Busbar Insulation Tubing: Sizing Guide

Busbar and switchgear insulation must clear the bar cross-section, withstand the system voltage, and stay put through thermal cycling. Here is how to spec it.

Clear the busbar cross-section

Measure the bar width and thickness, then add the bend radius. Supplied ID must slide over the widest point; recovered ID grips the bar. We keep 8.7/15 kV busbar casing (MPG10) from Φ20 mm up to Φ180 mm, single and three-core formats.

Match the voltage rating

For 8.7/15 kV distribution use the MPG10 medium-heavy wall grade. For 26/35 kV networks step up to MPG35 casing with the thicker wall and tracking resistance the class demands. Do not substitute an LV sleeve on an MV bar.

Phase colour and marking

Casings come in red / yellow / green / black for phase identification. Tell us the cabinet layout and we supply the cut lengths and colour mix per phase.

Where it is used

Distribution cabinet busbar, switchgear copper-bar protection and phase separation. See busbar solutions for the full product set.

Quick sizing checklist

1. Measure the bar width and thickness, then add the bend radius.
2. Confirm the supplied ID slides over the widest point and the recovered ID grips the bar.
3. Match the voltage class: MPG10 for 8.7/15 kV, MPG35 for 26/35 kV.
4. Choose the phase colour (red, yellow, green, black) to your cabinet convention.
5. Send the cabinet layout so cut lengths and the colour mix per phase come back correct.

Frequently asked questions