Cable Seals, & 501.15(E)(1)

[Dale001289]

501.15(E)(1)
(1) Terminations. "Cables entering enclosures that are required to be explosionproof shall be sealed at the point of entrance. The sealing fitting shall comply with 501.15(B)(1) or be explosionproof. Multiconductor or optical multifiber cables with a gas/vaportight continuous sheath capable of transmitting gases or vapors through the cable core that are installed in Division 2 location shall be sealed with a listed fitting after the jacket and any other coverings have been removed, so that the sealing compound can surround each individual insulated conductor or optical fiber tube in such a manner as to minimize the passage of gases and vapors…"
My understanding is, third sentence (red letters) simply qualifies cable type as it applies to explosionproof enclosures - only. Some interpret this to mean ALL multiconductors must be sealed, regardless of type termination/enclosure in Class I, Division 2 locations.
Comments?

 

[rbalex]

The qualifier is in the first sentence: "Cables entering enclosures that are required to be explosionproof ..."; i.e., it is when a cable seal is required. The last sentence is how to seal it, if required.

​

 

[AKElectrician]

The qualifier is in the first sentence: "Cables entering enclosures that are required to be explosionproof ..."; i.e., it is when a cable seal is required. The last sentence is how to seal it, if required.

I have seen where they want the outer jacket sealed (MC). Then the belden type wire inside some cables have a gas block installed. Was told the terminator seal is to stop transmission through the MC portion of the cable, the gas block was used to keep the gas from transmitting through the belden wire from inside the outer plastic coating the mylar and wires. Was used for instrumentation, they didn't want the mylar removed to limit noise could collect in the boxes they were installed in. Only time I have seen gas blocks used is on belden type wire though.

 

[rbalex]

Section 501.15(E) is for cable sealing requirements in Class I, Division 2.

While some manufactures may claim otherwise, no NRTL certifies any cable core except Type MI as “gas-blocked”. There is no recognized test to determined it for an unspecified length.

The NEC doesn’t require any cable type that is suitable for Class I, Division 2, to have the cable sealed at the terminations except when it enters an enclosure that is required to be explosionproof, which, of course, could apply to many instruments.

 

[AKElectrician]

Section 501.15(E) is for cable sealing requirements in Class I, Division 2.

While some manufactures may claim otherwise, no NRTL certifies any cable core except Type MI as “gas-blocked”. There is no recognized test to determined it for an unspecified length.

The NEC doesn’t require any cable type that is suitable for Class I, Division 2, to have the cable sealed at the terminations except when it enters an enclosure that is required to be explosionproof, which, of course, could apply to many instruments.

Correct. That took care of the MC portion. The twisted pair (belden) was covered by 501.15 (E) (1) Exception 2. At least how I understood it.

 

[nec_addicted]

Correct. That took care of the MC portion. The twisted pair (belden) was covered by 501.15 (E) (1) Exception 2. At least how I understood it.

Actually there is a test it is printed in 501.15(E)(2) and cables that do not transmit gases or vapors that are Available as metal clad cl 1 div 1 or div 2 normally used in Nuclear industry. In AK we used them from Okonite during early 1990 time frame. That is when the gas blocking kits were approved at the end inside the enclosure close to the union fitting after the seal there were also same gas blocking kits used between class 1 div 2 and unclassified areas near the 10 foot rule sometimes even on the unclassified side since we had to tent and warm up to pour conduit seals but that is kind of off the subject. I have forgotten since we stopped use in the 2000 year time frame.

Previously about 35 years ago we tested the type of MC cables that meet the 501.15(E)(2) (now days not as as in 1990 code) value lengh of cable stated in this article is assessed as 0.007 cubic feet perhr at a pressure of 1500 pascals (6 in of water) during our testing in Valdez AK was performed. The test apparatus I use to have the drawings but I am betting underwriters or possible other NRTL would have a listing.

 

[nec_addicted]

501.15 (E)(2)

501.15 (E)(2)

Abstract:
The National Electrical Code (NEC) provides for reduced sealing requirements on-multiconductor cables in Class I hazardous locations when the cable has a gas/vapor-tight continuous sheath and will not transmit gases or vapors through the cable core. The new cables that comply with this requirement are discussed, together with the reduced sealing requirements and the testing procedure to verify compliance of the cable with the gas/vapor blocking requirements.
Published in: IEEE Transactions on Industry Applications ( Volume: IA-19, Issue: 3, May 1983 )
Page(s): 430 - 433
Date of Publication: May 1983
ISSN Information:
DOI: 10.1109/TIA.1983.4504219
Publisher: IEEE
Sponsored by: IEEE Industry Applications Society
http://ieeexplore.ieee.org/document/4504219/

 

[rbalex]

Nec_addicted, rather than your usual attempt to baffle with ..., provide a recognized standard that provides a test that allows NRTL certification. I'm well aware of the history.

