Written by the GOTO Electrical Technical Team · 11 years of arrester manufacturing · Products type-tested to IEC 60099-4
A polymer surge arrester uses a silicone-rubber housing around gapless zinc-oxide (ZnO) varistor blocks, while a traditional lightning arrester uses a porcelain or ceramic housing, historically built with silicon-carbide blocks and series spark gaps. In practical procurement terms, the polymer design is far lighter, will not shatter under fault energy, and performs better in polluted or coastal environments; the porcelain design still offers proven mechanical rigidity and an extremely long outdoor track record. This guide compares both types across housing material, weight, failure mode, pollution performance, service life and total cost, so utility, EPC and OEM buyers can specify the right overvoltage protection for 3 kV to 36 kV distribution networks.
A polymer surge arrester is a gapless metal-oxide arrester whose ZnO varistor column is bonded inside a silicone-rubber housing with moulded sheds. Because silicone rubber is hydrophobic, water beads and runs off instead of forming a conductive film, which keeps leakage current low even in salt fog or industrial pollution. The housing is also flexible, so the unit survives impact, transport vibration and thermal shock without cracking.
GOTO supplies polymer-housed units for medium-voltage systems to 36 kV, built and tested to IEC 60099-4. Typical ratings are:
● System application voltage: 3 kV to 36 kV
● Nominal discharge current: 5 kA or 10 kA, Class 1
● High-current withstand: 65 kA (5 kA class) or 100 kA (10 kA class)
● Rated arrester voltage Ur: 3 kV to 48 kV
● Creepage distance: 195 mm up to about 1,116 mm depending on pollution class
● Leakage current at 0.75 × U1mA: under 50 µA
The varistor stack is the active element. Every MOV block receives electrical routine tests for reference voltage, discharge voltage, leakage current, thermal stability and ageing before assembly, and each finished arrester is checked for partial discharge at 1.05 × Uc (10 pC or less). You can review the full ratings in our polymer surge arrester product range.
Cross-section of a polymeric ZnO arrester: silicone-rubber sheds, MOV varistor column and sealing system.
The term “lightning arrester” predates modern metal-oxide technology. Early designs used silicon-carbide (SiC) blocks in series with spark gaps, housed in glazed porcelain. The porcelain gave excellent mechanical strength and UV stability, but the SiC gap design could only limit switching surges partly, and the gap had to reseal after every discharge.
Later generations moved to gapless ZnO blocks but kept the porcelain housing. So a “traditional lightning arrester” bought today is usually a porcelain-housed gapless arrester. Its defining traits are:
● Porcelain or ceramic housing with cemented metal end fittings
● High compressive strength and excellent resistance to UV and tracking
● Significantly heavier, typically two to three times a polymer unit of the same rating
● Brittle behaviour: chipping, cracking or shattering if struck or dropped
● Requires careful handling, dedicated lifting and trained installation crews
The table below summarises the comparison most buyers need when they move from a porcelain specification to a polymer one.
| Factor | Polymer Surge Arrester | Traditional Lightning Arrester |
|---|---|---|
| Housing material | Silicone rubber with moulded sheds | Glazed porcelain or ceramic |
| Weight | Light, typically 40–60% lighter | Heavy, two to three times heavier |
| Impact resistance | Flexible, resists drops and vandalism | Brittle, chips and cracks on impact |
| Failure mode | Pressure-relief venting, no shrapnel | Can shatter or burst under fault energy |
| Pollution and coastal duty | Hydrophobic, low leakage in salt fog | Wetting film forms, periodic washing needed |
| Installation | One-person handling, lighter brackets | Two-person crew, lifting equipment |
| Standards | IEC 60099-4, IEEE C62.11, GB 11032 | IEC 60099-4, IEEE C62.11, GB 11032 |
Silicone rubber is a polymer whose surface stays hydrophobic and even transfers that property to pollution deposited on it. Porcelain is a ceramic: when its glaze is clean it performs well, but a dirty or salted glaze becomes hydrophilic and leakage current rises, which is why porcelain units in coastal or heavy-industrial zones often need washing. Our detailed polymeric vs porcelain surge arrester comparison covers this trade-off further.
Weight is the most immediate saving on site. A polymer unit can often be carried and mounted by one technician, while an equivalent porcelain arrester needs two people and sometimes a hoist. Lighter arresters also let you use lighter cross-arm brackets and reduce transport cost per container, which matters when a project ships hundreds of units.
