Some wire jackets are resistant to fire, heat and ultraviolet, while others are better at dealing with moisture. Here are the main types of insulation that you can use:
- THHN is a good choice for indoor solar wiring. This is the most popular type of insulation.
- THW, THWN and TW are okay in wet outdoor applications.
- UF and USE are good for moist or underground applications.
- PV Wire, USE-2 and RHW-2 cables are used for connecting solar panels together. They are UV and moisture resistant.
Solar cable is the preferred choice for PV systems. The difference between a standard one and a PV cable is the insulation. A normal one is PVC-insulated, and the solar cable has an XPLE jacket. This makes PV cable just as sturdy as a solar panel itself. Standard DC cable lasts for 8-10 years, while the lifespan of a PV cable is over 25 years.