The THW Cable, acronym for water and heat resistant thermoplastic cable, It is a type of electrical cable widely used in residential applications, commercial and industrial. This cable is specifically designed to withstand various environmental conditions, making it a reliable choice for wiring systems exposed to heat, humidity and mechanical stress. The letters of “THW” describe the properties of the cable:
T: thermoplastic insulation, providing flexibility and durability.
H: heat resistant up to 75 °C (167 °F).
W: waterproof, suitable for damp or wet locations.
Los cables THW suelen estar hechos de conductores de cobre o aluminio con una capa de aislamiento termoplástico resistente. This insulation provides abrasion resistance, to chemicals and environmental factors, making THW cable ideal for use in conduit, conduits and open wiring systems.
THW wire application
The versatility of THW cable makes it suitable for a wide range of electrical applications. Next, Some of the most common uses of THW cable are shown:
- Residential wiring
THW cable is often used in homes for interior wiring, especially in circuits requiring durability and moisture resistance. It is ideal for connecting lighting fixtures, plugs and appliances. - Commercial and industrial applications
In commercial and industrial environments, THW cable is used for power distribution and branch circuits. Its heat and water resistance make it a reliable choice for ductwork., ducts and underground wiring systems. - Underground facilities
The water resistant properties of THW cable make it a preferred choice for underground installations. Can be used in direct burial or encapsulated in conduit applications. - Damp and wet locations
Thanks to its water-resistant insulation, THW cable is suitable for areas with high humidity or water exposure, like basements, bathrooms and outdoor environments. - conduit wiring
THW cable is commonly used in conduit for wiring systems where protection against mechanical damage is essential. Its flexibility makes it easy to pass through ductwork during installation. - Service entrance cables
THW cable is often used as part of service entrance cables, that connect the utility company's power lines to a building's electrical panel. - Control and signaling systems
THW cable is also used in control and signaling systems where its durability ensures long-term reliability.
Advantages of THW cable
Heat and water resistance: ideal for harsh environments.
Durability: abrasion resistant, to chemicals and mechanical stress.
Flexibility: easy to install in ducts and pipes.
Versatility: suitable for a wide range of applications, including damp and wet locations.
THW Cable vs THWN Cable
Both THW cable and THWN cable are popular choices in the electrical industry, but they differ in their properties and applications. Next, a detailed comparison is shown:
| Characteristics | Cable THW | Cable THWN |
|---|---|---|
| Isolation | Thermoplastic | Thermoplastic |
| Heat resistance | Up to 75°C (167°F) | Up to 75°C (167°F) for THWN; 90°C (194°F) for THWN-2 |
| Water resistance | Water resistant | Water resistant (suitable for wet locations) |
| Oil resistance | Not oil resistant | Oil resistant (THWN-2 is classified for exhibition acceptance) |
| Applications | General wiring, humid locations | Industrial applications, commercial and exterior |
| Driver material | Generally copper | It covers the aluminum |
| Flexibility | Less flexible compared to THWN cable | More flexible, easy to install in ducts |
Main differences
- Oil resistance
THWN cable has an oil resistant thermoplastic jacket, making it ideal for industrial environments where there is exposure to oils and lubricants. - Temperature rating
Although both cables can withstand up to 75°C, THWN-2 cable can operate at temperatures up to 90°C, which gives it greater heat resistance. - Versatility
THWN cable is more versatile as it can be used in wet conditions and with oil exposure, while THW cable is limited to waterproof environments.
Which one to choose?
- Cable THW: Ideal for residential and commercial installations where water and heat resistance is required in wet or underground locations.
- Cable THWN: Recommended for industrial applications, commercial and exterior where additional oil resistance and greater thermal capacity are required.
THW Cable vs THHN Cable
THW and THHN cables are often compared due to their widespread use in electrical installations. Although they share some similarities, They have clear differences in performance and applications.
| Characteristics | Cable THW | Cable THHN |
|---|---|---|
| Isolation | Thermoplastic | Thermoplastic with nylon cover |
| Heat resistance | Up to 75°C (167°F) | Up to 90°C (194°F) dry; 75°C (167°F) wet |
| Water resistance | Water resistant | Limited to damp locations with additional protection |
| Abrasion resistance | Moderate | Alta (thanks to the nylon cover) |
| Applications | General wiring, humid locations | Dry or slightly damp indoor installations |
| Flexibility | More flexible | Less flexible due to nylon cover |
| Cost | Generally cheaper | More expensive due to longer durability |
Key differences
Nylon coating: THHN cable includes a nylon coating that improves its abrasion resistance, making it suitable for passing through ducts in industrial environments.
Heat resistance: THHN cable has a higher temperature rating (until 90 °C) that the THW cable, making it more suitable for high temperature environments.
Water resistance: although the THW cable is waterproof, THHN cable is not designed for prolonged exposure to water unless specified as THWN rated.
Applications: THHN cable is commonly used for indoor wiring in dry and humid environments, while THW cable is ideal for wet or underground applications.
Cable choice: THW, THWN or THHN ?
When selecting the right cable for your project, Please consider the following factors:
Around:
Use THW cables for wet installations, wet or underground.
Use THWN cables for humid locations with possible oil exposure.
Use THHN cables for dry or slightly damp interior applications.
Temperature requirements:
If the wiring system operates at high temperatures, opt for THWN-2 or THHN cables with higher heat resistance.
Abrasion resistance:
For wiring that passes through conduits, THHN cable with its nylon jacket offers better protection against abrasion.
Cost:
THW cable is usually more affordable, making it a good choice for standard residential and commercial wiring.
Compliance:
Always check local electrical codes to ensure your chosen cable meets safety and regulatory standards.