Heat Shrink Tubing Voltage Rating
A voltage class belongs to a tested accessory system, not to the name of a material. This page splits the range into four groups (non-rated sleeves, low voltage up to 1 kV, medium voltage cable accessories, and busbar switchgear casings), and shows what each group's rating actually certifies.
How voltage class is decided
For a heat shrink or cold shrink product, the published voltage rating comes from type testing of the complete assembly. The tube or accessory plus the stress control and sealing arrangement it is applied with. Two practical consequences:
- System voltage is not decided by material name. Polyolefin tubing exists in ≤1 kV harness grades and in 26/35 kV accessory systems; silicone rubber appears on both sides too. Naming the polymer does not set the class.
- A thicker or higher-ratio sleeve is not automatically a higher class. Wall construction and tested system design set the rating. Never substitute a general-purpose sleeve into a medium voltage termination because it "looks thicker".
Cable accessories carry dual-number markings such as 0.6/1 kV, 8.7/15 kV, 12/20 kV and 26/35 kV. In this Uo/U notation the first number is the rated power-frequency voltage between conductor and earth and the second is the rated phase-to-phase voltage, so an 8.7/15 kV set is built for a 15 kV-class cable system. Where a product page publishes no electrical class at all, we say so instead of guessing.
General purpose — no electrical class claimed
These sleeves and tapes are specified for temperature, abrasion, bundling or chemical duty. They carry no dielectric rating on their spec sheets and should not be selected as electrical insulation.
Low voltage (≤ 1 kV) — published class
Parts whose pages publish a ≤1 kV (or ≤600 V) rating: harness tubing, sealing tubing and 0.6/1 kV accessory systems tested to IEC 60502.
Medium voltage cable accessories (8.7/15 – 26/35 kV)
Heat shrink and cold shrink termination and joint systems published against named cable classes. The rating certifies the tested accessory system, and each set is applied with the stress control and sealing parts designed for it.
Medium voltage busbar & switchgear casings
Casings shaped for rectangular busbar runs in switchgear, published against busbar test classes rather than cable classes.
Products without a published voltage class
The following accessories are functional sealing or protection parts whose current product pages publish core counts, construction or duty instead of an electrical class. They are grouped here honestly rather than assigned a number they have not been tested against. Tell us the system you are protecting and we confirm the applicable part and documentation.
Frequently asked questions
Does a heat-shrink tube itself have a system voltage rating?
Only the products that carry a published class - the LV harness tubing and the tested cable accessory and busbar systems listed on this page. A general-purpose sleeve has no system voltage rating and cannot be substituted into a rated termination or joint. The rating belongs to the tested accessory system, including its stress control and seal, not to tubing alone.
What information is needed to select MV cable accessories?
The cable system voltage (e.g. 8.7/15, 12/20 or 26/35 kV), conductor size and material, insulation diameter, screen construction, sheath or jacket type, whether the position is a termination or a joint, indoor or outdoor service, and the governing cable standard. Accessory kits are built to cable class and geometry, so send these with your RFQ and we match the set.
How should busbar insulation voltage class be evaluated?
By the tested class of the busbar casing or snap-on product - for example the 8.7/15 kV and 26/35 kV casings on this page - together with the switchgear geometry: busbar width and thickness, phase spacing, creepage and clearance distances, and edge or bend handling. Equipment class comes from the whole designed arrangement, not from tubing material name or wall thickness.