What Is TFFN Fixture Wire?

Type TFFN wire falls under the National Electrical Code as a fixture wire. This wire has a voltage rating of 600 volts and a maximum usable temperature of 90 degrees Celsius. You can use TFFN as per the NEC for the wiring of lighting fixtures and other types of equipment where the wires are enclosed and protected. You're also permitted to use fixture wires to connect to branch circuits, although fixture wires may not be part of a branch circuit.

Although relatively flexible, the NEC requires that wires aren't subject to twisting or bending during use. There are only two approved wire sizes, 18 and 16 American Wire Gauge, with a specified maximum ampacity of 6 amps for 18 AWG and 8 amps for 16 AWG.

The Letters TFFN indicate that the wire has thermoplastic insulation, in this case, polyvinyl chloride, is a flexible fixture wire, and has a nylon jacket.

4 items

  • TFFN 18 16
    $0.00 / 1000 FT
    • Ampacity (90C): 6
    • Approx LBS/MFT: 7.00
    • AWG Size: 18
    View Details
  • TFN 18 1
    $0.00 / 1000 FT
    • Ampacity (90C): 6
    • Approx LBS/MFT: 7.00
    • AWG Size: 18
    View Details
  • TFFN 16 26
    $0.00 / 1000 FT
    • Ampacity (90C): 8
    • Approx LBS/MFT: 11.00
    • AWG Size: 16
    View Details
  • TFN 16 1
    $0.00 / 1000 FT
    • Ampacity (90C): 8
    • Approx LBS/MFT: 10.00
    • AWG Size: 16
    View Details

The Difference Between TFFN and TFN Wires

TFN wires are another type of fixture wire approved by the NEC. These wires have a solid copper conductor. They meet the same technical requirements as TFFN wires, have the same ampacity, and are available in 18 and 16 AWG sizes.  

TFFN and TFN Fixture Wire Construction

Conductors

Although the specifications allow the use of aluminum, AWC TFN wires use annealed copper conductors. While slightly heavier than aluminum, copper isn't subject to oxidation and doesn't require special joining techniques. TFN wires have a solid conductor, while TFFN wires use stranded conductors.

Insulation

Both types of wire have thermoplastic extruded PVC insulation. PVC has good oil, acid, and alkali resistance, and while it burns, has flame-retardant properties. The nominal insulation thickness for all types is 0.015 inches.

Jacket

TFFN and TFN wires have a thin outer jacket made from nylon. Nylon is tough, abrasion-resistant, and protects fixture cables when pulled through conduits.  

Alternative Applications of TFFN and TFN Wires

Many TFFN and TFN cables supplied by AWC are dual rated. You will find this information stamped or printed on the cable jacket. When you use a dual-rated cable for another application, the cable rating may be different from the equivalent NEC rating.

Machine Tool Wire

Our TFFN wires carry a dual MTW rating under UL1063. When used for machine tool wiring, their maximum voltage is 300 volts and the maximum usable temperature is 60 C.

Appliance Wiring Material Ratings

AWC wires with a TFFN and TFN rating also meet three UL appliance wiring material (AWM) styles.

  • UL1316: For the internal appliance wiring with a maximum voltage rating of 600 volts and a maximum temperature, with copper conductors, of 105 C dry and 60 C in the presence of oil or gasoline.
  • UL1408: For the internal wiring of appliances with a maximum voltage rating of 600 volts and a maximum dry temperature of 90 C and 60 C in the presence of oil or moisture. The tag may indicate a peak voltage of 2,500 volts for electronic use.
  • UL1452: For the internal wiring of appliances with a voltage rating of 1,000 volts and a maximum dry temperature of 90 C and 60 C in presence of oil or gasoline. The tag may indicate a peak voltage of 3,500 volts for electronic use and whether you can immerse the cable in oil or gasoline.

TFFN and TFN Wire Specifications

  • Conductor: Pure annealed copper wire, stranded for TFFN and solid for TFN
  • Insulation: Extruded thermoplastic material, PVC
  • Jacket: Extruded nylon jacket
  • Maximum temperature as NEC fixture wire: 90°C
  • Maximum temperature as MTW wire: 60°C
  • Maximum temperature as UL AWM: Between 90°C and 105°C
  • Maximum voltage NEC: 600 volts
  • Maximum voltage as ATW wire: 300 volts
  • Maximum voltage as UL AWM: between 600 and 1,000 volts.
  • AWG sizes: 18 and 16 AWG

TFFN and TFN Wire Certifications

  • NEC: TFFN And TFN
  • UL66 for TFFN
  • UL1063 for MTW
  • UL-758 for AWM Styles 1316, 1408, 1452
  • CSA-C22.2 No. 127 TEWN 105°C
  • UL: 90°C, 600V / 1452: 1000 volts
  • Restriction of Hazardous Substances (RoHS) on Request
Contact us for help and technical advice on selecting TFFN or TFN wire.