SIS is commonly referred to as Switchboard or Panelboard wire. It is a building wire product made of an insulated copper conductor – usually tin coated – with thermoset, cross-linked polyethylene (XLPE) insulation. The conductors are stranded for high flexibility to make installation in tight spaces easier, and are tinned to facilitate soldering. The XLPE insulation is rated for use at 90°C in either wet or dry locations at an operating voltage of 600 V.

Kris-Tech wire and cable is manufactured in compliance with the applicable requirements of the NEC (National Electrical Code). The insulation properties of SIS are the same as XHHW-2. Although Kris-Tech manufactures SIS in sizes #18 through #4/0 AWG, the smallest UL recognized conductor is #14 AWG. Our standard stock product is gray and is rated VW-1 for flame retardant properties.


SIS conductors are most often used in switchboards and panel boards as specified in the National Electrical Code. Although SIS is not recognized in the NEC Article 310 for use in conduit, Kris-Tech’s is dual-rated as XHHW-2 and is approved to use in recognized raceways. Final approval always rests with your local electrical inspector.


The tough insulation is heat, chemical, oil and moisture resistant, flame retardant and can withstand harsh conditions.


A great flexible control and panelboard wire, and you can substitute it for XHHW-2!


  • UL
  • ASTM
  • ICEA
  • NEMA

All of our building wire is manufactured in compliance with National Electric Code (NEC) Article 310.

Standard Stock Products

  • Sizes #14 through #4/0 AWG
  • Standard Highly Flexible Tinned Stranding
  • Standard insulation is Gray XLPE, VW-1 Rated

Custom Options

  • Up to 12 color options
  • Coils in Knock-Out Cartons
  • #18 and #16 AWG constructions
  • Optional Stand Counts: Have a 7-Strand spec? Give us a call.
  • Striping, Twisting and Paralleling
  • Custom lengths and packaging