THHN is a Building Wire and cable is used to transmit electrical current to external uses of power in industrial, commercial and residential buildings. The commonly used cable for this purpose is the THHN cable. THHN means Thermoplastic High Heat- resistant Nylon coated. It is ideal for either wet or dry locations. The cable is a designation for particular insulating material, condition of use and temperature ratings. Wires that have the THHN insulation are often used AC electrical distribution systems often at voltage levels ranging from 100 V to 600 V.

Depending on the size of the cable, THHN may come in either stranded or solid conductors. It is manufactured in copper or aluminum covered in poly vinyl chloride insulation and with nylon jacketing. The cable is UL listed and its ratings for dry places stand at 90 degrees where as its ratings for wet locations stand at 75 degrees. The wide majority of THHN cable carries a dual rating on the cable written THHN/ THWN for wet and dry temperature ratings. The THHN building wire could as well be used for the purpose of wiring machine tools, some electrical appliances or on control circuits.

How the THHN cable can be applied
Generally, the THHN insulated wire is used in alternating electrical distribution systems of all kinds in North America. The general areas in which this building cable might be used as stipulated by the National Electrical Code include;

1.In cable tray
2.For feeders
3.For services
4.For wet and dry locations
5.In conduit
6.For branch circuits

THHN wire comes in two kinds of conductors as earlier mentioned. This includes copper or aluminum with regards to the size of the cable. These conductors make the flexibility of the cable to be high as this is a crucial matter especially when it comes to installation. It enhances the installation process and saves time covered. The conductors also make the cable to be durable. It is for this reason that most engineers prefer to use it as a perfect cord in areas where durability is a highly esteemed matter.

The insulating material of the THHN cable is made of poly vinyl chloride (PVC).  This material has high heat and moisture resistance. This factor makes it an ideal cord for use for outdoors in areas where high temperatures are common. A vast majority of cables are not designed to withstand high temperatures. However,the THHN cable displays excellent performance in places with high temperatures. Thanks to the PVC insulation that makes heat not a hindrance to the performance of the cable, it is widely used in fire alarm control systems, heat control systems and push button systems.

THHN cable has a nylon jacketing material. Thanks to this the cable is resistant to moisture, gasoline and oil. During the installation of the cable and after installation, a lot of abrasion takes place in the conduit as a result of pulling. Apart from the provision of mechanical protection, the thermoplastic and nylon sheath provides the cable with resistance from abrasion as it gets pulled from the conduit.  This in long run increases the life of the cable.

The nylon jacket also enables a reduction in the amount of insulation needed and thus enabling the conduit to carry more wires as compared to unjacketed wires of similar current carrying capacity. This factor can be of great benefit when using built- in systems or under floor systems.

Types of THHN cables
Nassau Electrical has a wide selection of THHN cables. Here are the most common types;

1. 6 Gauge THHN THWN – 2 Copper Wire- this is a concentric lay stranded copper conveyor protected with a nylon coat. As the cable is inside the scope of worthy links for use in private wiring, it is often used for general private electrical purposes. The conductor can be used in various industrial and commercial purposes such as branch circuits, service cable trays and electrical feeder cables.

2. 8 Gauge THHN THWN – Copper Wire- this is a medium breadth cable with a permissible having a limit of 40 – 55 amps, contingent upon the link temperature. Just like the previous cable, this one is also used for general private electrical purposes. It is at the littler scope of adequate links for use in private wiring. It can thus be used for home theater wiring and video observing frameworks. The cable is often used in conduit, a tube or trough which channels the wiring and shields the conductors from any sort of interference.

3.10 Gauge THHN THWN – 2 Copper Wire- this is a concentric lay stranded copper conveyor with a protection of nylon coating. It is basically used in conduit and cable trays for services, feeders as well as branch circuits in commercial and industrial applications as stipulated in National Electrical Code 2.

4. 12 Gauge THHN THWN-2 Copper Wire- this one is also a concentric lay stranded copper conduit protected with a nylon coating. The cable is generally used in PCs. It is little size to interface little circuits in PCs and various items. It can as well be used for home theater wiring and video checking frameworks. The nylon coating protects the cable from too much dryness, moisture and sunlight.

5.14 Gauge THHN THWN- 2 Copper Wire- this concentric lay stranded copper conduit is protected with a nylon coat. It is also used for PCs. It is a little size to associate little circuits in PCs and various hardware.  It can therefore be used for wiring home theater and video checking frameworks. The cable is largely used for interior wiring for items such as TVs, radios, speakers and gaming frameworks.

  • Aluminum THHN
  • Copper THHN
  • Tray cable TC TC- ER shielded THHN PVC 18GA
  • Tray cable TC TC- ER shielded THHN PVC 10, 12 and 14GA
  • Tray cable TC TC- ER shielded THHN PVC 16GA
  • Tray cable TC TC- ER shielded THHN PVC 12GA
  • Tray cable TC TC- ER shielded THHN PVC 10GA
  • Tray cable TC TC- ER shielded THHN PVC 14GA
  • Tray cable TC TC- ER shielded THHN PVC with ground 12GA- 500 MCM

THHN cable is generally used in conduit and cable trays for branch circuits, services and feeders in either commercial or industrial applications as stipulated by the National Electrical Code 2. When utilized as THHN type, the conductor is ideal for use in environments that have temperatures not exceeding 90 degrees. When the cable is used as THWN-2 type it is ideal for use only in wet or dry areas with temperatures not going beyond 90 degrees or temperatures not exceeding 75 degrees when used in locations exposing the cable to oil or coolant.

The THHN cable is also ideal for use in wet environments or areas exposed to coolants or oil as long as the temperatures do not go beyond 80 degrees. As a type MTW, it can be used in dry environments that have temperatures standing at or not exceeding 90 degrees (with the ampacity limited to that for 75 degrees conductor temperature as per NFPA 79). The temperatures of the conductor should not go beyond 105 degrees in dry environments when the cable is rated as AMW and utilized as appliance wiring material. The voltage for the areas of applications of the THHN cable is 600 volts. It is also important to note that THHN cable is not permitted for use in direct burial applications.

According to the set specification THHN cable shall be UL listed gasoline and oil resistant. It shall be ideal for use at 600V as stated by the National Electrical Code. Those that range from size 6 AWG to 14 AWG will be rated VW-1. The conductors will be annealed copper with an insulation that is heat and moisture resistant PVC. The cable should be jacketed with abrasion, moisture, gasoline and oil resistant nylon or any other equivalent material.

Because it is always important for safety purposesto work with certified products, THHN cable from Nassau Electrical is certified with international bodies. It meets the standards set by the Underwriters Laboratories (UL) and also those set by the Canadian Standards Association. The cable also meets the American Society for Testing and Materials Miscellaneous (ASTM) requirements. It is also in compliance with the Restriction of Hazardous Substances (RoHS) which limits the use of specific dangerous materials present in electrical and electronic items.

Where to find THHN cable
THHN cable is a common cable with electricians and engineers. You can find in most outlets that deal with electrical products. But remember the market is also flooded with THHN cables of which some do not fully meet the set standards and requirements as set by the National Electrical Code. However, at Nassau Electrical Supply we supply safe THHN cable for the end user as well as the one carrying out the installation. We adhere to all the required standards.

I hope that you found this post very informative. We value you and we’d like to hear from you a bid to serve you better. If need a quote or want some questions answered about the THHN cables, please get in touch with us today and we’ll be glad to get in touch with you. 

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