Class 1 Div 2 Location

[glamp]

The last sentence of 511.3 states. "A class 1 location shall not extend beyond an unpierced wall, roof, or other solid parition that has no openings."

511.3 (E) (1) says adjacent areas can be unclassified "where effectively cut off by walls or partitions." Does this mean that the walls or partitions are required to be unpierced and have no openings as stated in 511.3 in order to be unclassified?

 

[Smart $]

I take "effectively cut off" to be equivalent to "unpierced and have no openings" between the areas of consideration.

 

[weressl]

The last sentence of 511.3 states. "A class 1 location shall not extend beyond an unpierced wall, roof, or other solid parition that has no openings."

511.3 (E) (1) says adjacent areas can be unclassified "where effectively cut off by walls or partitions." Does this mean that the walls or partitions are required to be unpierced and have no openings as stated in 511.3 in order to be unclassified?

Correct, with the caviat that you are allowed to pierce that barrier with transition fittings or other similar devices that will effectively prevent the passage of gas from one area onto the other.