Open face spray booth

[codeunderstanding]

In 516.3(c)2 On a open face spray booth used for wood sealing applications is the 3 foot verticle encompass just the area on top of the booth from the face or the entire top of the booth? If so would the wiring method supplying the lights on top of booth need to be classified?

Would the area behind the booth where the exhaust motors are that vent outdoors be a unclassified area?

 

[rbalex]

Re: Open face spray booth

References are from the 2005 NEC.

Figure 516.3(B)(2) generally applies to your question. What may not be clear is that it actually has two parts, the upper 3 illustrations and the lower 3. The difference in application is the method of interlocking the spray application with the ventilation system.

From the Figure there is a 3 foot radius from each opening, similar to the statement in 516.3(B)(4) and shown in its Figure.

The 3 foot radius will not necessarily cover the entire top of the booth and there would be a 3 foot ?bubble? around the fan exhaust.

A note of caution: also check 516.7(B) as it affects the light fixtures. They do not necessarily need to be identified for classified locations but do need additional mechanical protection.

 

[codeunderstanding]

Re: Open face spray booth

In 516-3b2 they have a class II division2 location for a choice there. How would that work for spray booths when class II is for combustible dusts?

 

[rbalex]

Re: Open face spray booth

Articles 511 through 517 are largely extracted from other NFPA documents. In the case of Article 516, it is NFPA 33 and Figure 516.3(B)(2) is taken from NFPA 33, Figures 6.5.2(a) and 6.5.2(b).

Basically, the Technical Committee that controls NFPA 33 has decided to treat the exterior of the booths the same, no matter what the ?Class? is.