26/35KV Power Bus-Bar Heat Shrinkable Protective Casing MPG35
26/35KV Power Bus-Bar Heat Shrinkable Protective Casing MPG35 is built from Polyolefin (cross-linked PE). It ships expanded and recovers to a tight, conforming fit once you apply heat (hot-air gun, 150–250 °C). On the shelf it is held to working range -55℃~+125℃, rated for 26/35KV. Buyers spec it for HV distribution busbar insulation — the typical call is a sized part that stays put through vibration, thermal cycling and field handling. Below is the spec table, the size matrix we keep in stock, and the selection notes our engineering team uses when a purchaser sends a cable or component drawing.
Specification
| Material | Polyolefin (cross-linked PE) |
|---|---|
| Operating temperature | -55℃~+125℃ |
| Voltage rating | 26/35KV |
| Wall type | Thick wall |
| Colors | Red / yellow / green |
| Standards | ASTM D2671 |
| Size range | ID Φ30~Φ200mm |
What it is and how it recovers
26/35KV Power Bus-Bar Heat Shrinkable Protective Casing MPG35 starts as an expanded tube. The expansion is locked in by cross-linking, so it holds the large diameter until heat is applied and it recovers toward its extruded size. Because the body is Polyolefin (cross-linked PE), the recovered wall keeps its dielectric strength and mechanical protection after cooling — it does not relax back. For procurement this matters: the part you receive is reusable on the bench, but once installed it stays put for the life of the assembly.
Where 26/35KV Power Bus-Bar Heat Shrinkable Protective Casing MPG35 is used
Primary applications: HV distribution busbar insulation.
How to select the right size
Specifying 26/35KV Power Bus-Bar Heat Shrinkable Protective Casing MPG35 is mostly about matching three numbers to the part you are covering:
- Supplied vs. recovered diameter. The sleeve must slide over the largest feature (connector, lug, splice) and recover snugly on the smallest. Send us the largest and smallest OD and we return the exact part number.
- Temperature class. The continuous range is -55℃~+125℃. If the assembly sees brief excursions beyond that, tell us — we will flag a high-temp grade instead of letting the wall soften in service.
- Voltage rating. This item is rated 26/35KV. Do not substitute a low-voltage sleeve on a medium-voltage joint; the wall thickness and tracking resistance are different by design.
- Wall and adhesive. Thin wall for tight harness bundles; medium/thick wall or adhesive-lined (dual-wall) where you need environmental sealing or abrasion resistance. We keep both in stock.
Common Failure Modes & How to Prevent Them
Drawing on field reports and our engineering team's experience, these are the most common issues installers and buyers report when working with 26/35KV Power Bus-Bar Heat Shrinkable Protective Casing MPG35. Each entry shows the symptom, the root cause, and the fix we recommend on the bench and in the field.
It cracked along the axis near the busbar
Same failure mode seen on harnesses shows up on busbar casing too: "every single piece had cracked along the longitudinal axis" when the material couldn't take the heat.
Root cause: Busbar joints run warm, and a casing rated below the operating temperature degrades. A thin or low-grade wall also loses creepage distance under load.
Fix: Spec a cross-linked polyolefin casing matched to the busbar's continuous temperature and voltage class. Keep the wall thick enough for the required creepage and clearance, and confirm the rating on the datasheet before install.
Touch-safe coverage came up short
On site, crews find the casing "doesn't fully cover the joint - fingers could still reach a live part."
Root cause: The tube was cut to the bare joint and shortened on recovery, leaving the edge exposed.
Fix: Size for recovery shrinkage (5-15%) and extend the casing well past both joint faces. For switchgear, the goal is finger-safe coverage plus the rated creepage distance, not just a tidy look.
Tracking marks appeared in a damp, dirty cabinet
"After a season in a humid panel, we saw carbon tracking on the surface."
Root cause: Dust and moisture on an untreated surface let surface leakage current track and carbonise.
Fix: Use an anti-tracking grade and keep the busbar enclosure clean and dry. Where the environment is harsh, add the rated creepage distance rather than relying on a thin cover.
Two batches looked like two different colours
A maintenance lead noted: "the high-voltage and low-voltage busbar casing didn't match in colour between batches."
Root cause: Colour comes from masterbatch and raw-batch variation; it is cosmetic but it causes field confusion.
Fix: Hold one approved colour per voltage class and buy to a single batch where possible. Colour should signal voltage, so keep it consistent across the installed base.
Shrinking next to live busbar felt risky
Crews are wary: "heating a sleeve a few centimetres from an energised bar is not comfortable."
Root cause: Heat guns near live parts are a real hazard if the work is not isolated.
Fix: De-energise and bond before recovery wherever the schedule allows. If live work is unavoidable, use trained crews, rated tools, and keep the heat source clear of conductors.
Common Failure Modes & How to Prevent Them
Drawing on field reports and our engineering team's experience, these are the most common issues installers and buyers report when working with 26/35KV Power Bus-Bar Heat Shrinkable Protective Casing MPG35. Each entry shows the symptom, the root cause, and the fix we recommend on the bench and in the field.
