boundary for classified area

[Jeff-b-f]

I remember that there are allowances in the code to downgrade the classification of an area beyond certain distances. I can't find the section of the code that refers to this.
Specifically, you can transition from Cl I Div I to Cl I Div 2 beyond an imaginary boundary. Could you direct me to the relevant code?

 

[rbalex]

Re: boundary for classified area

Actually it isn't an allowance; it is a requirement and it is found in Section 500.5(B)(2)(3).

The theory is that, if there is a Division 1 location (may be hazardous under normal operating conditions), a location immediately adjacent to it must have ignitable materials occasionally under abnormal conditions.

However, except in certain specific applications such as Articles 511 to 516, the NEC does not specify the limits of either the Division 1 or 2 boundaries. You must go to an independent document such as NFPA 497 or API RP500 to determine the boundaries. References to similar documents are found in the FPNs to 500.4(B)


Edit: Corrected reference to 500.5(B)(2)(3).

[ March 02, 2006, 10:17 AM: Message edited by: rbalex ]

 

[jafro]

Boundary of Classified Area

Boundary of Classified Area

Hi Guys:
In Canada only an "Engineer" can classify an area and if you want to change or revise the boundaries he imposes (part of his assesment )you better get it in writing from him or hire an engineer to do a new assesment.
Electricians do not classify or alter area classifications which include boundaries
Jafro