UL 3223 silicone wire is a single-core, 300 V high-temperature hook-up wire for protected internal equipment wiring at temperatures up to 150°C. The reference construction combines a solid or stranded copper conductor with SR silicone rubber insulation. The documented stranded series spans 4/0 AWG through 30 AWG, using a 1.58 mm insulation thickness and finished diameters selected for each conductor size.
TEBAOFLEX can manufacture this construction to an approved project specification and can review conductor size, strand design, insulation colour, printing, cut length, coil or reel length and packaging. The final conductor, dimensions, electrical loading, installation conditions and required production documents are confirmed before quotation.
UL 3223 Silicone Wire at a Glance
| Selection point | Reference specification |
|---|---|
| Product type | Single-core silicone insulated high-temperature hook-up wire |
| Model reference | UL 3223 |
| Rated voltage | 300 V |
| Rated temperature | Up to 150°C |
| Conductor | Copper; solid or stranded according to the confirmed construction |
| Insulation | SR silicone rubber |
| Reference size range | 4/0 AWG to 30 AWG |
| Reference insulation thickness | 1.58 mm |
| Reference bend radius | 10 × finished outer diameter |
What Is UL 3223 High Temperature Wire?
UL 3223 wire is a heat-resistant single-conductor wiring construction that uses silicone rubber as the electrical insulation. It is commonly searched as 300V silicone wire, 150°C hook-up wire, SR silicone wire, high temperature appliance wire, heater lead wire or silicone insulated copper wire. These terms describe a purchasing need rather than universal interchangeability. The exact conductor size, strand design, outside diameter, termination method and installation environment must match the equipment drawing. This page uses the 3223 designation as the product model reference and does not make a blanket statement about project-specific marking or documentation.
How Is the 300V Silicone Wire Constructed?
| Component | Reference construction | Selection relevance |
|---|---|---|
| Conductor | Copper, solid or stranded | The strand design affects flexibility, termination compatibility, conductor diameter and finished wire size. |
| Primary insulation | SR silicone rubber | Provides the electrical insulation and thermal capability for the confirmed 150°C construction. |
| Core count | Single core | Intended as an individual internal lead rather than a multi-core power or control cable. |
| Insulation wall | 1.58 mm in the documented series | Used with the conductor dimensions below to determine the finished outside diameter. |
4/0–30 AWG Reference Size and Diameter Table
The table reproduces the full stranded-conductor dimensional series in the supplied technical material. Values apply to that reference construction. A different strand design, conductor material tolerance, colour compound or customer specification can change the conductor diameter and finished outside diameter, so production dimensions must be confirmed on the approved data sheet.
| AWG | Stranding (No./mm) | Conductor diameter (mm) | Insulation thickness (mm) | Finished OD (mm) |
|---|---|---|---|---|
| 4/0 | 2146/0.254 | 15.70 | 1.58 | 16.76 ± 0.15 |
| 3/0 | 1615/0.254 | 13.65 | 1.58 | 14.96 ± 0.15 |
| 2/0 | 1330/0.254 | 12.36 | 1.58 | 13.87 ± 0.15 |
| 1/0 | 1026/0.254 | 10.85 | 1.58 | 12.57 ± 0.15 |
| 2 | 665/0.254 | 8.74 | 1.58 | 10.73 ± 0.15 |
| 4 | 420/0.254 | 6.94 | 1.58 | 9.18 ± 0.15 |
| 6 | 259/0.254 | 5.46 | 1.58 | 7.89 ± 0.15 |
| 8 | 161/0.254 | 3.72 | 1.58 | 6.88 ± 0.15 |
| 10 | 105/0.254 | 3.01 | 1.58 | 6.17 ± 0.15 |
| 12 | 65/0.254 | 2.37 | 1.58 | 5.53 ± 0.15 |
| 14 | 41/0.254 | 1.88 | 1.58 | 5.05 ± 0.15 |
| 16 | 26/0.254 | 1.50 | 1.58 | 4.66 ± 0.15 |
| 18 | 34/0.18 | 1.21 | 1.58 | 4.38 ± 0.15 |
| 20 | 21/0.18 | 0.95 | 1.58 | 4.12 ± 0.15 |
| 22 | 17/0.16 | 0.76 | 1.58 | 3.93 ± 0.15 |
| 24 | 11/0.16 | 0.62 | 1.58 | 3.78 ± 0.15 |
| 26 | 7/0.16 | 0.49 | 1.58 | 3.66 ± 0.15 |
| 28 | 7/0.127 | 0.39 | 1.58 | 3.56 ± 0.15 |
| 30 | 7/0.10 | 0.31 | 1.58 | 3.47 ± 0.15 |
Why Use Silicone Insulation for 150°C Internal Wiring?
