230.8 interpretation

[102 Inspector]

An inspector in a neighboring jurisdiction has interpreted that any service that has an underground supply from the POCO needs to have a raceway seal provided. The typical set-up is underground riser to meter base, then panel board connected back to back with short nipple. He is now requiring that the short nipple be sealed to prevent moisture, condensation and/or insect and rodent entering the panel board. Currently under 2008 edition and nothing in commentary really explains the intent. Can someone provide me with their thoughts on the application of this section? Graphics would be great. As an inspector in a neighboring jurisdiction, we try to stay consistent, just not sure if he is applying it correctly.

 

[infinity]

The nipple is required to be sealed. We've been sealing them with duct seal on one side (usually the panel side) for over 20 years.

 

[ptonsparky]

We seal as well. One of the few things I see our inspector actively look for.

 

[wwhitney]

230.8 as written seems a bit weird. It starts (2011) "Where a service raceway enters a building or structure from an underground distribution system . . ."

Why should the need for sealing the raceway depend on whether the OCPD is inside the building or outside the building?

[Edit: I see that 225.27 covers this for feeders, so it needs sealing regardless.]

Cheers, Wayne

 

[al hildenbrand]

An inspector in a neighboring jurisdiction has interpreted that any service that has an underground supply from the POCO needs to have a raceway seal provided. The typical set-up is underground riser to meter base, then panel board connected back to back with short nipple. He is now requiring that the short nipple be sealed to prevent moisture, condensation and/or insect and rodent entering the panel board. Currently under 2008 edition and nothing in commentary really explains the intent. Can someone provide me with their thoughts on the application of this section? Graphics would be great. As an inspector in a neighboring jurisdiction, we try to stay consistent, just not sure if he is applying it correctly.

If your neighboring jurisdiction had cited 2008 NEC 300.7(A) for the nipple seal, it'd been clearer, in my opinion. "Raceways exposed to different temperatures" is the broad brush rule.