Explosion proof loop in NEMA 4X junction box


Thread Starter



Can we use a NEMA4x Junction box in a Explosion-proof loop with temperature control loop of electric heaters?

You must consult your local fire codes and determine the electrical area classification for the location where your wiring and circuits are located.
It depends on the area classification of the area where the junction box will be installed in. You should have an area classification drawing delineating these areas. If the area is Division 2 or Zone 2, the NEMA 4x box should work. If it is a Division 1 or Zone 1, then NEMA 4x will not work. Note that that part of the loop can be in a Division 1/Zone 1 area but the 4x box be in a Division 2/Zone 2 area and be ok (seals come into play in this case).

William (Bill) L. Mostia, Jr. PE
ISA Fellow, SIS-TECH Fellow,
FS Eng. (TUV Rheinland)
SIS-TECH Solutions, LP