# seal offs at light fixtures



## Tom45acp (Sep 6, 2011)

Typical of so many engineers, trying to weasel out of doing his job.

If the area is classified as Div 1 or Div 2, then restricted breathing doesn't appear to be an issue. As far as I can tell, restricted breathing only comes into play if you're doing the zone method in article 505 and only for zone 2. See table 505.9(C)(2)(4). That is the only reference that I could find in a quick look in the NEC. I don't know what it really means or why it would be used.

Good luck.


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## mm11 (Sep 14, 2012)

I looked at the spec sheet for the fixtures, and it shows the nR technique for only the Zone classification, not for the Class and Division classification.

The fixtures are classified C1, D2, and seal-offs are required when entering explosionproof enclosures [501.15 (B)(1)], which these type of fixtures are not. Not that it means anything, but all the pictures in the spec sheet show no seal-offs. 

Also, it may be possible that the fixtures are hung high enough to be out of the C1, D2 area altogether.


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## buddhakii (Jan 13, 2011)

mm11 said:


> I looked at the spec sheet for the fixtures, and it shows the nR technique for only the Zone classification, not for the Class and Division classification.
> 
> The fixtures are classified C1, D2, and seal-offs are required when entering explosionproof enclosures [501.15 (B)(1)], which these type of fixtures are not. Not that it means anything, but all the pictures in the spec sheet show no seal-offs.
> 
> Also, it may be possible that the fixtures are hung high enough to be out of the C1, D2 area altogether.


Thanks for pulling the up the spec sheet on that. The thing is is that the fixtures are hung high enough to be out of the exp area. A note on the prints state that the exp area is 10 feet from the gas seperators but the entire basement must be wired for class 1 div 2. I know I don't need them but I'm having an issue proving that to the engineer. I really need to though because it will be a b##ch to install these as requested. I'm still not sure what the restricted breathing is all about so if someone could enlighten me I would appreciate it.


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## denny3992 (Jul 12, 2010)

Methanes density is .6 which means its lighter than air, i would think they should have seal offs

Working in wwtp... Its a great idea as h2s is also terrible on elec equip and any attemp to keep the gases out is great! Also apply a coating to lamp base ( like noalox) before instAlling them


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## SteveBayshore (Apr 7, 2013)

Also apply a coating to lamp base ( like noalox) before instAlling them[/QUOTE]

Don't use noalox on the lamp base; the heat from the lamp bakes it and it dries out= stuck bulb. Been using "Bulb Ez" for a few years in water/waste water treatment plants and at Jersey Shore locations. It comes in a little plastic container about half the size of a roll of tape for a few bucks. Some type of wax based stuff. (bulbez.com)


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## denny3992 (Jul 12, 2010)

SteveBayshore said:


> Also apply a coating to lamp base ( like noalox) before instAlling them


Don't use noalox on the lamp base; the heat from the lamp bakes it and it dries out= stuck bulb. Been using "Bulb Ez" for a few years in water/waste water treatment plants and at Jersey Shore locations. It comes in a little plastic container about half the size of a roll of tape for a few bucks. Some type of wax based stuff. (bulbez.com)[/QUOTE]

Ive used vasoline in the past... Eek


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## SteveBayshore (Apr 7, 2013)

Ive used vasoline in the past... Eek[/QUOTE]

Yea, the new apprentices always wanted to know why all of the trucks had a big jar of vasoline in the glove compartments.:whistling2:


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## denny3992 (Jul 12, 2010)

SteveBayshore said:


> Ive used vasoline in the past... Eek


Yea, the new apprentices always wanted to know why all of the trucks had a big jar of vasoline in the glove compartments.:whistling2:[/QUOTE]

Not that theres anything wrong with that...


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## htneighbors (Jan 23, 2009)

What is the classification of the location where the fixtures are installed? 
What method? PVC Coated Rigid? Rigid Steel? LFMC? Cable Tray? 
What is the model number of the fixtures? VMV? DMV? FMV? 
What type mounting? Pendant? Wall? Stanchion? 
Really need more info to prove your case. 

Restricted Breathing is a method of construction for an enclosure such that the possibility of entry of a surrounding explosive gas or vapor atmosphere is reduced to a low level. The design includes a very high level of sealing which limits the possible entry of flammable gas or vapors.

It seems the suffix S828 is specifically for the "Restricted Breathing" location...this below is from their literature. If you also have the S865 option, these are factory sealed and no external seal would be required. 

The following special options are available from the factory by
adding suffix to luminaire Cat. No.:​Description Suffix​• Restricted Breathing Construction...................................​​​​S826‡​
Class I, Division 2 & Zone 2 Suitability​Cooler Operating Temperatures (T-Numbers)


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## buddhakii (Jan 13, 2011)

It is cl1 div2 location. I based my not installing them due to the fact that in cl1 div2 locations you are basically required seal offs in two locations. First is when going from classified location to different classification. The other is when entering an explosion proof enclosure. It is obvious these lights do not contain the ballast in an explosion proof enclosure, so in order for them to get the listing to be installed in this location then and explosion proof enclosure is not required therefore a seal off is not required. I opened a fixture up yesterday and it says on the inside that all components are rated to be installed in a cl1 div2 location. The last thing I sent to the inspector was basically you prove to me that I need them.


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## htneighbors (Jan 23, 2009)

That ought to work! I'm interested in his reply. Keep us posted.


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