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Product

High-temperature wireUL AWM Style 32393 kV to 50 kV DCUL VW-1 Silicone

UL AWM 3239 High-Voltage Silicone Lead WireUL 758 Style 3239 3 kV to 50 kV DC corona-resistant silicone high-voltage lead wire

UL AWM Style 3239 flexible high-voltage DC silicone lead wire with stranded tinned copper conductors (28–10 AWG) and void-free extruded silicone rubber insulation in voltage classes from 3 kV DC to 50 kV DC (-60 °C to +150/+200 °C, UL VW-1).

Flame-retardant

Approved

Ozone, UV & moisture

Configuration

Order designation: UL 3239 18 AWG 20 kV DC
Outer Ø ≈: 5.00 mm
Wall thickness: 1.90 mm
Total weight ≈: 32.0 kg/km
Min. bend R (fixed): 30 mm

All sizes (10)

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Engineering reply in 2 business hoursCut-to-length export drumsEN 10204 3.1 certificate per drum

Rated voltage: 3 to 50 kV DC
Temperature: -60…+150 °C
Conductor: Tinned Cu
Insulation: Corona-free VMQ
Flame rating: UL VW-1 / FT1
Test voltage: 2 × kV + 1 kV

Typical values for this cable type, based on UL 758 AWM Style 3239 — confirmed in the datasheet and quotation for your order.

Application fit

Is UL AWM 3239 right for your machine?

Select UL AWM 3239 by exact DC working voltage (3, 6, 10, 15, 20, 25, 30, 40, or 50 kV DC) for high-voltage power supplies, CO2 lasers, medical X-ray generators, and electrostatic equipment.

Switchgear & control cabinet wiring

Suitable

Supple silicone insulation bends tightly inside compact HV DC power supplies, voltage multipliers, and laser exciters.

Furnace, kiln & high-temp zone

Suitable

Operates reliably from -60 °C to +150 °C (+200 °C compound) in plasma treaters, UV curing lamps, and burner transformers.

Fixed installation

Suitable

UL VW-1 flame-retardant wall allows direct internal chassis routing without secondary flame-retardant sleeving.

Motorised monospiral reel

Not suitable

Single-core electronic HV hook-up wire is intended for internal equipment wiring, not mechanical drum reeling.

Use NSHTÖU for drum reeling

Typical machinesHV DC Power Supplies & LasersMedical X-Ray & CT ScannersElectrostatic Precipitators & IonisersSemiconductor Ion ImplantersAnalytical & Mass Spectrometers

Construction

Layer by layer

UL 758 Style 3239 single-core HV lead wire: flexible stranded tinned copper conductor and pressure-extruded void-free HV silicone rubber wall.

Schematic, not to scale — generated from the layer data

#	Layer	Material & reference
1	Flexible stranded tinned copper	Tinned annealed electrolytic copper (ASTM B33, 28 AWG to 10 AWG)Smooth concentric bundle contour minimizes local electric field stress
2	Void-free extrusion boundary	High-pressure extruded conductor-to-silicone interfacePrevents air pockets that cause partial discharge (corona) under HV DC
3	Graded HV silicone dielectric	High-purity methyl-vinyl silicone rubber (VMQ, 0.76 mm to 3.81 mm wall)Graded wall thickness matched to 3, 6, 10, 15, 20, 25, 30, 40, or 50 kV DC
4	UL VW-1 anti-tracking surface	Smooth low-leakage flame-retardant silicone surface (red, white, or black)Passes UL 1581 VW-1 vertical flame test and resists surface arcing

UL 3239 3–15 kV DC

Compact HV lead wire (0.76–1.52 mm wall) for laser tubes, photomultipliers, and HV modules

UL 3239 20–50 kV DC

Heavy-wall HV lead wire (1.90–3.81 mm wall) for X-ray anodes, e-beam guns, and precipitators

Technical data

Ratings & operating limits

Typical values: Typical values for this cable type, based on UL 758 AWM Style 3239. Values for your order are confirmed in the datasheet and quotation.

