18 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 18 AWG SIS wire is a specialized 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.

SIS Technical Specifications

ENGINEERING OVERVIEW: 18 AWG SIS UL 3173 600V

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

• VOLTAGE: Rated for 600 Volts.

• CONDUCTORS: 16-strand soft drawn tinned coated copper per ASTM B33 and B174.

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

• TEMPERATURE: 125C (257F).

• NOMINAL OD: 0.111 inches (2.82 mm).

Common 18 AWG SIS Applications

• Electrical Switchgear: The primary choice for internal wiring of utility-scale substations and distribution panels.

• Control & Relay Panels: Ideal for high-density wiring of industrial relays, contactors, and terminal blocks.

• Motor & Transformer Leads: Used for internal coil leads and motor connections that operate at elevated temperatures.

• Commercial Lighting: A popular choice for high-intensity discharge (HID) or specialized industrial lighting fixtures.

• Industrial Computers: Providing stable power and signal within heavy-duty manufacturing computer cabinets.

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.