maintenance of haz area equip

[gareth0127]

having moved from a work location using UK/EN atex standards to one using NEC standards I am struggling to find guidance on the repair of electrical enclosures.

1. If I have an explosion proof enclosure (Class I Div 1) in a Class I Div 2 area do I have to still ensure that it still meets the standards for which it was designed? E.g undamaged flamepaths?

2. I have an enclosure in a class I div 2 area that appears to be explosion proof but has no markings. To what level should it be maintained and what repairs are acceptable? Note that the enclosure does not contain an arcing equipment.

Im confident that I would take the correct repair options for atex regs but would not be so sure using the NEC so would appreciate any thoughts.

 

[petersonra]

1. If I have an explosion proof enclosure (Class I Div 1) in a Class I Div 2 area do I have to still ensure that it still meets the standards for which it was designed? E.g undamaged flamepaths?.

Only if for the application an XP enclosure is required. Many times in Div 2 areas XP enclosures are not required.

2. I have an enclosure in a class I div 2 area that appears to be explosion proof but has no markings. To what level should it be maintained and what repairs are acceptable? Note that the enclosure does not contain an arcing equipment.

Same answer as question number 1.

I am suspicious of a lot of XP installations. I have seen more than a couple where the box has been damaged, maybe by being hit by something like a forklift, or by chemical agents in a couple cases.

As far as I am concerned, I do not think it is within the realm of normal field repairs to do much in the way of actual repairs to an XP box. Maybe replace an O-ring if it has an O-ring seal. Maybe basic cleaning.

But, i don't think there is any way to actually field repair them, if for instance the mating surfaces no longer match up correctly.

 

[gareth0127]

thanks Bob, I think what you say at the end more clearly demonstrates what I mean eg if the flamepaths do not correctly mate but it is an a Div 2 area do I need to change the box? Or is it enough to ensure the box is sealed? I assume the NEC would advocate maintaining equipment to whatever standard it was designed for, regardless of loacation, and I woukd also encourage this, but I cant find any info to confirm this

 

[petersonra]

The NEC does not much care what the equipment was designed to do as long as it is suitable for what it actually has to do.

Whether a damaged XP box is still suitable for a division 2 area in an application that does not require an XP box is a bit of a gray area in my mind.