Classes of wiring


Thread Starter

Gee, Jeffrey

Can someone give me a good description of the differences between Class I, Class II, and Class III power sources?

How can I easily tell the difference between them?
When is each used?

Ref NEC Art 725

William L. Mostia, Jr

I don't know if there is a simple description of these classes. The NFPA NEC Handbook may be of some assistance. There is an article, "Classification of circuits under Article 725," in September 1998 of CEE News by Noel Williams that was written due to a question by me to their code panel. It is the only article that I have seen on this subject. Bill Mostia ========================================================= William(Bill) L. Mostia, Jr. PE Principal Engineer WLM Engineering Co Independent I&E Consultant P.O. Box 1129 Kemah, TX 77565 USA 281-334-3169 E-Mail: [email protected] These opinions are my own and are offered on the basis of Caveat Emptor.