This is the strongest safety argument for polymer. If a porcelain arrester absorbs more energy than it can dissipate, the housing can burst and throw ceramic fragments, endangering crews and damaging nearby equipment. A polymer-housed arrester fails by venting pressurised gas through a designed relief path, with the housing staying largely intact. For that reason many utilities now specify polymer housings for distribution-class arresters mounted near public areas. Where live-line replacement matters, a drop out surge arrester adds a disengaging device that drops the failed unit clear of the line.
Operating principle of a gapless polymer surge arrester to IEC 60099-4: ZnO varistors clamp the surge and restore insulation.
For coastal, desert or heavy-industrial sites, specify creepage distance rather than just voltage. Our 36 kV polymer units offer 900 mm to 1,116 mm of creepage, and 33 kV units 825 mm to 1,023 mm. Silicone rubber also resists UV and tracking; over decades it may chalk or lose a little hydrophobicity, but it recovers that property during wet periods. Porcelain glaze is very UV stable, though its cemented joints and seals remain the usual moisture-ingress path.
Both technologies reach 20 to 30 years when correctly rated for the system. The difference shows up in operating cost. A polymer arrester needs little more than an annual visual inspection and leakage-current trend check; a porcelain arrester in a polluted area may also need outage time for washing. Fit a surge counter or a disconnector and you can spot end-of-life without pulling the unit. When you add avoided wash outages, lighter logistics and fewer breakages in transit, polymer usually wins on total cost even where unit price is similar.
GOTO Electrical supplies IEC 60099-4 polymer surge arresters from 3 kV to 36 kV for utilities, EPC contractors and OEMs. Send us your system voltage, earthing arrangement and pollution level, and our engineering team will return a matched specification with factory-direct pricing.
Polymer is not universally better. A porcelain-housed arrester remains a sound choice in these situations:
● Existing switchgear or substation structures already dimensioned for porcelain units
● Very high mechanical loading, such as long cantilever-mounted terminal connections
● Sites with severe abrasion from sand or where vandalism damage to rubber is a concern
● Utility standards or tender documents that explicitly specify ceramic housings
● Clean inland substations where pollution performance is not a deciding factor
Use this checklist before you issue a specification. Print it and work through it with your design team.
☐ Confirm system voltage and maximum continuous operating voltage (MCOV) for the earthing arrangement
☐ Select discharge class: 5 kA for standard distribution duty, 10 kA for higher-exposure lines
☐ Set creepage distance from the site pollution class, not from voltage alone
☐ Check residual voltage against the insulation withstand (BIL) of the protected equipment
☐ Decide whether you need a disconnector, surge counter or remote monitoring
☐ Confirm mounting bracket, terminal type and creepage with the existing structure
☐ Verify the supplier holds current type-test reports to IEC 60099-4
Our guide to selecting the right polymeric surge arrester walks through each step in more detail, and you can browse the complete metal oxide surge arrester range for 3 kV to 220 kV classes.
Not exactly. “Lightning arrester” is the older term for any overvoltage protector; a polymer surge arrester is a modern gapless ZnO arrester with a silicone-rubber housing.
Both reach 20 to 30 years when correctly rated. Porcelain resists UV slightly better, but polymer survives pollution, impact and thermal shock better, so field life is usually similar.
Usually yes, provided rated voltage Ur, MCOV, discharge class and creepage match or exceed the original. Always confirm the mounting bracket and terminal type first.
Yes. Silicone rubber is hydrophobic and resists salt fog. Specify longer creepage, such as 900 to 1,116 mm for 36 kV, in coastal or heavy industrial zones.
IEC 60099-4 is the core standard for gapless metal-oxide arresters. IEEE C62.11 applies in North America and GB 11032 in China.
Very little. Inspect housings annually, trend leakage current, and fit a surge counter or disconnector to flag end of life without an outage.
GOTO polymer units cover 3 kV to 36 kV system voltage, with 5 kA and 10 kA discharge classes and 65 kA or 100 kA high-current withstand.
Tell us your system voltage, earthing arrangement and site pollution level. GOTO Electrical will return a polymer or porcelain specification, type-test documentation and factory-direct pricing within one business day.
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