rusty6
Member
- Location
- Los Angeles
Our company designs sensors used to measure different gaseous components. Typically, we design enclosed sample panels to condition the samples in order to measure them. Our analyzers are explosion-proof but we typically contain our sample conditioning panels inside a NEMA4X enclosure. My question is this: if the gases flowing through the sample conditioning system are combustible, is the inside of our enclosure Division 1 or Division 2? I ask because I want to make sure we are sealing our conduit correctly and in the correct locations.
My confusion comes from the NEC definitions of Div 1 vs Div 2.
500.5(B)(1)(2): In which ignitible concentrations of such flammable gases,flammable liquid–produced vapors, or combustible liquids above
their flash points may exist frequently because of repair or
maintenance operations or because of leakage,
vs.
500.5(B)(2)(1): In which volatile flammable gases, flammable liquid–producedvapors, or combustible liquid–produced vapors are handled,
processed, or used, but in which the liquids, vapors, or gases
will normally be confined within closed containers or closed
systems from which they can escape only in case of accidental
rupture or breakdown of such containers or systems or in case
of abnormal operation of equipment,
What is the difference here between leakage and abnormal operation of equipment? Aren't valves and fittings only supposed to leak under "abnormal operation of equipment?"
Apologies for the long post, any input would be extremely helpful.
My confusion comes from the NEC definitions of Div 1 vs Div 2.
500.5(B)(1)(2): In which ignitible concentrations of such flammable gases,flammable liquid–produced vapors, or combustible liquids above
their flash points may exist frequently because of repair or
maintenance operations or because of leakage,
vs.
500.5(B)(2)(1): In which volatile flammable gases, flammable liquid–producedvapors, or combustible liquid–produced vapors are handled,
processed, or used, but in which the liquids, vapors, or gases
will normally be confined within closed containers or closed
systems from which they can escape only in case of accidental
rupture or breakdown of such containers or systems or in case
of abnormal operation of equipment,
What is the difference here between leakage and abnormal operation of equipment? Aren't valves and fittings only supposed to leak under "abnormal operation of equipment?"
Apologies for the long post, any input would be extremely helpful.