Lights in Class 1 Div 1 area

[kjroller]

Do lights in a Class 1 Div 1 area need a seal off or are they considered not arcing and sparking? Let me know your thoughts thank you!

 

[Dsg319]

Do lights in a Class 1 Div 1 area need a seal off or are they considered not arcing and sparking? Let me know your thoughts thank you!

Probably depends on the manufacturer . See the language on the fixture itself should say.

 

[Besoeker3]

Do lights in a Class 1 Div 1 area need a seal off or are they considered not arcing and sparking? Let me know your thoughts thank you!

I don't know - are they incandescent or light emitting ?

 

[DBill64]

NEC 2023:

501.15(A) Conduit Seals, Class I, Division 1.
In Class I, Division 1 locations, conduit seals shall be located in accordance with 501.15(A)(1) through (A)(4).

(1) Entering Enclosures.
Each conduit entry into an explosionproof enclosure shall have a conduit seal where either of the following conditions apply:

• (1) The enclosure contains apparatus, such as switches, circuit breakers, fuses, relays, or resistors that may produce arcs, sparks, or temperatures that exceed 80 percent of the autoignition temperature, in degrees Celsius, of the gas or vapor involved in normal operation.
  Exception:
  Seals shall not be required for conduit entering an enclosure under any one of the following conditions:
  • (1) The switch, circuit breaker, fuse, relay, or resistor is enclosed within a chamber hermetically sealed against the entrance of gases or vapors.
  • (2) The switch, circuit breaker, fuse, relay, or resistor is immersed in oil in accordance with 501.115(B)(1)(2).
  • (3) The switch, circuit breaker, fuse, relay, or resistor is enclosed within an enclosure, identified for the location, and marked “Leads Factory Sealed,” or “Factory Sealed,” “Seal not Required,” or equivalent.
  • (4) The switch, circuit breaker, fuse, relay, or resistor is part of a nonincendive circuit.

If it is an LED light, then it will have a driver in the enclosure which will have resistors and built-in fuses on the circuit board within the assembly. BUT if the enclosure is sealed from the factory, identified as such, and rated for Class 1 Div 1, then it would fall under exception (3) and no seal off would be required.

 

[DBill64]

Also of note: it is not just arcing and sparking that is a concern, but also temperature. 501.15(A)(1)(1) states: "that may produce arcs, sparks, or temperatures that exceed 80 percent of the autoignition temperature, in degrees Celsius, of the gas or vapor involved in normal operation.".

So even if the "apparatus" does not arc or spark, if it can reach temperatures in excess of 80% of the autoignition temperature (of whatever fume/gas being protected against) then it would also require sealing (if none of the exceptions applied).