THHN Wire

THHN wire is a type of electrical wire that's widely used in various applications, including residential, commercial, and industrial settings. Made of a copper conductor, it usually features a thermoplastic insulation made of PVC, as well as a nylon jacket that offers added protection and ease of installation. The letters THHN stand for "Thermoplastic High Heat-resistant Nylon-coated," denoting its primary characteristics and suitability for different environments.
In residential and commercial buildings, THHN wire often serves as building wire for tasks like wiring electrical outlets, switches, and lighting fixtures. It is primarily designed for dry locations but can withstand temperatures up to 90°C. The wire is often found in conduit or raceways and is commonly used for both branch circuits and control circuits. For applications requiring water resistance, you can opt for a dual-rated wire known as THHN/THWN, which is suitable for both wet and dry conditions.
The nylon jacket makes the wire resistant to oil and certain hazardous substances, enhancing its durability. This jacket also makes it easier to pull the wire through conduit, an important consideration for any installation. Stranded copper variations of the wire are often used in applications requiring more flexibility, like machine tools.
Products
More Information about THHN Wire
THHN wire is available in a range of sizes, usually designated by the American Wire Gauge (AWG) system. Both solid and stranded conductors are available, depending on the needs of the application. The wire may come in rolls of varying length, catering to different customer requirements.
THHN wire is an essential material in electrical construction, offering a versatile and reliable option for safely conducting electricity. Its heat-resistant, insulating, and sometimes water-resistant properties make it a go-to choice for a wide range of electrical needs.
FAQs
Are THWN wire and TFFN wire used for the same applications?
While both types of wire can sometimes be found in similar applications such as control circuits or machine tools, THWN is generally better suited for environments that might expose the wire to water or higher temperatures. TFFN, on the other hand, is more often used in lighter, indoor applications requiring flexibility.
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.