This page covers two UL AWM silicone rubber wire styles available under partner-certified UL AWM manufacturing scope — UL 3135 and UL 3239. Both use silicone rubber insulation and carry a 200°C temperature rating, but they serve fundamentally different electrical functions and must not be treated as interchangeable. Style-specific data should be confirmed against the applicable UL file before quotation.
Certified Specifications — UL Style Reference
| Parameter | UL AWM Style 3135 | UL AWM Style 3239 |
|---|---|---|
| Temperature rating | 200°C | 200°C maximum |
| Voltage rating | 600V AC | Up to 60,000V DC (construction-dependent — confirm per order) |
| 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 (per construction) |
| Min avg insulation thickness | 30 mils (0.76 mm) | Per UL 3239 construction (voltage-rated, confirm per order) |
| Min at any point | 27 mils (0.69 mm) | Per UL 3239 construction |
| Conductor plating | Tinned, silver, or nickel-plated | Tinned, silver, or nickel-plated; may be heat bonded or overcoated |
| Shield / Covering / Jacket | — | Optional (when specified) |
| Flame rating | Horizontal flame | Horizontal flame; VW-1 per applicable construction |
| UL use description | Internal wiring of appliances where totally enclosed | Internal wiring of TV receivers or where acceptability determined by UL |
UL 3135 — 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 by Construction
The DC voltage rating of UL 3239 is construction-dependent. The following grades are indicative; confirm the applicable construction and voltage rating against the UL 3239 style data before ordering.
| DC voltage rating | Selected use example | Insulation construction |
|---|---|---|
| Up to 10,000V DC | HV internal wiring, 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 | HV power supply internal wiring | Multi-layer SR with shield option |
| Up to 60,000V DC | Specialist HV electronic equipment internal wiring | Maximum wall SR + optional jacket |
Selection Guide — UL 3135 vs UL 3239
Choose UL 3135 when:
- Circuit voltage is 600V AC or below
- Application is protected internal wiring of appliances or enclosed equipment
- 200°C temperature rating is required
- AWG 26–12 covers the conductor size requirement
- Bare silicone rubber insulation (no outer braid) is acceptable for the routing
Choose UL 3239 when:
- Circuit voltage exceeds the 600V AC rating of UL 3135
- Application is protected internal HV DC wiring where the applicable UL Style and construction support the requirement
- 200°C temperature rating is required at the HV routing position
- AWG 24–10 (copper/nickel), 12–10 (aluminium), or 27–20 (resistance wire) is needed
- Optional shield, covering, or jacket is required by the equipment design
Application Notes
UL 3135 — appliance and equipment internal wiring
UL 3135 is specified for protected internal wiring in appliances and enclosed equipment where the wire is totally enclosed within the equipment housing. The 200°C / 600V AC rating covers most appliance and equipment internal wiring circuits. AWG 26–12 covers the conductor size range for appliance harness and control wiring applications. Application suitability should be evaluated against the wire rating, routing conditions, and the equipment’s own design evaluation.
UL 3239 — high voltage DC internal wiring
UL 3239 is specified for protected internal high-voltage DC wiring in equipment where the internal DC voltage exceeds the 600V rating of UL 3135. Selected application examples include HV power supply internal leads, high-voltage multiplier stacks, and high-voltage DC internal circuits in electronic equipment. The DC voltage rating is construction-dependent and must be confirmed against the UL 3239 style data for the specific construction ordered. Application suitability should be evaluated by the buyer against the applicable voltage, routing condition, and equipment design.
Ordering Information
For UL 3135: specify AWG, conductor plating (tinned, silver, or nickel), insulation colour, and quantity. For UL 3239: specify the DC voltage rating required, AWG, conductor type (copper, aluminium, or resistance wire), and any optional layers (shield, covering, jacket). Style-specific UL documentation can be provided according to the ordered construction. Both styles available from 100 m minimum order; confirm availability for non-standard sizes at enquiry.
Related UL Styles for Comparison
For braided silicone rubber wire at the same 200°C / 600V rating, see UL 3172 (glass or aramid braid, 26–18 AWG) and UL 3071 (SF-2 braid, 18–13 AWG). For the UL 3239 category page and additional construction details, see UL 3239 High Voltage Silicone Wire.
