What does NEC Class 1, Div. 2, Group B refer to? Especially, what does the “Group B” designate?

3 Comments

1. Chas EE says:

   August 31, 2009 at 3:31 am

   You can view NEC at no charge at: http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=70&cookie%5Ftest=1. After you agree to the terms, you may need to click "Return to the About the Codes page."

   You can see the part about "Group B" here: http://i10.tinypic.com/6tu4zty.jpg
2. vhs_1960 says:

   August 31, 2009 at 3:31 am

   Look in NEC 2005, Article 500.6(A)
3. jesem47 says:

   August 31, 2009 at 3:31 am

   Group B is the type of atmosphere containing:
   butadiene
   ethylene oxide
   hydrogen
   manufactured gases containing more than 30% hydrogen(by volume)
   propylene oxide