Wall munted & wired through wall class 1 div 2 sealoff?

[djmsek]

I have installed alarm strobes on a cinderblock wall inside a class 1 div 2 area. The led strobe is rated for class 1 div 2 location and i passed a rigid nipple through the wall into the back of the fixture which is mounted flush on the wall. The nipple passes through into an unclassified area. My boss wants to know where the sealling fitting is. Since there is no conduit in the classified area why would a sealoff be required?

 

[nakulak]

read article 500 very carefully, you are still going from one atmosphere to a device in another atmosphere. however, under some conditions you can put the seal off on the other side, you will have to read the section though, or maybe someone who knows can answer.

 

[djmsek]

no animals wre harmed while typing this reply

no animals wre harmed while typing this reply

thanks for the reply it looks like i'm going to put them in anyway on the unclassified side so i don't have to justify it in the future.
I must say however that your avatar is very disturbing and i am tempted to contact the American Society for the Prevention of Cruelty to Avatars.

 

[charlie]

. . . i am tempted to contact the American Society for the Prevention of Cruelty to Avatars.

LOL, I'll sign up as a witness. :grin:

 

[weressl]

I have installed alarm strobes on a cinderblock wall inside a class 1 div 2 area. The led strobe is rated for class 1 div 2 location and i passed a rigid nipple through the wall into the back of the fixture which is mounted flush on the wall. The nipple passes through into an unclassified area. My boss wants to know where the sealling fitting is. Since there is no conduit in the classified area why would a sealoff be required?

The nipple opens into the classified location.

Does the strobe require a seal or is it factory sealed?

In other words you may require a seal for both reasons.

The only 'logical' argument against a needing a seal if the non-classified area is equipped with a positive pressure ventillation, but I am not certain that everybody would agree that it is allowed by the Code.

 

[KentAT]

I had a somewhat similar installation on a prefab building that I modified, although it appeared to be a gray area.

We have a Class 1, Div 1 room housing hi-pressure natural gas metering equipment at a facility that feeds the local gas company. Other side of the wall is Div 2. There is a 12"x12"x6" Ex-P JB mounted on the inside wall (Div 1), and contains relays serving solenoids on the outside of the wall, in the Div 2 area. The mfg of the room (prefab) ran the 3/4" conduit out the side of the JB, with a union, then to an LBY, then a short nipple through the 3" thick precast concrete wall that the box is mounted on, to a GUA box w/ a sealing cover just on the outside of the wall. This was the boundary seal. (All fittings were listed for haz. locs.)

I wanted a seal in the Div 1 area for the enclosure, but I think the mfg intended for the GUA on the outside to serve as the seal for the boundary and for the inside enclosure, since it was technically within 18" (of conduit measurement) of the enclosure.

Can the original GUA serve as the required seal within 18" of the enclosure in the Div 1 area, although it was located on the Div 2 side of the boundary?

I can accept the fact that even if I had a seal on the inside instead, there will be the same amount of exposed threaded connections, etc in 10" or so of conduit/fittings in the Div 1 area so there really is no increased risk one way or the other, but I preferred to have the enclosure seal in the same rated area as the enclosure that is requiring the seal to begin with.

Am I splitting hairs, or what?

 

[weressl]

I had a somewhat similar installation on a prefab building that I modified, although it appeared to be a gray area.

We have a Class 1, Div 1 room housing hi-pressure natural gas metering equipment at a facility that feeds the local gas company. Other side of the wall is Div 2. There is a 12"x12"x6" Ex-P JB mounted on the inside wall (Div 1), and contains relays serving solenoids on the outside of the wall, in the Div 2 area. The mfg of the room (prefab) ran the 3/4" conduit out the side of the JB, with a union, then to an LBY, then a short nipple through the 3" thick precast concrete wall that the box is mounted on, to a GUA box w/ a sealing cover just on the outside of the wall. This was the boundary seal. (All fittings were listed for haz. locs.)

I wanted a seal in the Div 1 area for the enclosure, but I think the mfg intended for the GUA on the outside to serve as the seal for the boundary and for the inside enclosure, since it was technically within 18" (of conduit measurement) of the enclosure.

Can the original GUA serve as the required seal within 18" of the enclosure in the Div 1 area, although it was located on the Div 2 side of the boundary?

I can accept the fact that even if I had a seal on the inside instead, there will be the same amount of exposed threaded connections, etc in 10" or so of conduit/fittings in the Div 1 area so there really is no increased risk one way or the other, but I preferred to have the enclosure seal in the same rated area as the enclosure that is requiring the seal to begin with.

Am I splitting hairs, or what?

The LBY is not XP rated therefore you are violating that conduit segment XP integrity. Should the union be not XP rated that would be the second non-compliant item.

 

[KentAT]

The LBY is not XP rated therefore you are violating that conduit segment XP integrity. Should the union be not XP rated that would be the second non-compliant item.

LBY is rated Class 1, Div 1 & 2, Grps. C, D

kent

 

[weressl]

LBY is rated Class 1, Div 1 & 2, Grps. C, D

kent

Not this one:

http://www.crouse-hinds.com/catalog/PDFS/00016.pdf

 

[rbalex]

That one is too. All of C-H’s “Short-radius capped elbows (90-deg bend),” fittings are rated for Class I, Groups C and D; Class II, Groups E, F and G; Class III.

C-H was one of the manufactures that had a habit in the past of stating their product was “UL compliant” rather than “listed.” They have cleaned up their act considerably.

Just a side note: all listed unions, no matter who the manufacturer, are generally suitable for Class I, Groups C and D; Class II, Groups E, F and G; Class III. A few are also suitable for Groups A and B, but you need to know the specific manufacturer’s applications. (UL Category Code "EBVN" is the only code "conduit unions" are listed under.)

 

[weressl]

That one is too. All of C-H?s ?Short-radius capped elbows (90-deg bend),? fittings are rated for Class I, Groups C and D; Class II, Groups E, F and G; Class III.

Right!

However, the issue is that the item shows up both in the hazardous and nonhazardous listing in the catalog without informing the user that it is an identical item to be used in both hazardous and non-hazardous areas. The designer or estimator or electrician who may try to pick the item does not have the benefit of having the UL table, attached by you, front of them. It is also inconsistent since LB fitting series is a nonhazardous.

 

[KentAT]

Maybe I should be ordering the one from the nonhazardous catalog when I get these...