reccessed light ko sealing? classified area

[JJWalecka]

Reccesed fixture within 3' of door is in the classified area.
Its a class 1 division 2.

A KO was knocked out of the ffixture and needs to be plugged.

What's the correct way?
A 1/2 threaded hub with a 1/2 explosion proof threaded ko seal?
Or a seal off and compound?

 

[don_resqcapt19]

An explosion proof fixture housing will not have knock outs. There is no need for a special seal to close the knock out and there is no need for the seal off on the conduit entry.

 

[weressl]

Reccesed fixture within 3' of door is in the classified area.
Its a class 1 division 2.

A KO was knocked out of the ffixture and needs to be plugged.

What's the correct way?
A 1/2 threaded hub with a 1/2 explosion proof threaded ko seal?
Or a seal off and compound?

A Div. 2 rated fixture usually is a 'temperature limited' fixture. As opposed to the XP (Div.1) rated fixture, where only the temperature of the external 'envelope' of the fixture is need to be in compliance, a Div. 2 fixture needs to meet the AIT temperature limitation internally as well as externally. This means that the fixture itself is not designed to withstand an internal explosion, therefore its openings do not to be closed with devices that meets the XP rating. A simple threaded plug should suffice.

 

[JJWalecka]

Thanks for your feedback gentleman

An explosion proof fixture housing will not have knock outs. There is no need for a special seal to close the knock out and there is no need for the seal off on the conduit entry.

The pic shows (barely) that a 1/2 threaded hub is installed in the bottom of the picture.
So if i understand a simple threaded KOseal in tthe hub is all that is required?

 

[JJWalecka]

Reccesed fixture within 3' of door is in the classified area.
Its a class 1 division 2.

A KO was knocked out of the ffixture and needs to be plugged.

What's the correct way?
A 1/2 threaded hub with a 1/2 explosion proof threaded ko seal?
Or a seal off and compound?

With the fixture within the 3 foot classified location. Does the fixture in the picture need an explosion proof KO seal?

 

[rbalex]

With the fixture within the 3 foot classified location. Does the fixture in the picture need an explosion proof KO seal?

What purpose would it serve?

 

[JJWalecka]

What purpose would it serve?

The fixture is sealed inside the spray booth. The back of the fixture, ajacent to the classified area isn't. A seal off is provided coming out of the fixture because its within three feet of the door.

I want to seal the fixture properly. Wouldn't a regular KOseal allow vapors into the nback of the fixture??

 

[rbalex]

...
Wouldn't a regular KOseal allow vapors into the nback of the fixture??

Yes, but so would an explosionproof seal. An explosionproof seal on a non-explosionproof enclosure is useless; e.g., the seal shown in the OP photo.

 

[JJWalecka]

Yes, but so would an explosionproof seal. An explosionproof seal on a non-explosionproof enclosure is useless; e.g., the seal shown in the OP photo.

So the fixture shown should be explosion proof because the backside is within the 3 feet of the opening.

 

[rbalex]

So the fixture shown should be explosion proof because the backside is within the 3 feet of the opening.

Not necessarily, but it must meet the requirements of Section 501.130(B)(1). An explosionproof fixture is one way, but not the only way to meet the requirements. If it does meet those requirements but is not explosionproof; no explosionproof seals are required (or useful) for the fixture enclosure.

Any openings must still be closed as required by Section 110.12(A). If the fixture is required to be explosionproof under Section 501.130(B)(1), then unused openings must be closed by both Sections 110.12(A) and 500.8(E)(3).