Question: what is the difference between insulation types thw and thwn?
Answer: THHN is a code for thermoplastic high heat resistant nylon coated wire which is allowed for use in dry to damp location and rated for a maximum temperature of 90ºC (194ºF). ... The THWN wire we carry is actually coded THWN-2 indicating its rated 90 degrees for both wet or dry locations which is even better.