UL 3135 and UL 3239 Silicone Rubber High Temperature Appliance Wire
This product page covers two distinct UL AWM silicone rubber wire styles produced at our Yangzhou facility under UL Follow-Up Service File No. E333030 — UL 3135 and UL 3239. While both use silicone rubber as a primary insulation material and share the 200°C temperature rating, they serve fundamentally different electrical functions: UL 3135 is a standard 600V AC single-conductor silicone wire for appliance internal power and control wiring, while UL 3239 is a high voltage DC wire rated to 60,000V DC for internal high voltage circuits in TV receivers, electronic ignition systems, and specialist high voltage assemblies.
Understanding the difference is critical for correct specification — using UL 3135 in a circuit requiring UL 3239’s high voltage rating would result in insulation breakdown and potential equipment damage or fire. This page provides the complete certified specifications for both styles directly from UL Product iQ, allowing engineers and procurement teams to verify and specify the correct style for each application.
Certified Specifications — UL Product iQ Reference
| Parameter | UL AWM Style 3135 | UL AWM Style 3239 |
|---|---|---|
| Temperature rating | 200°C | Maximum 200°C |
| Voltage rating | 600V AC | Up to 60,000V DC |
| Conductor range | 26 AWG – 12 AWG | 24–10 AWG Cu/Ni or 12–10 AWG Al; or 27–20 AWG resistance wire |
| Insulation material | Extruded silicone rubber (SR) | Extruded or non-extruded thermoplastic and/or thermosetting |
| Min avg insulation thickness | 30 mils (0.76 mm) | See facing page (voltage-rated per UL 3239) |
| Min at any point | 27 mils (0.69 mm) | Per UL 3239 facing page |
| Conductor plating | Tinned, silver, or nickel-plated options | Tinned, silver, or nickel-plated; may be heat bonded or overcoated |
| Shield | — | Optional |
| Covering | — | Optional |
| Jacket | — | Optional |
| Flame rating | Horizontal flame | Horizontal flame and VW-1 |
| UL use description | Internal wiring of appliances where totally enclosed | Internal wiring of TV receivers or where acceptability determined by UL |
| UL file number | E333030 | E333030 |
Reprinted from Product iQ with permission from UL Solutions. ©2026 UL LLC. File No. E333030, last updated 2025-12-01.
UL 3135 — Standard 600V Silicone Wire: AWG Reference
| AWG | Nominal cross-section | Approx. OD (mm) | Max resistance (Ω/km at 20°C) |
|---|---|---|---|
| 26 AWG | 0.128 mm² | 2.0 | 134 |
| 24 AWG | 0.205 mm² | 2.2 | 84.2 |
| 22 AWG | 0.325 mm² | 2.5 | 53.5 |
| 20 AWG | 0.519 mm² | 2.8 | 33.6 |
| 18 AWG | 0.823 mm² | 3.2 | 21.4 |
| 16 AWG | 1.31 mm² | 3.8 | 13.3 |
| 14 AWG | 2.08 mm² | 4.4 | 8.45 |
| 12 AWG | 3.31 mm² | 5.2 | 5.21 |
UL 3239 — High Voltage DC Wire: Voltage Ratings
| DC voltage rating | Typical application | Insulation construction |
|---|---|---|
| Up to 10,000V DC | CRT anode supply, EHT circuits | Single or multiple layer SR |
| Up to 20,000V DC | High voltage multiplier circuits | Heavier wall SR insulation |
| Up to 40,000V DC | X-ray equipment HV supply | Multi-layer SR with shield option |
| Up to 60,000V DC | Specialist HV electronic assemblies | Maximum wall SR + optional jacket |
Key Features
UL 3135 — 600V silicone wire
- 200°C / 600V AC — standard appliance internal wiring
- 30 mils SR insulation — verified to UL construction requirements
- Tinned, silver, or nickel-plated conductor options
- Full AWG range 26–12 for harness and appliance wiring
- Horizontal flame — self-extinguishing
- Solder iron resistant — no shrink-back
UL 3239 — HV DC wire
- 200°C / up to 60,000V DC — high voltage DC circuits
- VW-1 and horizontal flame rated
- Extruded or non-extruded insulation options
- Optional shield, covering, and jacket layers
- Aluminium conductor option (12–10 AWG, 90°C max)
- Resistance wire conductor option (27–20 AWG)
- Both styles under File No. E333030 — single supplier for both standard and high voltage silicone wire, simplifying procurement
- Factory-direct from Yangzhou — no intermediary, full traceability from production to delivery
- Custom configurations — non-standard AWG, silver-plated conductor, pre-terminated assemblies available
Common Applications
UL 3135 — appliance and equipment internal wiring
UL 3135 is the most widely specified AWM silicone wire for appliance OEM internal wiring — motor leads, heating element connections, thermostat wiring, and fan motor leads in household and commercial appliances. The “totally enclosed” use description means the wire must be installed inside a housing where it is not exposed to physical contact or direct environmental exposure, covering the majority of appliance internal wiring routes.
UL 3239 — high voltage DC internal wiring
UL 3239 is specified for the high voltage DC wiring in CRT-based displays, plasma generators, HV power supplies, ion generators, and specialist scientific instruments where the internal DC voltage exceeds the 600V rating of any standard AWM wire. The wire must connect the HV transformer secondary to the rectifier, multiplier stack, and final HV output, surviving both the electrical stress of continuous HV DC operation and the thermal environment of the HV supply.
Other applications
- UL 3135: Robot arm internal wiring, servo motor leads, panel wiring in high-ambient-temperature enclosures
- UL 3135: LED driver and power supply internal wiring at elevated ambient temperature
- UL 3239: X-ray and medical imaging equipment HV supply wiring
- UL 3239: Electrostatic precipitator internal HV wiring
- UL 3239: Laser power supply HV internal connections
Ordering Information
For UL 3135: specify AWG, conductor plating (tinned, silver, nickel), insulation colour, and reel length. For UL 3239: specify DC voltage rating required, AWG, conductor type (copper, aluminium, or resistance wire), and required optional layers (shield, covering, jacket). Both styles available from 10 m for sample orders; standard stock in common AWG sizes.
UL 3135 and 3239 compliance documentation available on request. Specify UL style number on purchase order. Contact us for pricing within 24 hours.
Why Choose CableApex
CableApex manufactures both UL 3135 and UL 3239 under UL Follow-Up Service File No. E333030 at our Yangzhou facility. UL 3135 production runs 100% online spark testing at 4 kV; UL 3239 high voltage variants undergo 100% hipot testing at the rated DC voltage plus a safety margin. We supply to appliance OEMs, electronics manufacturers, medical equipment builders, and specialist high voltage equipment companies across more than 40 countries.
