12 AWG High Temp SIS Switchboard Wire – 125C

“The professional standard for high-density control panelsengineered with high-performance XLPE insulation and tinned copper for maximum reliability in environments up to 125C.”

Why Professionals Choose SIS Switchboard Wire

The 12 AWG SIS wire is a heavy-duty high-temperature conductor designed for precision electrical systems, fully compliant with UL 3173 standards. It is the primary choice for utility-scale switchgear, industrial control panels, and transformer leads. Our Cross-linked polyethylene (XLP) insulation is thermoset, meaning it provides superior resistance to melting or deformation even when exposed to high-thermal stress or accidental contact with soldering equipment.

• 125C Heat Resistance: Rated for continuous use in extreme thermal environments where standard building wire (90C) fails.

• Tinned Copper Conductor: Features a tin coating over the stranded copper to prevent corrosion and ensure effortless soldering and termination in high-humidity panels.

• Chemically Cross-Linked (XLP): The insulation is chemically bonded to ensure it maintains structural integrity under extreme heat.

• UL 3173 / CSA CL1251 Rated: Fully compliant with industrial standards for switchgear, control circuits, and internal appliance wiring.

Technical Specifications

ENGINEERING OVERVIEW: 12 AWG SIS UL 3173 600V

• APPLICATION: Internal wiring of switchboards, control panels, and power distribution equipment.

• VOLTAGE: Rated for 600 Volts.

• CONDUCTORS: 65-strand soft drawn tinned coated copper per ASTM B33 and B174.

• INSULATION: Cross-linked polyethylene (XLP), Type SIS.

• TEMPERATURE: 125C (257F).

• NOMINAL OD: 0.156 inches (3.96 mm).

Common 12 AWG SIS Applications

• Substation Control Wiring: The preferred gauge for high-reliability connections in utility power substations.

• Industrial Power Supplies: Wiring the internal components of large-frame DC power supplies and rectifiers.

• Heavy-Duty Motor Leads: Providing power to industrial motors that operate in high-ambient temperature zones.

• Automated Production Lines: Reliable wiring for the “brains” of manufacturing equipment that faces constant vibration.

• Marine & Harsh Environments: Used in specialized marine panels where tinned copper is required to prevent salt-air corrosion.

Technical Note:All values are nominal and subject to industry tolerances and manufacturer corrections. Specifications are subject to change without notice. It is the buyers responsibility to verify that all materials meet the specific requirements of the project and comply with local electrical codes.