Main Breaker interlock

[mjgilmore54]

Has anyone failed inspection using a main breaker interlock kit for a generator install. I have heard some inspectors have not allowed them on the grounds that if someone removes the panel cover
there is no more protection aganist backfeeding the utility grid.Thanks for any info.

 

[M4gery]

You can find a way to make any transfer switch backfeed the grid with your own generated power if you take a screwdriver and mess with it.

 

[Smart $]

Has anyone failed inspection using a main breaker interlock kit for a generator install. I have heard some inspectors have not allowed them on the grounds that if someone removes the panel cover there is no more protection aganist backfeeding the utility grid.Thanks for any info.

Typically not involved with inspections, so can't offer any input there.

As to disapproval, perhaps a stretch, but reasoning is sound and within scope of authority.

 

[Smart $]

You can find a way to make any transfer switch backfeed the grid with your own generated power if you take a screwdriver and mess with it.

I disagree (i.e. without using the screwdriver as a conductor).

 

[iwire]

As to disapproval, perhaps a stretch, but reasoning is sound and within scope of authority.

In my opinion this would require a written amendment to the NEC, not just the whim of the AHJ.

I disagree (i.e. without using the screwdriver as a conductor).

I think the basic point is that you can't stop people from screwing things up and inspectors should not be enforcing 'what ifs'

 

[Smart $]

In my opinion this would require a written amendment to the NEC, not just the whim of the AHJ.

I completely agree for an optional interlock that is part of the panelboard manufacturer listing. Any other interlock is completely subject to AHJ approval without ammendment, IMO (even though the design may be identical to a manufacturer listed one).

I think the basic point is that you can't stop people from screwing things up and inspectors should not be enforcing 'what ifs'

You can stop people from screwing up to a degree, but otherwise I agree it is impossible to make anything completely foolproof.

I did say "perhaps a stretch", did I not? Inspecting must take some 'what ifs' into consideration. One example, determination of 'subject to physical damage'. Many Code requirements force the AHJ to ask the 'what ifs'... and yes, they sometimes go a bit too far!!!

 

[M4gery]

I think the basic point is that you can't stop people from screwing things up and inspectors should not be enforcing 'what ifs'

Yes, thank you.

I included a screwdriver into my post just as an example of how no one can do this by mistake, it's not something a kid could accidentally do, etc. The only way the panel cover is coming off is if someone knowingly takes it off.

The AHJ failing the OP seems to be similar to banning televisions because someone can unscrew the back cover and get shocked or burned.

 

[stew]

How many homeowners do you know that would actually take the cover off? Most are to scared of electricity to do so. And if properly fitted with a proper device what reason would a homeowner have to remove the cover? This sounds like an inspector I know in my area that always is trying to fail something on what if scenerarios. If it is not to code on inspection then fail it. Otherwise keep your dang mouth shut Mr. inspector!

 

[Cow]

In my opinion this would require a written amendment to the NEC, not just the whim of the AHJ.



I think the basic point is that you can't stop people from screwing things up and inspectors should not be enforcing 'what ifs'

For the record I agree with you, but aren't "what if's" the reason we now need handle ties on MWBC's?

 

[M4gery]

For the record I agree with you, but aren't "what if's" the reason we now need handle ties on MWBC's?

Handle ties on MWBC, much like ballast disconnects and neutrals in all switchboxes, are yet another addition to the code to keep people who don't know what they are doing safe.