Seal off locations

DAWGS

Senior Member
Location
Virginia
We are running rigid conduit from a cable tray that runs along a gas pipeline. We are coming off the tray to underground and will pop up at a combustion skid that is classified class 1 div 2. We will install a seal coming up out of the ground at the skid, and another seal at the control cabinet penetration. Do we need a seal coming up at the cable tray? This is not in a bermed tank area. 501.15(B)(2) exception 2?
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
Is the cable tray actually in a classified location; that is, is there a definite boundary between the conduit stub up and the cable tray?
 

DAWGS

Senior Member
Location
Virginia
Is the cable tray actually in a classified location; that is, is there a definite boundary between the conduit stub up and the cable tray?
I would say Yes, that part of the tray is what I believe in a div 2 area. Its running on the same rack as the gas piping
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
Just going off other projects with engineered drawings that would classify the pipe racks as class 1 div 2.
The requirements of Section 500.4 always come first.
500.4 Documentation.

Areas designated as hazardous (classified) locations or determined to be unclassified shall be documented on an area classification drawing and other associated documentation. This documentation shall be available to the authority having jurisdiction (AHJ) and those authorized to design, install, inspect, maintain, or operate electrical equipment at the location.
Depending on your NEC edition, the wording may be slightly different, but the intent is still there.

In order to answer the original question, the boundaries must be identified correctly.

NOTE: It's not usually necessary to classify a pipeway but that depends on several factors. See 500.5 (B)(2) IN No.2.
 
On the website, go to Killark form No. K0983. Read the whole document. On page 3 near the bottom, it talks about how to close up the enclosure. But, above that, it talks about how to pry open an enclosure. Read. Read. Read. I am constantly learning and I never take it for granted that I know everything. Over the 45 years as an electrician, I am surprised at how many journeymen never read any paperwork. I have been on sites that none of the explosion proof seal offs are not even poured. I see cord connector bodies with the wrong rubber cord grommet on the cord and the sealing gaskets upside down and not aligned with the tabs and indents.
 
Top