Silicone rubber is selected when the internal wiring zone can operate above the normal range of common PVC hook-up wire. In this construction it supplies the primary electrical insulation and allows a broad conductor-size range within one product family. The value is most relevant in protected equipment compartments where routing, conductor temperature and termination design are controlled. Silicone insulation alone does not make the wire suitable for every environment: sharp-edge abrasion, repeated flexing, oils, outdoor weather, immersion, crushing and tensile load must be assessed separately. The complete assembly remains limited by its lowest-rated terminal, connector, sleeve, adjacent insulation and enclosure component.
Typical Applications for 300V 150°C Silicone Wire
- Protected internal leads in electric heaters, warming equipment and industrial ovens.
- High-temperature hook-up wiring in compatible appliances and enclosed electrical equipment.
- Internal connections between ceramic terminal blocks, controls and heating elements.
- Fixture and luminaire leads where the equipment drawing specifies heat-resistant silicone insulation.
- Motor, transformer and generator lead connections when the electrical and thermal design is compatible.
These are typical engineering contexts, not blanket approvals. Confirm voltage, conductor current, conductor temperature, ambient temperature, enclosure ventilation, vibration, routing, chemical exposure and terminal-system limits for each project.
How Do You Select the Correct UL 3223 Wire?
| RFQ input | Why it matters |
|---|---|
| AWG size and current requirement | Determines conductor cross-section, resistance, voltage drop and heat generation. This page does not assign a universal ampacity. |
| Solid or stranded conductor | Affects routing flexibility, termination method, conductor diameter and finished dimensions. |
| Maximum conductor and ambient temperature | Confirms whether the 150°C construction provides an adequate thermal margin. |
| Termination system | Identifies the required conductor preparation, crimp, screw terminal, sleeve and stripping process. |
| Bending and support | Defines bend radius, support spacing and protection from sharp metal edges. |
| Colour and marking | Supports circuit identification, assembly control and customer drawing requirements. |
| Required tests and documents | Allows the exact production checks and project documentation to be agreed before manufacture. |
Installation Limits and Engineering Notes
- Use the ordered construction within the confirmed 300 V and 150°C limits.
- Use 10 × finished OD as the supplied bend-radius reference unless the approved project data requires a larger radius.
- Protect the silicone insulation from sharp edges, repeated scraping, crushing and unsupported tensile load.
- Do not assume suitability for outdoor exposure, direct burial, immersion, cable-chain motion or continuous flexing.
- Keep the wire clear of moving mechanisms and provide suitable strain relief at terminations.
- Confirm the allowable current from the complete equipment design rather than conductor size alone.
Customisation Available from TEBAOFLEX
TEBAOFLEX can review the documented 4/0–30 AWG dimensional series and project-specific alternatives. Customisation can include conductor size, solid or stranded construction, strand count, insulation colour, printed identification, cut length, coil or reel length and export packaging. Availability, tolerances, minimum production quantity and lead time are confirmed after the requested construction, quantity and delivery destination are known.
Related High-Temperature Wire Options
- UL 3530 silicone wire, 150°C 600V
- UL 3512 silicone wire, 200°C 600V
- UL 3122 silicone fiberglass braided wire, 200°C 300V
- High-temperature and specialty cable range
Frequently Asked Questions
What is UL 3223 wire?
It is a single-core, 300 V silicone-insulated high-temperature hook-up wire with a reference temperature rating of 150°C. The supplied dimensional series covers 4/0–30 AWG.
Is UL 3223 wire suitable for industrial heaters and ovens?
It can be considered for protected internal wiring in compatible heating equipment when the electrical loading, conductor temperature, routing, terminals and surrounding components are within their confirmed limits.
What insulation material is used?
The reference construction uses SR silicone rubber as the primary electrical insulation.
What conductor sizes are available?
The documented stranded-conductor series ranges from 4/0 AWG to 30 AWG. Each size has its own conductor diameter and finished outside diameter.
What is the reference bend radius?
The supplied reference is 10 times the finished outside diameter. Installation temperature, support, strand design and routing conditions may justify a larger bend radius.
Can insulation colour and printing be customised?
Yes, TEBAOFLEX can review colour, identification printing, cut length, reel length and packaging after the conductor construction and order quantity are confirmed.
What information is needed for a quotation?
Provide AWG size, solid or stranded conductor, required voltage and temperature, insulation colour, marking, length, quantity, application, routing conditions, destination country and required production documents.
Send Your UL 3223 Wire Requirements
Send the conductor size, strand design, operating temperature, colour, printing, length, quantity and application conditions. The TEBAOFLEX technical team will review the construction and confirm the applicable product data before quotation.
