seal offs

Status
Not open for further replies.
K

ktollar

Member
We have a enclosed tank with a dome top. Inside of this tank is sludge influent before it has been treated.
( Sewage Plant) There could be amounts of methane inside of this tank. We also have mixing motors inside of this tank. The mixing motors have a factory cable that is rated for the classification.
The electrical contractor installed a 1" flex from the top of the dome to a disconnect on the handrail surrounding the dome. Inside of this sealtight they installed the motor factory cable. At first he claimed that he did not need a seal off and then he installed a 1" seal off. The diameter of the factory cable is about 5/8". I have explained that the seal off is required per code and that it should be installed per 1999 nec 501-C 3, & 6.
What do you think?
 
The inside of the tank is definitely a Class 1 location. [Edited from hereon... again... after rereading your post... again.] Need more details surrounding the penetration and how it is performed. Does it permit inner tank atmosphere to permeate into the sealtight? If yes, it is in violation.
 
Last edited:
Additional question: Why should it be installed per 1999 NEC? It's currently 2006 and generally the 2005 version is used... ;)
 
Apparently not. I only have to deal with compliance in my little corner of the world, which is mostly east to northeast Ohio. That gets expanded a bit into PA and WV when work is harder to come by.
 
Projects around here are usually to code in effect at the time permits are pulled or a plan is approved, whichever came first.
 
Status
Not open for further replies.
Top