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High Temperature Cables

UL 3257 Silicone Ignition Wire, 250°C 10kV AC / 25kV DC

UL 3257 is a UL-certified silicone ignition wire rated 250°C, 10 kV AC and 25 kV DC. The stranded nickel-plated copper construction is intended for internal high-voltage leads, with separate voltage ratings for AC and DC circuits.

  • Voltage: 10 kV AC / 25 kV DC
  • Temperature: 250°C
  • Insulation / covering: extruded silicone rubber
  • Size selection: 22–12 AWG
  • Certification: UL-certified AWM; UL 758
Product information
Product overview

UL 3257 wire selection

UL 3257 is a UL-certified silicone ignition wire rated 250°C, 10 kV AC and 25 kV DC. The stranded nickel-plated copper construction is intended for internal high-voltage leads, with separate voltage ratings for AC and DC circuits.

Two silicone wall options are listed across 22–12 AWG: 5/64 in and 7/64 in. The larger wall increases the finished diameter, weight and minimum bend radius even when the conductor size stays the same. The two complete tables make that difference visible, so an ignition lead can be selected against the terminal boot, entry opening and available bend space rather than by AWG alone.

For burner or oven ignition assemblies, record the waveform and operating voltage before choosing the construction. Protect the lead from repeated flexing and use terminations that suit the full voltage and temperature duty. The silicone construction is not intended for immersion. Where a thicker wall is requested, make sure the assembly drawing also allows the larger outside diameter and bend radius.

See the Specifications tab for the model and size tables. Browse the high-temperature cable range for related constructions. Compare the construction of high-voltage silicone wire when the duty is a high-voltage equipment lead rather than an igniter.

Construction

Construction

UL 3257 uses the following conductor and insulation system. The diagram illustrates the layer sequence; select the conductor construction and covering shown in the required size specification.

Illustrative UL 3257 single-core conductor and insulation construction cutaway
Illustrative UL 3257 construction; layer dimensions are not to scale.
UL 3257 construction layers
ComponentConstruction detail
ConductorStranded 2% nickel-plated copper
InsulationExtruded silicone rubber
Wall options5/64 in standard or 7/64 in thicker wall
Applications

Applications

UL 3257 suits internal ignition and high-voltage lead connections in burners, ovens and related equipment. The wire must be installed without flexing in service, with terminal insulation and clearances appropriate to the circuit.

Illustrative UL 3257 insulated lead routed inside industrial equipment
Illustrative UL 3257 equipment application; shown as an installation concept.

UL 3257 replacement selection

For replacement enquiries, include the existing wire marking and the equipment connection drawing so the conductor, insulation and terminal arrangement can be matched.

Specifications

Specifications

UL 3257 technical data
ParameterSpecification
UL styleUL 3257
Voltage rating10 kV AC / 25 kV DC
Temperature rating250°C
Insulation / coveringextruded silicone rubber
Conductor size coverage22–12 AWG
AC voltage rating10,000 V AC
DC voltage rating25,000 V DC
Minimum average / point silicone wall78 / 70 mils
Temperature range in supplied construction−60°C to 250°C
InstallationInternal wiring without flexing; not for immersion
UL 3257 5/64 in wall dimensions
Model, size and silicone wallStrandsOD (mm)OD (in)Weight (kg/km)Weight (lb/1000 ft)Min. bend radius (in)
UL 3257 22 AWG — 5/64 in74.830.19026.52181.52
UL 3257 20 AWG — 5/64 in75.000.19729.41201.58
UL 3257 18 AWG — 5/64 in195.180.20433.38221.63
UL 3257 16 AWG — 5/64 in265.510.21740.73271.74
UL 3257 14 AWG — 5/64 in415.890.23250.85341.86
UL 3257 12 AWG — 5/64 in656.350.25066.58452.00
UL 3257 7/64 in wall dimensions
Model, size and silicone wallStrandsOD (mm)OD (in)Weight (kg/km)Weight (lb/1000 ft)Min. bend radius (in)
UL 3257 22 AWG — 7/64 in76.450.25445.26302.03
UL 3257 20 AWG — 7/64 in76.630.26148.70332.09
UL 3257 18 AWG — 7/64 in196.810.26853.26362.14
UL 3257 16 AWG — 7/64 in267.140.28161.69412.25
UL 3257 14 AWG — 7/64 in417.520.29673.09492.37
UL 3257 12 AWG — 7/64 in657.980.31490.40612.51

Selecting the specified construction

Use UL 3257 plus AWG and wall option on the order. State 10 kV AC or 25 kV DC duty explicitly and compare the corresponding OD and minimum bend radius before choosing a boot or gland.

Standards

Standards

TEBAOFLEX UL 3257 wire is UL-certified appliance wiring material.

UL 3257 certification and standards
ItemRequirement or reference
CertificationUL-certified AWM
Style designationUL 3257
Construction standardUL 758 — Appliance Wiring Material
Style flame classificationHorizontal flame

Identify the UL style, conductor size, voltage and temperature grade on the purchasing specification. Include the required product identification and certification documents with the enquiry.

Engineering-led quotation

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