516.3 vs engineer

[augie47]

I have encountered an interesting situation. One jurisdiction where I am employeed accepts a letter from a registered engineer to be accepted in leiu of a UL or NRTL listing.
A plant in that area installed a paint spray room aong with a mix room and other equipment, some of which had no listing or labeling. An engineer was hired and asked to "certify" the equipment and to classify the Hazardous area. There are electrical components installed on the outside of the booth
within inches of a roll- up door. These cocponents are in a NEMA 1 enclosure.
The engineer says "no problem, since there is a door".


Not that it matters since the AHJ accepts his letter as final word, but is my thinking correct that the engineer is (gawd forbid) wrong based on:


From 2005 NEC"
"516.3 Classification of Locations:
(C) Class I or Class II, Division 2 Locations The following spaces shall be considered Class I, Division 2 or Class I, Zone 2, or Class II, Division 2 as applicable.
(4) Enclosed Booths and Rooms For spraying operations confined to an enclosed spray booth or room, the space within 900 mm (3 ft) in all directions from any openings shall be considered Class I, Division 2, Class I, or Zone 2, or Class II, Division 2 as shown in Figure 516.3(B)(4). [NFPA 33:6.5.4]"

 

[ron]

NRTL doesn't inspect for compliance with the NFPA, just there own equipment standards. An AHJ or in your case an engineer can determine compliance with NFPA codes/standards.
It is very possible that he/she made a mistake, and since you might be familiar with a code section that he/she is not, it would seem that you can mention it to him/her.

 

[petersonra]

a door is not an opening. it is a door.

 

[renosteinke]

516.3 vs. engineer

516.3 vs. engineer

As a certain famous person once said, "I feel your pain."

Your reading of the code is correct; there is a 3 ft "bubble" around doors and other opening. That said.....

I have seen quite a few pre-fab paint booths with the same design. In the ones I've seen, though, the door has been near the fresh air entry, with the exhaust section quite distant from the door.
Likewise, the stuff that's sprayed varies greatly in it's flamability. Some processes, like powder coating and epoxies, may not create a hazardous location at all. Even the most volatile have far fewer fumes than once was the case.

Of course, having an engineering degree, or even a PE license, is no guarantee that the engineer has any idea as to the subject. The 2008 ROP has a proposal that will replace the term "professional engineer" with "qualified party" for this sort of judgement call.

The final call may be made by the customers' insurance carrier. Until then, you're pretty much stuck with an 'iffy' layout. It's the PE's license- he wants to take the risk, let him.

 

[dlhoule]

As a certain famous person once said, "I feel your pain."

Your reading of the code is correct; there is a 3 ft "bubble" around doors and other opening. That said.....

I have seen quite a few pre-fab paint booths with the same design. In the ones I've seen, though, the door has been near the fresh air entry, with the exhaust section quite distant from the door.
Likewise, the stuff that's sprayed varies greatly in it's flamability. Some processes, like powder coating and epoxies, may not create a hazardous location at all. Even the most volatile have far fewer fumes than once was the case.

Of course, having an engineering degree, or even a PE license, is no guarantee that the engineer has any idea as to the subject. The 2008 ROP has a proposal that will replace the term "professional engineer" with "qualified party" for this sort of judgement call.

The final call may be made by the customers' insurance carrier. Until then, you're pretty much stuck with an 'iffy' layout. It's the PE's license- he wants to take the risk, let him.

How will this "qualified party" be defined?

 

[kingpb]

renosteinke,

Could you provide more insight on this so I can check it out. Frankly, I can't see this holding up.

I'm sure I can get my dog qualified in something. She is pretty smart and all.

 

[dlhoule]

renosteinke,

Could you provide more insight on this so I can check it out. Frankly, I can't see this holding up.

I'm sure I can get my dog qualified in something. She is pretty smart and all.

kingpb: I was originally going to say she could qualify to be an engineer, but seeing as to how you are an engineer, I'll say she could qualify to be an inspector.