 

[nec_addicted]

Cable Seals

Cable Seals

In true technical Bob is correct about two things. First off no offense taken here at HOlts gem. Secondly the rule in 501.15(E)(2) does not include the leakage rate of the inner stices between conductors. The idea was more about the online cable seals inOkoniete CLX 105 degree rated cable where some parity was intended as well an process switch listed and hermetically sealed with less than 18" multiconductor pigtails and quality process designers have attained 501.17 of which Bob knows about vastly more than any historian might mention would qualify as different than MI Cable used as an example about no NRTL that would be the vertible delima in no NRTL or test supported but to be fair previous in that questionable .... It is worthy explanation I was under the assumptions everybody might see the absolute vanish for a consideration at a maybe.
In closing I thought the digital library IEEE Explore might have the approved test in the foundation I did not have from 1983 in the pages listed in that questionable post. All in all it should suffice there are exception to almost any form of a rule or bizarre code cloud but I am accustomed to explaining with support from National Organizations where difference of thought might be an impartial theory about an Only phrase.

 

[nec_addicted]

Cable Seals

Cable Seals

The previous post directly above should have been written in the lead in sentence where "interstices leakage rate between stranded conductors..." are not recognized as producing explosive variable volume gas dangers of explosion below #2 AWG.

It might be since 4160 V feeders or UG service conductors, the smallest multiconductor available for purchase cable begins with #2 AWG and moves up the rated current carrying capacity based on temperature and applied to NEC article 326. Integrated Gas Spacer Cable (IGS) . There those multiconductor UG services are very hard to obtain and use except outdoors where natural ventilation is allowed to become the barrier to leakage of SF6. Whatever we all have slept since then and things have changed for the safer national recognized standard testing.

 

[nec_addicted]

Cable Seals- NRTL

Cable Seals- NRTL

(1) double vent seals as 501.17 effective to bleed off gas and cable going from Cl 1 Div 2 to Unclassified, (2) A hermetically sealed apparatus, (3) A MI Cable . All three examples of the topic of conversation as I recall the discussion in this thread.
http://www.cooperindustries.com/con...iterature/redapt-threadconversion-catalog.pdf
http://literature.rockwellautomation.com/idc/groups/literature/documents/wp/800-wp003_-en-p.pdf

 

[rbalex]

(1) double vent seals as 501.17 effective to bleed off gas and cable going from Cl 1 Div 2 to Unclassified, (2) A hermetically sealed apparatus, (3) A MI Cable . All three examples of the topic of conversation as I recall the discussion in this thread.
http://www.cooperindustries.com/con...iterature/redapt-threadconversion-catalog.pdf
http://literature.rockwellautomation.com/idc/groups/literature/documents/wp/800-wp003_-en-p.pdf

If you believe that, you should probably reread the OP.

 

[nec_addicted]

Cable Seals & Explosion Proof OP was removed and changed to 501.15(E)(1)

Cable Seals & Explosion Proof OP was removed and changed to 501.15(E)(1)

The removal of the OP or maybe not was what threw my thinking off. Same type subject them gravitated and I commented this might not correspond but off subject and I did apologize for whom ever declared to limit the subject matter to one specific article.Maybe was the best thing to do however I believed the OP had been developed to where it was interesting how it narrowly contorted into a constriction of freedom to improve the options.

 

[GoldDigger]

The removal of the OP or maybe not was what threw my thinking off. Same type subject them gravitated and I commented this might not correspond but off subject and I did apologize for whom ever declared to limit the subject matter to one specific article.Maybe was the best thing to do however I believed the OP had been developed to where it was interesting how it narrowly contorted into a constriction of freedom to improve the options.

?????

Sent from my XT1585 using Tapatalk

 

[nec_addicted]

Cable seal

Cable seal

The intent was to explain this thread started out as primarily 501.15(B) discussion. That was the prelude to which sentence out of the three was the intent of seals if required at explosion proof enclosures. The two quotes (some in red sentence) still here in this thread had already posted about eight comments discussion about 501.15(B) when suddenly the first 5 or 6 comments were dropped and the main thrust of clarification gravitated to 501.15(E)(1).

The title took on the meaning that 501.15(E)(1) was the only topic of subject.I know this to be true because I started a post of the former but forgot to complete it but sending post reply. Consequently those permitted time was not allow and when going back in to recapture the original discussion it no longer was available because it was deemed best practice to restrict discussion to 501.15(E)(1). Almost immediate the inline cable seals were shot down when posted by Ak electrician. Then I turned a phrase 501.15(E)(2) as a viable alternative. All was fine until the end I was requested to read the OP which was under the impression no longer available to read so recover it or accept the discussion as is now that's my point of view.

 

[AKElectrician]

You lost me a long time ago nec_addicted.
The installation I mentioned where a seal and a block were used in a case of a cable terminator seal for the boundary seal and the gas block for the twisted type wire covered with mylar. Unclassified area had control cabinet, installed MC-HL single pair ran to J box in class 1 div 2 location. Installed boundry seal for cable and gas block for twisted pair. Had power in J box, so left mylar and black sheath on and gas blocked it close to term blocks. No arky no sparky no need for explosion proof box. I did it the way I was told, by AHJ. Made sense to me.