Electrical Cabinet Placement in Class 1 Div 1

[Forqnc]

Hi, we had a customer recently tell us their company paid for NFPA to come on their site to confirm their classification zones.
They informed us that they where told if an electrical cabinet, with a Class 1 Div 2 rated HMI, is installed 6ft away from the opening of were flammable chemicals are added to their process and the cabinet is purged protected that area is a Class 1 Div 2 which makes the electrical cabinet ok to be there?
I've looked through section 5 but nothing jumps out at me about a 6ft spacing and classification change.
Any assistance is appreciated.

 

[don_resqcapt19]

Often they use the "bubble" method of classification, which could explain the 6' distance. With the "bubble" method, the classified area is a bubble around the flammable vapor source.

I hate projects where they do this, in place of classifying the whole room, as it results in a lot more boundary seals.

As far as the purge and presentation of the cabinet, that is a permitted protection method. See 500.7(D) and NFPA 496, Standard for Purged and Pressurized Enclosures for Electrical Equipment.

 

[Forqnc]

Thank you for the reply Don.