UL1592 FEP Wire

UL 1592 FEP Wire — 200°C, 300 Vac Fine-Gauge Internal Wiring with Defined Tinned Copper Limits

UL 1592 is a single-conductor appliance wiring material with extruded FEP insulation, rated 200°C maximum at 300 Vac with a horizontal flame rating, evaluated under UL Subject 758. It covers 32 AWG through 16 AWG in solid or stranded construction, with a single insulation specification of 16 mils minimum average thickness and 13 mils minimum at any point across the full range. Its permitted use is internal wiring, stated without restriction to appliances — a broader scope than most styles in this family. CableApex supplies UL 1592 as a UL Recognized Component — file on record.

200°C in a Fine-Gauge, 300 V Class Style

Most fluoropolymer styles reaching 200°C also carry a 600 Vac rating and a conductor range extending well into heavy gauges. UL 1592 does neither: it stays at 300 Vac and stops at 16 AWG. That combination is deliberate and useful. A fine sensor or signal lead routed through a genuinely hot zone needs the temperature class but rarely needs the voltage class, and a 600 V wall on a 30 AWG conductor adds diameter that a dense harness cannot always accommodate. UL 1592 supplies the 200°C rating at a 16 mils wall, giving a finished diameter appropriate to the conductor rather than to a voltage requirement the circuit does not have.

The Tinned Copper Constraint

Where UL 1591 recognises a range of conductor platings across its whole conductor span, UL 1592 places a specific limit on tinned copper: it is permitted only in sizes 26 AWG through 16 AWG, and the tinned copper strands must be a minimum of 15 mils in diameter. Both parts of that constraint matter when specifying.

The size limit means tinned copper is not available in the finest sizes of the style — a 30 AWG or 28 AWG conductor under UL 1592 must use another conductor treatment. The strand diameter minimum means that within the permitted sizes, a highly stranded construction built from very fine strands may not qualify even if the overall AWG falls in range, because each individual strand must meet the 15 mils floor. This effectively rules out fine-strand high-flex constructions in tinned copper under this style. Where a design requires both tinned copper and a fine or highly stranded conductor, UL 1591 at 150°C is generally the more workable style. Confirm conductor construction and plating together at time of order so both constraints can be verified against the intended build.

Comparing UL 1592 with UL 1591 and the 600 V FEP Styles

Against UL 1591, UL 1592 offers 50°C more headroom over the identical conductor range, wall thickness and voltage rating, at the cost of the tinned copper restrictions described above and a permitted use stated as internal wiring rather than internal wiring of appliances. Against UL 1330, which also reaches 200°C, UL 1592 trades the 600 Vac rating and the 4/0 AWG conductor reach for a thinner 16 mils wall and a fine-gauge focus. Where a 200°C lead is fine-gauge and the circuit is 300 V class, UL 1592 is usually the closest fit of the three.

Permitted Use and Ordering

The permitted use for UL 1592 is internal wiring. For applications outside internal wiring, confirm application suitability before specifying. Marking follows UL Subject 758 marking requirements, and RoHS/REACH documentation is available on request. CableApex supplies UL 1592 from 100 m per color, in solid or stranded construction with conductor material and plating confirmed at order against the style’s constraints, and answers B2B inquiries within 12 hours with pricing, lead time and packing details. Browse the UL 1592 products below by AWG size, or submit your specification through any product page inquiry form.