Electrical

UL rated DC voltage classes: 3, 6, 10, 15, 20, 25, 30, 40, 50 kV DC
UL dielectric withstand test: 7.5 kV to 75 kV DC (per voltage grade)
Volume resistivity: ≥ 1 × 10¹⁵ Ω·cm at +20 °C
Dielectric constant (1 kHz): 2.9 to 3.1 (low capacitive loading)

Thermal

UL rated temperature: -60 °C to +150 °C (UL 3239 standard)
Compound thermal capability: Up to +200 °C continuous in air
Cold flexibility limit: -60 °C without cracking

Mechanical

Conductor size range: 28 AWG to 10 AWG (0.08 to 5.26 mm²)
Insulation wall range: 30 mil (0.76 mm) to 150 mil (3.81 mm)
Min. bending radius: 5 × overall wire diameter (fixed)

Resistance

Flame retardance: UL 1581 VW-1 vertical wire flame pass
Corona & ozone resistance: Excellent HV corona & ozone stability
Halogen-free compound: IEC 60754-1/2 halogen-free silicone

Reference standards

Primary standard: UL 758 AWM Style 3239
Conductor specification: ASTM B33 tinned stranded copper
RoHS & REACH: RoHS 3 & REACH compliant

Identification

Insulation colours: Red, white, black (custom colours on request)
Surface legend: TEBAOFLEX E-FILE AWM 3239 [AWG] 150C [kV]DC VW-1
Customs tariff (HS): 8544.49

Sizes

10 standard configurations (UL AWM 3239)

Engineering dimensions, conductor stranding, mass and electrical ratings for UL AWM 3239 per UL 758 AWM Style 3239.

Dimensions & weights
Order designation	Cross-section / size	Conductor build	Wall ≈ mm	Outer Ø ≈ mm	Metal kg/km	Weight ≈ kg/km	Min. bend R fixed mm
Standard UL AWM 3239 configurations
UL 3239 24 AWG 3 kV DC	24 AWG (0.20 mm²)	11×0.16 mm Sn-Cu	0.76	2.20	2.0	6.5	13
UL 3239 22 AWG 6 kV DC	22 AWG (0.35 mm²)	17×0.16 mm Sn-Cu	0.90	2.60	3.4	9.2	16
UL 3239 22 AWG 10 kV DC	22 AWG (0.35 mm²)	17×0.16 mm Sn-Cu	1.15	3.10	3.4	12.5	19
UL 3239 18 AWG 10 kV DC	18 AWG (0.82 mm²)	41×0.16 mm Sn-Cu	1.15	3.50	8.2	18.0	21
UL 3239 20 AWG 15 kV DC	20 AWG (0.52 mm²)	26×0.16 mm Sn-Cu	1.52	4.00	5.2	21.0	24
UL 3239 18 AWG 20 kV DC	18 AWG (0.82 mm²)	41×0.16 mm Sn-Cu	1.90	5.00	8.2	32.0	30
UL 3239 18 AWG 25 kV DC	18 AWG (0.82 mm²)	41×0.16 mm Sn-Cu	2.15	5.50	8.2	38.0	33
UL 3239 16 AWG 30 kV DC	16 AWG (1.31 mm²)	65×0.16 mm Sn-Cu	2.46	6.40	13.0	52.0	38
UL 3239 16 AWG 40 kV DC	16 AWG (1.31 mm²)	65×0.16 mm Sn-Cu	3.10	7.70	13.0	74.0	46
UL 3239 14 AWG 50 kV DC	14 AWG (2.08 mm²)	105×0.16 mm Sn-Cu	3.81	9.50	20.5	112.0	57

Typical values for this cable type; dimensions and weights for your order are confirmed in the quotation.
Outer diameters and weights are nominal engineering values for UL AWM 3239 subject to standard manufacturing tolerances per UL 758 AWM Style 3239.

Electrical & rating data
Configuration	Max. DC R @ 20 °C Ω/km	Primary rating (A or kV)	Derated / AC rating	Dielectric test V AC rms
UL 3239 24 AWG 3 kV DC (24 AWG (0.20 mm²))	86.00	3.0	1.0	7,500
UL 3239 22 AWG 6 kV DC (22 AWG (0.35 mm²))	53.00	6.0	3.0	15,000
UL 3239 22 AWG 10 kV DC (22 AWG (0.35 mm²))	53.00	10.0	4.0	22,000
UL 3239 18 AWG 10 kV DC (18 AWG (0.82 mm²))	21.40	10.0	4.0	22,000
UL 3239 20 AWG 15 kV DC (20 AWG (0.52 mm²))	33.80	15.0	7.0	32,000
UL 3239 18 AWG 20 kV DC (18 AWG (0.82 mm²))	21.40	20.0	9.0	42,000
UL 3239 18 AWG 25 kV DC (18 AWG (0.82 mm²))	21.40	25.0	11.0	50,000
UL 3239 16 AWG 30 kV DC (16 AWG (1.31 mm²))	13.50	30.0	14.0	60,000
UL 3239 16 AWG 40 kV DC (16 AWG (1.31 mm²))	13.50	40.0	18.0	75,000
UL 3239 14 AWG 50 kV DC (14 AWG (2.08 mm²))	8.50	50.0	22.0	90,000

Electrical resistance at +20 °C and dielectric withstand voltages verified per UL 758 AWM Style 3239.

