UL 3321 XLPE Wire — 150°C / 600V Crosslinked Polyethylene AWM

XLPE Insulation for Higher-Temperature Internal Wiring at a Practical Cost Point

UL Style 3321 is a single-conductor appliance wiring material (AWM) insulated with extruded XLPE (crosslinked polyethylene), rated for 150°C continuous operation at 600V AC / 750V DC. Recognized under UL Subject 758 with a horizontal-flame rating, the style covers conductor sizes from 30 AWG to 4/0 AWG in solid or stranded construction. An optional treated or untreated braid covering is available for applications requiring additional mechanical protection. CableApex supplies UL 3321 wire as a UL Recognized Component — file on record — meeting the full dimensional and performance requirements of UL 758 AWM.

XLPE insulation occupies a practical middle ground between standard PVC hook-up wire rated at 80–105°C and premium fluoropolymer constructions rated above 200°C. For equipment that runs hotter than PVC can tolerate but does not require the cost or chemical-resistance profile of FEP or PFA, UL 3321 delivers the temperature headroom and dielectric strength needed at a significantly lower material cost per metre.

UL 3321 Specification Summary

• Style Number: UL 3321 (AWM, UL 758)
• Temperature Rating: 150°C continuous
• Voltage Rating: 600V AC / 750V DC
• Flame Rating: Horizontal flame
• Conductor Range: 30 AWG – 4/0 AWG, solid or stranded
• Insulation Material: Extruded XLPE (crosslinked polyethylene)
• Min. Insulation Wall (30–9 AWG): 30 mils average / 27 mils at any point (≈ 0.76 mm / 0.69 mm)
• Min. Insulation Wall (8–4 AWG): 45 mils average / 40 mils at any point
• Min. Insulation Wall (3–2 AWG): 60 mils average / 54 mils at any point
• Min. Insulation Wall (1–4/0 AWG): 80 mils average / 72 mils at any point
• Optional Covering: Treated or untreated braid
• Conductor Options: Bare or tinned copper
• UL Status: UL Recognized Component — file on record
• Intended Use: Internal wiring of appliances

Conductor & Dimension Reference

The table below covers the most commonly specified gauges. AWG is the primary sizing reference, with metric cross-section shown for convenience. Final dimensions follow the production datasheet on a per-order basis.

Typical Application Environments

XLPE insulation at 150°C slots into equipment that runs too hot for PVC but does not justify the cost of fluoropolymer wire. UL 3321 is regularly specified in the following environments:

• Motor lead wiring: Internal motor leads that operate at elevated winding temperatures benefit from the 150°C ceiling and 600V dielectric strength, especially in motors rated for Class F (155°C) insulation systems where standard PVC leads would be operating at or above their limit.
• Power control panels and switchgear: Internal bus-to-terminal jumpers and control leads inside enclosed cabinets where ambient temperatures accumulate above 80°C during sustained load conditions.
• Industrial heaters and ovens: Non-heated-zone internal wiring that still experiences convective heat transfer from adjacent high-temperature sections — too hot for PVC, but not in direct contact with the heating element where a 200°C+ silicone or fluoropolymer lead would be needed.
• Transformer and ballast wiring: Internal leads between coil terminals and external junction points where operating temperatures routinely exceed 105°C under rated load.
• EV charging modules and power electronics: Compact power-conversion assemblies where sustained thermal cycling under load demands an insulation system with better long-term heat ageing than standard PVC.

UL 3321 vs Related Internal Wiring Styles

Buyers choosing an internal wire for 600V service compare XLPE, silicone, and fluoropolymer options depending on the temperature profile and cost target. The table below covers the four UL AWM styles most frequently evaluated alongside UL 3321:

UL Recognition

All UL 3321 wire supplied by CableApex is produced under active UL Follow-Up Service as a UL Recognized Component — file on record. Each production reel carries the UL Recognized Component mark in accordance with UL Subject 758 marking requirements. Full recognition documentation is available on request for purchasing, compliance, or import customs purposes.

Order Information

Minimum order quantity is 100 metres per colour per gauge. Quotations are returned within 12 hours of enquiry. Please indicate AWG size, conductor finish (bare or tinned), quantity, colour, and preferred delivery port in the form below.

Related UL Styles for Comparison

• UL 3271 XLPE Wire — 125°C / 600V Motor Leads & Internal Wiring
• UL 3135 Silicone Wire — 200°C / 600V Totally Enclosed
• UL 10362 PFA Wire — 250°C / 600V High-Temperature AWM
• All AWM Wire Styles

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