It cracked along the axis near the busbar
Same failure mode seen on harnesses shows up on busbar casing too: "every single piece had cracked along the longitudinal axis" when the material couldn't take the heat.
Root cause: Busbar joints run warm, and a casing rated below the operating temperature degrades. A thin or low-grade wall also loses creepage distance under load.
Fix: Spec a cross-linked polyolefin casing matched to the busbar's continuous temperature and voltage class. Keep the wall thick enough for the required creepage and clearance, and confirm the rating on the datasheet before install.
Touch-safe coverage came up short
On site, crews find the casing "doesn't fully cover the joint - fingers could still reach a live part."
Root cause: The tube was cut to the bare joint and shortened on recovery, leaving the edge exposed.
Fix: Size for recovery shrinkage (5-15%) and extend the casing well past both joint faces. For switchgear, the goal is finger-safe coverage plus the rated creepage distance, not just a tidy look.
Tracking marks appeared in a damp, dirty cabinet
"After a season in a humid panel, we saw carbon tracking on the surface."
Root cause: Dust and moisture on an untreated surface let surface leakage current track and carbonise.
Fix: Use an anti-tracking grade and keep the busbar enclosure clean and dry. Where the environment is harsh, add the rated creepage distance rather than relying on a thin cover.
Two batches looked like two different colours
A maintenance lead noted: "the high-voltage and low-voltage busbar casing didn't match in colour between batches."
Root cause: Colour comes from masterbatch and raw-batch variation; it is cosmetic but it causes field confusion.
Fix: Hold one approved colour per voltage class and buy to a single batch where possible. Colour should signal voltage, so keep it consistent across the installed base.
Shrinking next to live busbar felt risky
Crews are wary: "heating a sleeve a few centimetres from an energised bar is not comfortable."
Root cause: Heat guns near live parts are a real hazard if the work is not isolated.
Fix: De-energise and bond before recovery wherever the schedule allows. If live work is unavoidable, use trained crews, rated tools, and keep the heat source clear of conductors.
Frequently asked questions
Can it insulate a 26/35 kV busbar that has bolted joints and bends?
Yes. The cross-linked PE recovers tightly around straight runs, 90° bends and bolted connections without splitting, keeping its dielectric wall after cooling. Best practice is to slide the casing over the bar before the final bolt-up; if the joint is already assembled, choose an ID that clears the bolt head and recover with a hot-air gun working from the centre outward to avoid trapped air.
What dielectric strength and tracking resistance does it give at 35 kV?
The thick-wall cross-linked PE is rated for 26/35 kV service and is formulated as anti-tracking / anti-corona to suppress surface creepage and partial discharge on polluted insulators. For your specific creepage-distance and withstanding-voltage requirement, send the busbar spacing and we confirm the wall thickness and length needed.
Do you supply phase-identification colours?
Yes — MPG35 is available in red, yellow and green to match the IEC phase-colour code, and we can kit a three-phase run as a matched set so field crews install the right sleeve on each phase without mix-ups.
Can it be installed on a busbar that is already in place?
For field retrofits, use a pre-expanded length sized to slip over the bar end or through a disconnect point, then recover with a hot-air gun (150–250 °C) from the middle outward. Because the wall is thick, allow extra heat and time versus thin-wall tubing and support long spans so the softened casing does not sag.
Is it suitable for outdoor substations — UV, weather and pollution?
The cross-linked polyolefin resists weathering, UV and surface tracking under wet or polluted outdoor conditions, which is why it is used on HV distribution busbars in substations. For coastal or heavy-industrial pollution, tell us the pollution level (IEC 60815) and we specify the appropriate wall and colour.
What sizes and lengths can you supply, and do you have IEC / EN certification for EU tenders?
Standard IDs run Φ30–Φ200 mm and lengths are cut to your bar dimensions; larger IDs and custom walls are available on request. The product is built to ASTM D2671; for European grid tenders we can align documentation to IEC/EN equivalents and issue certificates per batch — name the standard your tender requires.
What rating do I need for a busbar casing?
Match the casing to the busbar's continuous temperature and voltage class, with wall thick enough for the required creepage and clearance.
How do I make a busbar joint finger-safe?
Size for recovery shrinkage and extend the casing well past both joint faces so no live part is reachable, while keeping the rated creepage distance.
Why did tracking appear on the surface?
Dust and moisture on an untreated surface let leakage current track. Use an anti-tracking grade and keep the enclosure clean and dry.
Can busbar casing colours differ between batches?
They can, from masterbatch and raw-batch variation. Hold one approved colour per voltage class and buy to a single batch where possible.
Request a quote for 26/35KV Power Bus-Bar Heat Shrinkable Protective Casing MPG35
Tell us the inner diameter, wall type, length and quantity you need, plus the voltage class and environment. We return a sized part number, stock status and lead time — no price guessing, no minimum-order surprises.
Certifications & Compliance
26/35KV Power Bus-Bar Heat Shrinkable Protective Casing MPG35 is built to the following standards and directives. Certificates are supplied per batch on request.
Tell us your target market (EU / US / Asia) and we align the documentation to your filing.
Size range & specification notes
内径Φ30~Φ200mm