Wire depth

[johnpm]

I would like your opinion on this. We have been working on a subdivision entrance way lighting
project. The lights are 120V 6AMP total. The circuit is protected by a GFI breaker. The
disagreement starts in 300-5. The AHJ says this wire must be 18in. deep. I told him it
should be under 300-5 column 4.(residential branch circuit). He said it's not residential.
I asked him " What is the classification". He said " It's a common area." After this I called NEC public affairs. They initially agreed with AHJ, but upon closer review said this circuit
is under 300-5 column 4. What do you guys think
of this?

 

[charlie]

Re: Wire depth

The reason for the lesser depths for dwelling units is the lack of digging depth normally done around a home. At a subdivision entrance, all kinds of things can go on. We (IPL, not a government body, or an AHJ) have always considered that type service as commercial. The same logic would apply to a community building, a pump for a pond, tennis court lighting, etc.

 

[johnpm]

Re: Wire depth

Thanks for the response.We hit rock, that's The reason we came up to 12in. This property is zoned
residential. We had to pull residential permits.
I asked the AHJ where is this located in the code book,he said " I don't know, we've been using the 18in. rule for 15 yrs."

 

[johnpm]

Re: Wire depth

Does anyone else have an opinion on this? I can
see Charlie's point. Keep in mind this is a 120V
15A circuit. Also it's not in the right of way.
If this is not covered under 300-5 column 4,
where is it covered. Thanks for the help

 

[russ]

Re: Wire depth

You got me thinking.

What constitutes a residential circuit.
Comeing out of a dwelling and staying on private property, or coming out of some public panel (location unknown) and runing on public property.
There are more possibilities, but these seem to be the most likely to happen.

My first reaction is it's not residential.

Russ

 

[jxofaltrds]

Re: Wire depth

John

Why are you saying this is a residential branch circuit? Where is it fed?

Give us more details. Please.

Mike P.

 

[johnpm]

Re: Wire depth

This circuit is coming from a 100A ML panel,that is attached to a rock column. This column is on
the edge of a "residents" lawn. Therefore, the
circuit is not on commercial property.

 

[don_resqcapt19]

Re: Wire depth

John,
Who pays the utility bill for this circuit?
Don

 

[johnpm]

Re: Wire depth

The home owners assoc. I guess. The service hasn't
been energized yet.

 

[russ]

Re: Wire depth

John:

I never asked, how is the circuit run.
Cable, RMC, Plastic?

 

[johnpm]

Re: Wire depth

It is cable. There is conduit coming from the ground to the boxes. Remember this is not a feeder
cable.

 

[roger]

Re: Wire depth

John, this seems to be a case of between a rock and a hard place. In reality I would consider this anything but a residential circuit.

If I were doing this, I would run IMC or RMC regardless of finding a loop hole in the code.IMHO

Roger

 

[johnpm]

Re: Wire depth

Don't get me wrong. I am not looking for a loophole. I just want the AHJ to show me (in the
code book) where I am wrong.

 

[russ]

Re: Wire depth

I guess if this was Monday night football, we'd be waiting for the instant replay, wondering how the Referee is going to see it.

I,m betting on 18", it's just the way I see it.

Note 5 of table 300.5 describes what you have to do if you hit solid rock.

Russ

 

[johnpm]

Re: Wire depth

I noticed note 5 also. That is why we came up to
12in.(to avoid rock). There is still a question:
What is a residential branch circuit. I can find
the definition of branch circuit(in the code book)
But I can't find residential.

 

[stamcon]

Re: Wire depth

I don't see a definition for "residential" only for "dwelling", but 210-25 states that common area branch circuits can't be supplied by a dwelling unit. If it not being supplied by a "dwelling unit", can it be callled a "residential branch circuit"?

 

[gwz2]

Re: Wire depth

I would think that if the circuit does not originate from a dwelling unit service/panelboard and as per 210.25 then would be a deciding factor.

Also, since the service does not supply a dwelling,
310.15(6) would not be applicable.

 

[johnpm]

Re: Wire depth

Both of these posts have valid points.But where( in the code book) does it say,that a common area
circuit is not a residential branch circuit. If
this property was commercial,I could understand
the division.

 

[charlie]

Re: Wire depth

As I stated before, I think the property is commercial since no one lives in the common area. Additionally Glenn, in Indiana, this installation would not be covered since this is not a Class 1 or a Class 2 structure.

 

[johnpm]

Re: Wire depth

I can see your point. But if this area is commercial, it would be zoned commercial and not
residential. The permits we received were residential not commercial.