Composite Insulator
- Silicone-rubber composite long-rod insulator — light, unbreakable, hydrophobic
- Fibreglass core rod with moulded silicone sheds
- For suspension, tension and post applications 11 kV–500 kV
- Far lighter than porcelain; vandal- and shock-resistant
- Hydrophobic surface resists pollution flashover
- End fittings to IEC 60120 ball / socket / clevis / tongue
Technical Specifications
| Catalog | Type | System kV | SML (kN) | Creepage (mm) | End Fitting |
|---|---|---|---|---|---|
| RAX-CI-24 | Suspension | 24 | 70 | 750 | Ball / socket |
| RAX-CI-66 | Suspension | 66 | 100 | 1950 | Ball / socket |
| RAX-CI-132 | Tension | 132 | 120 | 3650 | Clevis / tongue |
| RAX-CI-220 | Tension | 220 | 160 | 6100 | Clevis / tongue |
| RAX-CI-500 | Tension | 500 | 210 | 13900 | Clevis / tongue |
| Custom | Other voltages / SML / end fittings — send your line spec | ||||
Application & Installation
Where it is used
The composite (silicone-rubber) insulator uses a fibreglass core rod for strength and moulded silicone sheds for insulation. It is a fraction of the weight of an equivalent porcelain string, will not shatter, and its hydrophobic surface resists pollution flashover — used for suspension, tension and post duty from distribution to EHV.
Installation sequence
- Select the type (suspension / tension), voltage and SML.
- Confirm the end fittings match your string (ball / socket / clevis).
- Couple the insulator into the string or mount the post.
- Fit a corona / grading ring above 230 kV.
- Hang the clamp at the conductor end.
Buyer’s Guide: Composite Insulator
1. What a Composite Insulator Is
A composite insulator is a fibreglass core rod carrying the mechanical load, over-moulded with silicone-rubber sheds that do the insulating. It replaces a porcelain or glass string with a single light, slim rod — the modern choice where weight, breakage or pollution are concerns.
2. Why Composite Over Porcelain
It weighs a fraction of an equivalent porcelain string, cannot shatter under impact or gunshot, and its hydrophobic silicone surface sheds water so pollution layers do not form a conductive film. That means fewer flashovers in dirty or coastal air and easier handling.
3. SML & Voltage
Rated by Specified Mechanical Load (SML, 70–210 kN) and system voltage (11–500 kV). Creepage is set by the shed count and rises steeply with voltage — pick both for the line.
4. Suspension vs Tension vs Post
Suspension and tension types differ in end fittings (ball / socket for suspension, clevis / tongue for tension dead-ends); post types are rigid for line-post duty. Specify the application so the fittings match.
5. Corona Rings
Above ~230 kV a corona / grading ring is fitted at the line end (both ends above 500 kV) to grade the field and protect the end seal — we supply the matching ring.
6. End Fittings
Forged steel end fittings to IEC 60120 (16 / 20 / 24 mm) let the insulator couple with our ball / socket clevis, yoke and clamps. Specify the coupling so the string mates.
