5 minutes to know 3 questions about THHN copper wire and THWN in conduit

This article answers some common questions about THHN copper wire and thwn in conduit from a professional point of view. It is expected to take you about 5 minutes.

Used outside building as a power supply

If you want to lay an electric cable to an outside building as a power supply, selecting the THHN copper wire and thwn in conduit is the best choice. For thwn in conduit, the common sizes contain thwn 10 and 12; On the other hand, 12 and 14 gauge thhn solid wire maybe are the most appropriate sizes. One tip: Not only the thhn stranded cable gauge to be sufficient for the current, but you have to make allowance for worse heat dissipation, so may need to use larger thhn copper cables.

Best wires for residential wiring

Although the Non-metallic sheathed cable commonly used in residential wiring, now more and more countries are encouraging to use THHN copper wire and thwn in conduit, because they allow for changes without opening up any walls. Another factor is price, compared to Non-metallic sheathed cable, the THHN copper wire and thwn in conduit are more affordable, especially on Philippines and whole Latin America.

Why usually is copper used instead of aluminium for THHN stranded wire?

Aluminium is a good conductor of electricity, but aluminium oxide is not. Aluminium is always covered with a film of oxide. If this film is removed, the metal readily reacts with oxygen from the atmosphere, restoring the oxide film. Although copper is more expensive than aluminum, buyers are willing to buy THHN copper wire, considering that THHN stranded wire, as a popular construction wire, relative to more life safety.