seal offs

[earlejohnson]

Was wondering if anybody could tell me, what they know about underground conduit work on top of an old city landfill? Engineer says, "every pipe that is in the dirt needs to have a seal off on both ends." Is this true? Even the mains coming into the MDP, although on the other side going into the transformer it's open. If so could you point me to the right place in the code book to reference this? This is my first post, hopefully of many. Just wishing I knew more. Thanks.

 

[wireguy8169]

Needs

Needs

Did he say needs to by code or needs to cause they want it? Never had to deal with that sounds interesting, wonder if it has anything do do with methan and the possiblity of it getting into the conduit and then to the equipment ect... When you do find out I would be interested to know whats up.

 

[earlejohnson]

it is for "methan"

 

[arits74]

i used to work for a large city municipality close to here and the shop was built on top of part of the old landfield,the cracks in the concrete slab let enough mathane gas in that you could light it on fire,the shop was moved a while back

 

[augie47]

I have seen more than one incident where landfill methane has caused switchgear explosions so the potential is definitely present.
If you are the contractor/electrician for the job I would suggest you follow the engineering specs and allow him to assume the liability for the engineering. The inspector will normally check the same specs.

{That said, you might look at Exception 2 to 501.15(B)(2)}

 

[weressl]

I have seen more than one incident where landfill methane has caused switchgear explosions so the potential is definitely present.
If you are the contractor/electrician for the job I would suggest you follow the engineering specs and allow him to assume the liability for the engineering. The inspector will normally check the same specs.

{That said, you might look at Exception 2 to 501.15(B)(2)}

I would not install anything related to Article 500 unless the area classification is clearly documented, defining the Class, Division, specific gas or source of ignititon defined and the AIT. It is an OSHA requirement, so if this is not available to you then somebody is breaking the law.

Nobody can and should demand that you install something that you do not understand. 'Following orders' has its dire consequences.