformer oil, mild acids, and alkaline cleaning agents, which is critical in substation and industrial environments. The following specifications apply to standard tubing used for bus bar supports.

Key material and electrical properties:

• Material: Woven glass cloth reinforced epoxy resin laminate (NEMA G10 / FR-4 base)
• Continuous operating temperature: 130°C (Class B), short-term peak 180°C
• Flame rating: UL94 V-0 available on request
• Moisture absorption: ≤ 0.10% (24 h immersion, ASTM D570)
• Dielectric strength: 14–16 kV/mm short-time, perpendicular to laminate
• Insulation resistance: > 1 × 10⁶ MΩ at 500 VDC
• Standard lengths: 300 mm, 600 mm, 1000 mm, 1200 mm; custom lengths available

Typical dimensional tolerances:

• Inside diameter tolerance: ±0.05 mm for sizes up to 20 mm; ±0.08 mm for larger sizes
• Outside diameter tolerance: ±0.10 mm
• Wall thickness variation: ≤ 0.05 mm
• Length tolerance: ±0.5 mm on standard cut lengths

Dimensional and mechanical parameters:

Common bus bar support sizes:

• ID × OD: 10 mm × 16 mm
• ID × OD: 12 mm × 20 mm
• ID × OD: 16 mm × 25 mm
• ID × OD: 20 mm × 30 mm
• ID × OD: 25 mm × 38 mm
• Custom diameters and wall thicknesses available upon request

For applications requiring enhanced flame retardance, UL94 V-0 rated material is available on request. Tubes can also be supplied with chamfered ends, drilled cross holes, or threaded inserts to simplify bus bar assembly. All machined features are performed in-house to maintain dimensional integrity and avoid micro-cracking at cut edges.