Electrical Substation and NFPA 497

[ksavoie]

Is there any rule in the NFPA that will not allow for an Electrical substation with positive pressure ventilation in a Class 1 Div 2 area, within 40 feet from a gas heater?

 

[rbalex]

There are basically three NFPA documents (70, 496, and 497) that collectively address your question.

Assuming NFPA 497 was the Standard used to determine the electrical area classification and NFPA 496 was the Standard used to design/maintain the pressurization of the substation, NFPA 70 (the National Electrical Code) would permit the installation you have described.