Electrical duty
The maximum working voltage and its waveform.
State DC operation and any AC, pulse or transient conditions separately.UL AWM specification guide
UL 3239 Silicone Wire Specification
High-voltage DC
wire specifications.
UL 3239 covers high-voltage DC wire. For a silicone-insulated version, the specification includes conductor size, voltage, temperature and insulation dimensions.
- Voltage basis
- High-voltage DC
- Material to specify
- Silicone version
- Wire specification
- The complete wire version
- Conductor
- Silicone insulation
THE ROLE OF THIS STYLE
Why specify UL 3239 high-voltage silicone wire?
A high-voltage DC connection needs a wire selected for that electrical duty. A familiar single-core shape or a high temperature rating does not tell you its working voltage.
UL 3239 covers multiple voltage and insulation constructions. Ratings and dimensions depend on the version.
START WITH THE REQUIREMENTTHEN IDENTIFY THE VERSION
Material & temperature
The required silicone construction and temperature rating.
A material’s thermal capability and the product’s recognised temperature can be different.Physical construction
The conductor, insulation and finished diameter.
Use the dimensional specification belonging to that same voltage version.Do not combine the highest voltage from one version with the temperature or dimensions of another.
THREE DIFFERENT QUESTIONS
Working voltage is not
test voltage.
Give each electrical condition its own name in the enquiry. A single value labelled “voltage” leaves too much unspecified.
- Working DC voltage
- The voltage the connection must withstand in its intended operating conditions.
Specify the maximum operating requirement, the connection arrangement and the equipment requirement. Select a product rated for that duty.
- Test voltage
- A verification condition used with a defined method, duration and acceptance criterion.
A short-duration test result is not permission to operate continuously at that voltage. Request the test basis as well as the value.
- AC, pulses & transients
- Additional electrical conditions that need their own assessment.
Do not use a DC marking as an automatic AC or pulse rating. Describe the waveform and relevant peaks for engineering review.
ONE NUMBER, MORE THAN ONE CONSTRUCTION
Silicone versions of UL 3239
UL 3239 is not a silicone-only designation. The illustrated wire is one material and construction choice within a broader style.
Conductor
Carries the electrical connection. Conductor size, finish and stranding affect the connection and assembly.
Conductor specification
Cross-section or AWG, material, stranding, current requirement and terminal compatibility.
Silicone insulation
The insulating material in this example. Other UL 3239 products can use different materials.
Insulation specification
The exact compound, recognised temperature, insulation dimensions and voltage version.
Additional layers, if required
A screen, covering or jacket may be part of a different construction. None is shown in the representative section.
Additional layer requirements
Whether extra layers are required, their function, dimensions and the complete product recognition.
Keep the product specification together: material + conductor + voltage + temperature + insulation dimensions + finished diameter. Confirm changes as a new or revised version rather than assuming the other ratings remain unchanged.
Technical references: Alpha Wire 392040 and Rowe UL 3239. These manufacturers' examples do not establish ANYANG product recognition.
SIMILAR SILHOUETTE, DIFFERENT SELECTION
Temperature and voltage rating
The same-looking single conductor can belong to a very different electrical specification.
Selection distinctions, not permission to substitute one style for another. On a small screen, swipe across the table.
| What matters? | UL 3239THIS STYLE | UL 3135 ↗ | UL 3512 ↗ |
|---|---|---|---|
| Electrical reference | High-voltage DC; select a defined rated version | 600 V AC historical reference | 600 V AC historical reference |
| Material identity | Specify silicone; the style also covers other materials | Extruded silicone rubber | Extruded silicone rubber |
| Temperature | Confirm the recognised temperature of that voltage version | 200°C (392°F) historical reference | 200°C (392°F) historical reference |
| Dimensional selection | Conductor and insulation tied to the specified voltage construction | Defined conductor range and wall requirements | Wall requirements depend on the conductor-size band |
Sources: UL 3239 historical style reference, UL 3135 historical style reference, UL 3512 historical style reference. Historical style ranges are not a statement of current supply.
REVIEW THE COMPLETE HIGH-VOLTAGE CONNECTION
The complete high-voltage connection
Have the equipment designer review the complete connection. The complete connection must meet the equipment's requirements for terminations, insulation interfaces and electrical clearances.
DESCRIBE THE INSTALLATION
Operating conditions
- Maximum working voltage, waveform and relevant peaks.
- Conductor current, temperature and routing conditions.
- Termination design, exposed ends and insulation interfaces.
- Humidity, contamination, movement and required verification.
DO NOT INFER FROM THE STYLE NUMBER
- Termination suitability
- The terminal and connection method need their own compatibility review.
- Electrical clearances
- Determine them from the equipment requirements and actual installation, not the cross-section picture.
- Use approval
- An AWM style does not approve the wire for every high-voltage device or installation.
BEFORE YOU SPECIFY
Frequently asked questions
Does every UL 3239 wire have the same voltage rating?
No. Different constructions can have different ratings. Ask for a specification that binds the voltage to the actual material, conductor, dimensions and recognised temperature.
Can I use a DC-rated version for AC operation?
Not automatically. Describe the AC or pulse conditions so the wire version and the complete connection can be assessed.
Does a thicker-looking insulation mean a higher rating?
Not by appearance alone. Material, construction and product recognition matter. The illustration explains the layers; it is not a voltage-selection chart.
Why can a catalogue show two temperature figures?
A supplier may distinguish a material or operating temperature range from a recognised temperature rating. Read the labels and confirm the rating applicable to the specific ordered version.
FROM STYLE TO PRODUCT SPECIFICATION
Discuss a UL 3239 specification
For a quotation, include the required operating voltage, wire size, dimensional limits and quantity.
Electrical requirement
Working DC voltage, AC or pulse conditions, current and required test basis.
Wire & installation
Conductor size, silicone requirement, dimensional limits and connection environment.
Product evidence
Required markings, recognition and drawings for the exact proposed version.
Request a quotation
We offer free samples.