UL Building Wire (TFFN/THHN, XHHW)

UL/CSA Building wire and cable is used in the construction of almost every commercial, industrial, and residential property in the world. Most commonly known as branch circuit wiring in homes and businesses, these products carry electrical current to all power applications in a building or dwelling.

UL/CSA Building wire and cable must be sized and installed correctly to keep electricity running. Categories include all types identified in the National Electrical Code® (NEC), Underwriters Laboratories (UL), CSA Standards, Mexican Electrical Code, and the Association Nacional de Normalización y Certificación del Sector Eléctrico (ANCE) Standards, including:

  • Armoured cables
  • Flexible metal conduit and liquidtight flexible metal conduit
  • Metal-clad cables
  • Nonmetallic sheathed cables
  • Service entrance cables
  • Thermoplastic and thermoset insulated wires and cables

We supply a range of Building Wire cables types such as THHN, THWN, THWN-2, TFFN, TFN, TWEN, XHHW, RHH, RHW, USE-2 and NM-B cable.

Southwire Building Wire

Southwire THHN building wire

THHN – Thermoplastic High Heat-resistant Nylon-coated
600 Volts. Copper Conductor. Thermoplastic Insulation/Nylon Sheath, Heat, Moisture, Gasoline and Oil Resistant II. All Sizes Rated Both THHN and either THWN (sizes 14, 12, and 10 AWG) or THWN-2 (sizes 8 AWG and larger). Also Rated MTW and AWM (See Below). SIMpull® Technology for Easier Pulling

Southwire TFFN building wire

TFFN – Thermoplastic Flexible Fixture Nylon
600 Volt. Copper Conductor. Thermoplastic Insulation/Nylon Sheath. Heat, Moisture, Oil, and Gasoline Resistant II. Also Rated MTW and 105 °C AWM. Also Available, TFN and TEWN


XHHW-2 LSZH Solid or Stranded Low Smoke Zero Halogen
CU 600V or 1000V LSZH XHHW-2 SOLONONplus® Living Building Challenge (LBC) Red List Free. SOLONONplus® 600Volt or 1000V Single Conductor Copper Cross Linked Polyolefin Low Smoke Zero Halogen (XLPO LSZH) Insulation Type XHHW-2

XHHW-2 LSZH Stranded Low Smoke Zero Halogen
CU 600V LSZH XHHW-2 SOLONONplus®SOLONONplus® 600Volt Single Conductor Copper Cross Linked Polyolefin Low Smoke Zero Halogen (XLPO LSZH) Insulation Type

Southwire XHHW building wire

XHHW – XLPE (cross-linked polyethylene) High Heat-resistant Water-resistant
600 Volts & 1,000 Volts. Copper Conductor. Cross-Linked Polyethylene (XLPE) Insulation. High-Heat and Moisture Resistant. SIM Technology® for easier pulling. Sizes 14 through 10 AWG also rated SIS

Southwire RHH/RHW & USE building wire

RHH/RHW-2, USE-2 – Rubber High Heat/Wet, Underground Service Entrance Cable
Underground Service Entrance Cable. 600 Volt. Copper Conductors. Cross-Linked Polyethylene (XLP) Insulation. High-Heat, Moisture, and Sunlight Resistant. Sizes 6 Through 4/0 AWG Also Rated SIS

Southwire NM-B Romex building wire

NM-B – Non Metallic
Nonmetallic-Sheathed Cable. 600 Volt. Copper Conductors. Color-Coded Jacket. Four Conductor Available With Two Neutrals. SIMpull® Jacket Designed for Easier Pulling