THHN Wire

THHN wire is a type of electrical wire that is commonly used as building wire in residential and commercial constructions. The letters THHN stand for Thermoplastic High Heat-resistant Nylon coated, wire which describes the materials that the wire is made of.
The copper conductor of the THHN wire is covered with a thermoplastic PVC insulation that provides protection against moisture and abrasion. This insulation is also rated to withstand high temperatures, typically up to 90°C. In addition, the wire is also coated with a nylon jacket that provides further protection against wear and tear.
THHN wire is available in a range of sizes and colors, and it is often used for wiring control circuits, as well as for lighting and control wiring. It is also suitable for use in conduit, which is a pipe or tube that is used to protect and route electrical wires.
Products
More Information about THHN Wire
THHN wire specifications can vary depending on the manufacturer, but there are some general characteristics that are common to most THHN wires. Here are some common THHN wire specifications:
Conductor Material is typically made of copper, although aluminum is also available.
Conductor Size typically ranges from 14 AWG (American Wire Gauge) to 1000 kcmil (thousand circular mils). The wire size is determined by the cross-sectional area of the conductor, with larger sizes being able to handle more current.
Insulation Material is usually PVC insulation with a nylon jacket. This coating provides additional abrasion and heat resistance.
Temperature Rating for use at temperatures up to 90°C (194°F) in dry or wet locations.
Voltage Rating for use with voltages up to 600 volts.
Color Coding is used to indicate the size and type of the wire. For example, black is commonly used for 2 AWG and larger wires, while red is often used for 10 AWG and smaller wires.
Standards Compliance THHN wire must comply with various industry standards and regulations, including UL (Underwriters Laboratories) standards, NEC (National Electrical Code) requirements, and RoHS (Restriction of Hazardous Substances) directives.
FAQs
Is THHN wire the same as building wire?
THHN wires are a type of building wire, but not all building wire is THHN wire. Building wire is a general term that refers to the different types of wires that are used for electrical wiring in buildings, including residential, commercial, and industrial constructions.
Can THHN wires be used in wiring machine tools?
Yes, THHN wire can be used for wiring machine tools, but it may be necessary to use a larger gauge wire to accommodate the higher current requirements of some machinery.
Are THHN cables the same as THHN wires?
Yes, THHN cables are essentially the same as THHN wires. THHN wire is a single conductor wire that is typically used for applications where the wire is installed in conduit or other enclosed spaces. THHN cable, on the other hand, refers to a bundle of multiple THHN wires that are combined together and encased in an outer nylon jacket or sheath.
What are safety thermoplastic insulated wires?
Safety thermoplastic insulated wires, also known as STW wires, are a type of electrical wire that is commonly used in outdoor and heavy-duty applications where the wire may be exposed to moisture, oil, and other harsh environmental conditions.
What are safety machine tool wires?
Safety machine tool wires, also known as SMT wires, are a type of electrical wire that is specifically designed for use in machine tool applications. SMT wires are constructed with heavy-duty insulation that provides protection against oil, coolant, and other fluids that may be present in machine tool applications.
Does THHN building wire have PVC insulation?
Yes, THHN building wire typically has a PVC insulation with a nylon coating. The PVC insulation provides electrical insulation and protection for the conductor, while the nylon coating provides additional resistance to abrasion, heat, and chemicals.
Industrial Wire Types
THHN Wire
Thermoplastic, High Heat resistant, Nylon jacket insulation (THHN) wire is used in conduit or in cable trays due to its rigidity and tough insulation characteristics. THHN can be stranded (several small strands of wire grouped together), allowing for more flexibility and less chance of breakage, or solid (one wire), which is more durable and rigid. THHN wire is suitable for use in dry locations with temperatures that do not exceed 90 degrees Celsius.
XHHW Wire
Cross-linked polyethylene, High Heat-resistant, Water-resistant (XHHW) wire is very similar to THHN. The difference is that XHHW wire is overall a more durable wire that can withstand higher temperatures and is water resistant. XHHW wire can also be found in both stranded and solid wire options.
MTW Wire
Machine Tool Wire (MTW) wire is much more flexible than THHN wire with insulation that is not as durable, making it a poor choice to run through conduit. The flexibility makes it ideal for winding through tight areas, such as wire ducting in an industrial control cabinet. MTW wire is almost exclusively found in stranded wire, which allows for much of the flexibility and reduces the chances of the wire breaking. MTW wire is intended for use in dry locations that do not exceed 90 degrees Celsius or wet locations that do not to exceed 60 degrees Celsius.