Class 1 Division 1 seal fitting location for explosion proof pressure transmitter

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All,
Can you tell me by attached files, if i am on the right path for seal fitting placement. Or does the seal fitting need to go on the vertical line, above transmitter? Thanks in advance!
David
 

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Strathead

Senior Member
Location
Ocala, Florida, USA
Occupation
Electrician/Estimator/Project Manager/Superintendent
All,
Can you tell me by attached files, if i am on the right path for seal fitting placement. Or does the seal fitting need to go on the vertical line, above transmitter? Thanks in advance!
David


I may be wrong, but it seems to me the best approach would be to have an intrinsically safe barrier for the wires, then you wouldn't need a seal at all, except where the conduit left the classified area.
 

kwired

Electron manager
Location
NE Nebraska
More detail is needed before we can tell if a seal is even needed, but if one is where you have it will be fine, actually it would need to be before the tee fitting so I don't see it could go in the vertical run.
 
kwired,
What other detail would you need? I am curious. This installation is going in a class 1, div. 1 area. Please let me know what other information I need to provide.

More detail is needed before we can tell if a seal is even needed, but if one is where you have it will be fine, actually it would need to be before the tee fitting so I don't see it could go in the vertical run.
 

kwired

Electron manager
Location
NE Nebraska
Transmitter details, is it intrinsically safe? It is there arcing parts in it? It may not need a seal depending on some information you may find about it. Maybe you have already determined it does need a seal - IDK.
 
kwired,
Thank you for the clarification. All I can see from the spec sheet is that it is explosion proof. So, I am assuming that I need a seal. Thanks again!

Transmitter details, is it intrinsically safe? It is there arcing parts in it? It may not need a seal depending on some information you may find about it. Maybe you have already determined it does need a seal - IDK.
 

kwired

Electron manager
Location
NE Nebraska
kwired,
Thank you for the clarification. All I can see from the spec sheet is that it is explosion proof. So, I am assuming that I need a seal. Thanks again!
Going from memory here, but AFAIK the need for a seal is only needed when the item in question contains components that ordinarily create ignition sources - like switches or contactors. Otherwise boundary seals are the next level of sealing that is needed.

If a seal is needed it must be within 18 inches with only limited items such as explosion proof unions, reducers or capped elbows being the only thing between the seal and the enclosure requiring seal.
 
kwired,

I do thank you for your time and enlightening me. I appreciate it. Keep up the good work!
David

Going from memory here, but AFAIK the need for a seal is only needed when the item in question contains components that ordinarily create ignition sources - like switches or contactors. Otherwise boundary seals are the next level of sealing that is needed.

If a seal is needed it must be within 18 inches with only limited items such as explosion proof unions, reducers or capped elbows being the only thing between the seal and the enclosure requiring seal.
 

Strathead

Senior Member
Location
Ocala, Florida, USA
Occupation
Electrician/Estimator/Project Manager/Superintendent
Going from memory here, but AFAIK the need for a seal is only needed when the item in question contains components that ordinarily create ignition sources - like switches or contactors. Otherwise boundary seals are the next level of sealing that is needed.

If a seal is needed it must be within 18 inches with only limited items such as explosion proof unions, reducers or capped elbows being the only thing between the seal and the enclosure requiring seal.

My understanding is similar to kwired's. But I think that the splice point is what you have to be concerned with. The transmitter shouldn't need any type of seal, but the wiring will need to be enclosed and isolated from the gasses. Many of those transmitters are provided with threads, and you can run conduit and a splice box, but I have done an installation where, there is an intrinsically safe barrier outside, and the wiring runs in conduit sealed at the class 1 boundary. Then it went to A GUAC box and there was a cable gland with the cable free aired in to it. The splicing was done with butt splices in the box.

It was about four years ago so I hope I'm not remembering wrongly.
 
Thank you very much for the information Strathead!

My understanding is similar to kwired's. But I think that the splice point is what you have to be concerned with. The transmitter shouldn't need any type of seal, but the wiring will need to be enclosed and isolated from the gasses. Many of those transmitters are provided with threads, and you can run conduit and a splice box, but I have done an installation where, there is an intrinsically safe barrier outside, and the wiring runs in conduit sealed at the class 1 boundary. Then it went to A GUAC box and there was a cable gland with the cable free aired in to it. The splicing was done with butt splices in the box.

It was about four years ago so I hope I'm not remembering wrongly.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
It is my opinion that neither the transmitter nor the enclosure containing the splice is required by 501.15(A) to have a seal fitting.

One related item. The OP needs to verify that the transmitter complies with 501.17.
 
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