Module 1 - Lesson 3 Part 3: Electrical Conductors and Applications

TH Thermoplastic Heat-Resistant Wire

Low heat-resistant thermoplastic insulation (up to 75°C)

TH Thermoplastic Heat-Resistant Wire

Indoor dry locations; conduit wiring; less common in modern installations

TW Thermoplastic Wet Wire

Moisture-resistant thermoplastic insulation

TW Thermoplastic Wet Wire

Indoor wet locations; conduit wiring; less common in modern installations

THW Thermoplastic Heat- and Water-Resistant Wire

Heat-resistant (up to 75°C) and moisture-resistant thermoplastic insulation

THW Thermoplastic Heat- and Water-Resistant Wire

Indoor wet and dry locations; conduit wiring

NM/NM-B Nonmetallic Sheathed Cable (Romex)

Moisture-resistant, heat-rated (90°C) nonmetallic sheathed cable

NM/NM-B Nonmetallic Sheathed Cable (Romex)

Indoor dry locations only (e.g., residential wiring inside walls); not allowed in wet locations; conduit not required

BX/AC Armored Cable

Flexible metal-sheathed cable providing mechanical protection

BX/AC Armored Cable

Indoor dry locations; exposed wiring where armor protects the cable; not suitable for wet locations

THHX Thermoplastic High Heat-Resistant Wire

High heat-resistant (90°C+) thermoplastic insulation

THHX Thermoplastic High Heat-Resistant Wire

Indoor dry, high-temperature applications; industrial facilities

THHN Thermoplastic High Heat-Resistant Nylon-Coated Wire

Nylon-coated, high-heat-resistant (up to 90°C) thermoplastic insulation

THHN Thermoplastic High Heat-Resistant Nylon-Coated Wire

General indoor & outdoor wiring in conduit; feeders and branch circuits; dry to damp locations

THWN Thermoplastic Heat- and Water-Resistant Nylon-Coated Wire

Nylon-coated, heat- (up to 90°C) and moistureresistant thermoplastic insulation

THWN Thermoplastic Heat- and Water-Resistant Nylon-Coated Wire

Indoor/outdoor wet and dry locations; feeders and branch circuits; commonly dual-rated as THHN/THWN-2

XHHW Cross-Linked Polyethylene (XLPE) Wire

XLPE-insulated, high-heat (up to 90°C) & moisture-resistant insulation; excellent thermal and electrical properties

XHHW Cross-Linked Polyethylene (XLPE) Wire

High-voltage applications, underground systems, service feeders, power distribution, highhazardous areas

Busbars

Solid metallic conductor bars in a busway enclosure for high-current distribution

Busbars

Large power distribution systems, substations, industrial electrical systems

Cable Bus

Parallel insulated cables enclosed in a metal housing, designed for high-current distribution with routing flexibility

Cable Bus

Large industrial plants, substations; ideal where space efficiency and long-distance distribution are required