• Conductor ampacity in foam insulation

    If I run 12 ga THHN in closed cell foam under roof insulation, must I derate that circuit?  I find nothing in NEC.
    last modified by jrlclemson
  • NFPA 52:   &

    Hello,   I would like to get a deeper understanding of the meaning of both of these items regarding CNG tanks.  What is the meaning of a "system to detect the failure of a any one of t...
    last modified by mland