Quality & approvals

Testing & inspection

Routine tests on every production length, sample and type tests per batch — documented on an EN 10204 3.1 inspection certificate.

ConductorClass 5 stranding
Spark test100 % in-line
Lay-upCores, earth, fillers
SheathingInner, braid / screen, outer
Electrical testsAC voltage, resistance
DimensionsOD, wall thickness
Inspection documents & dispatchDrum & dispatch

Testing & inspection	Test value / reference	Frequency
Routine tests
Dielectric spark / high-voltage withstand test	100 % in-line spark and AC/DC dielectric withstand per UL 758 AWM Style 3239	Every manufactured length
Conductor DC resistance & continuity check	Within maximum 20 °C resistance limit specified for UL AWM 3239	Every spool or drum length
Sample tests
Thermal ageing & dimensional verification	Wall thickness, concentricity and post-ageing elongation per UL 758 AWM Style 3239	Per production batch
Flame, outgassing or high-temperature endurance	Qualified to UL 758 AWM Style 3239 thermal and environmental performance criteria	Type qualification

Inspection certificate

Issued with every drum, listing the routine test results for that length.

Product approvals

UL 758 AWM Style 3239CE (2014/35/EU) & RoHS 3 (2015/863/EU) CompliantREACH SVHC & Halogen/Asbestos Compliance Verified

Company certificates

ISO 9001ISO 14001ISO 45001VDE marks approvalUL / cULCE · LVD / EMC

Marking & supply

Ordering & delivery

Sheath marking

TEBAOFLEX E-FILE AWM STYLE 3239 18 AWG 150C 20KVDC VW-1

Delivery form: Precision spools, coils or export wooden drums
Standard lengths: 50 m · 100 m · 500 m · 1000 m (or cut harnesses)
MOQ: 100 m (stock sizes) · 300–500 m (custom build)
Lead time: 2–4 weeks ex-works
Incoterms: EXW, FOB, CIF, DAP

Technical documents

Downloads

PDFUL AWM 3239 High-Voltage Silicone Lead Wire – technical datasheet10 sizes · construction, technical data, approvals XLSXUL AWM 3239 spec data (Excel)All 10 sizes with dimensions and data, for your BOM or quotation

Revision: 2026-10-20
Updated: 2026-10-20

FAQ

Questions engineers ask first

Not covered here? Send your drawing — an engineer replies within 2 business hours.

How do I convert UL 3239's DC voltage rating to an equivalent 50/60 Hz AC rms working voltage?

UL 3239 is rated in DC kilovolts (3 kV to 50 kV DC). For continuous sinusoidal 50/60 Hz AC operation where polarity reversal stresses the dielectric continuously, divide the DC rating by approximately 2.5 to 3.0 (for example, 30 kV DC wire is typically operated up to 10 kV AC rms).

Why is pressure-extruded void-free silicone critical in 20 kV to 50 kV DC lead wires?

At electric field gradients above 5 kV/mm, any microscopic air pocket between the stranded copper conductor and the insulation ionises into ozone-producing partial discharge (corona), which erodes standard rubber from the inside out. Void-free extrusion eliminates internal corona.

When should I choose UL 3257 instead of UL 3239?

Choose UL 3239 for high-voltage DC electronics, lasers, and power supplies from 3 kV to 50 kV DC up to +150/+200 °C. If the wire sits inside a +250 °C thermal zone (such as a pyrolytic oven igniter), specify UL 3257 with its nickel-plated copper conductor.

Does UL 3239 pass the UL VW-1 vertical flame test without an outer glass braid?

Yes. The flame-retardant silicone compound used in our UL 3239 series passes the UL 1581 VW-1 vertical wire flame test directly, providing clean, dust-free stripping for cleanroom and medical high-voltage assemblies.

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03Message for our engineers

UL AWM 3239 High-Voltage Silicone Lead Wire

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Reel & motion:
- Reel type: 
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Datasheet Request a quote

UL AWM 3239 High-Voltage Silicone Lead WireUL 758 Style 3239 3 kV to 50 kV DC corona-resistant silicone high-voltage lead wire

Switchgear & control cabinet wiring

Furnace, kiln & high-temp zone

Fixed installation

Motorised monospiral reel

UL 3239 3–15 kV DC

UL 3239 20–50 kV DC

Electrical

Thermal

Mechanical

Resistance

Reference standards

Identification

Inspection certificate

Product approvals

Company certificates

01Selected sizes

02Reel & motion

03Message for our engineers

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