Remote distribution panel or subpanel?

[Marc D. Shunk]

Originally Posted by rwilcox

Thank you for your opinion.

It's not an opinion. It's a statement of fact. I'm starting to feel like I'm casting my pearls before swine.

[Paul W. Abernathy]

Originally Posted by Marc D. Shunk

In the past, when I've addressed the entire photograph, I get blasted for providing too much information. Now, I only address one portion, and I get "but... also...". I have no idea which set of rules to follow.

Join the crowd

[Greg Fretwell]

Jeff 225.38(B) and (C) get misunderstood sometimes

(B) Simultaneous Opening of Poles. Each building or structure disconnecting means shall simultaneously disconnect all ungrounded supply conductors that it controls from the building or structure wiring system.
(C) Disconnection of Grounded Conductor. Where the building or structure disconnecting means does not disconnect the grounded conductor from the grounded conductors in the building or structure wiring, other means shall be provided for this purpose at the location of disconnecting means. A terminal or bus to which all grounded conductors can be attached by means of pressure connectors shall be permitted for this purpose.

It says the disconnect shall open all ungrounded conductors (B) and if it doesn't open the grounded conductor it is OK to open that in the busbar in the main panel by pulling the wire off. (C)
I can't imagine a scenario where that would not be true. I suppose you could CadWeld the connection to the service ungrounded connection but I can't imagine anyone doing it. 225.38 says don't do that.
In a practical sense why would you really want to disconnect the ungrounded conductor in normal situations? It would only be done for diagnostic reasons as far as I can see.
It is also pretty easy to find parallel grounding paths. Look at what is bonded in the far panel. The normal things would be a metal raceway or metal plumbing. If you didn't install a grounded Dmark/TVSS on TV, LAN and phone at the far building they are not parallel paths. From a surge protection standpoint that is probably a bad idea but if you live in a place where that is a minor issue it probably won't be done.

[cbuell]

I count "six" ground wires connected to the neutral/ground bar and "six" wires entering the panel (including the wire feeding the panel). This indicates to me that it is a "four-wire feed. The neutrals and grounds need to be isolated and the panel needs to be bonded. Harry-homeowner hard at work

[rwilcox]

Marc, do you like pig sausage?

[Larry D. Kage]

Originally Posted by cbuell

I count "six" ground wires connected to the neutral/ground bar and "six" wires entering the panel (including the wire feeding the panel). This indicates to me that it is a "four-wire feed. The neutrals and grounds need to be isolated and the panel needs to be bonded. Harry-homeowner hard at work

That's what I see too.

It looks like the remote panel feed grounging conductor is located directly above where its grounded conductor is terminated. It is a little hard to tell sizewise but the count is correct.

[David P. Valley]

Originally Posted by cbuell

I count "six" ground wires connected to the neutral/ground bar and "six" wires entering the panel (including the wire feeding the panel). This indicates to me that it is a "four-wire feed. The neutrals and grounds need to be isolated and the panel needs to be bonded. Harry-homeowner hard at work

Thank you. That's why I asked...

What's up with the grounds?

[Michael Larson]

Originally Posted by Marc D. Shunk

I was only addressing one matter, which was the 3-wire feeder. In the past, when I've addressed the entire photograph, I get blasted for providing too much information. Now, I only address one portion, and I get "but... also...". I have no idea which set of rules to follow.

Marc, Paul and any other electricians who are kind enough to come on this BB,

Please continue to share code citations as I and others find the references helpful.

I see nothing wrong with giving the code reference as long as a layman's explanation is also provided.

The codes are a great resource for the home inspector even if we are not code officials. If one understand the reason behind the code he can be a better inspector IMO.

[Marc D. Shunk]

Originally Posted by cbuell

I count "six" ground wires connected to the neutral/ground bar and "six" wires entering the panel (including the wire feeding the panel). This indicates to me that it is a "four-wire feed. The neutrals and grounds need to be isolated and the panel needs to be bonded. Harry-homeowner hard at work

It doesn't matter if it happens to be fed with 4-wire. There is nothing that would compel a person to seperate the grounds in a panel in a detached structure with no other metallic paths. A 'subpanel' needs a 4 wire feed with grounds and neutrals seperated except when that load side panel is in a detached structure with no other metallic paths. Simple as that. Calling it out would be irresponsible in this case, if there happen to be no other metallic paths between the two structures. If there are, or you can't tell, calling it out might be prudent. Otherwise, there's no violation. Seperating the grounds and neutrals would be totally optional in that case.

I'd be more concerned with whether that type NM cable that's feeding that panel is pulled in an underground conduit. I'd be more concerned with what appears to be a missing bond screw or strap. I'd be more concerned with what appears to be a missing grounding electrode system. I'd be more concerned with what appears to be at least one sorely overfilled conduit. I would not be a bit concened about a 3-wire feed to a detached structure with no other metallic paths.

Oh, on the subpanel rhetoric, Jeff... the NACHI SOP happens to use the word subpanel.

[Jeffrey R. Pope]

Here is what I'm referring to Greg (bold is mine)

250.32 (B)(2) Grounded Conductor. Where (1) an equipment grounding conductor is not run with the supply to the building or structure, (2) there are no continuous metallic paths bonded to the grounding system in both buildings or structures involved, and (3) ground-fault protection of equipment has not been installed on the common ac service, the grounded circuit conductor run with the supply to the building or structure shall be connected to the building or structure disconnecting means and to the grounding electrode(s) and shall be used for grounding or bonding of equipment, structures, or frames required to be grounded or bonded.

Originally Posted by Marc D. Shunk

Oh, on the subpanel rhetoric, Jeff... the NACHI SOP happens to use the word subpanel.

That certainly doesn't make it right.

The use of the word "subpanel" is fine, as long as everyone is on the same page, which is rarely the case with home inspectors. Do a search on this forum (or any other HI Elec forum for that matter) and you'll see hundreds of examples where there is confusion - the original post in this thread is a prime example.

I've read posts stating things like "this is a picture of the main service subpanel," or, "the main disconnect located in the subpanel." Or my favorite, "can the grounds and neutrals be connected at the main supanel?"

There's a simple solution - stop using a term that causes confusion. If it is not "service" equipment, it must be "other" equipment. If it's not a "service panel," it must be an "other panel."

[Jeffrey R. Pope]

Originally Posted by Marc D. Shunk

It doesn't matter if it happens to be fed with 4-wire. There is nothing that would compel a person to seperate the grounds in a panel in a detached structure with no other metallic paths.

What say you then, to this?

250.24 (5) Load-Side Grounding Connections. A grounding connection shall not be made to any grounded circuit conductor on the load side of the service disconnecting means except as otherwise permitted in this article.

See 250.32 for connections at separate buildings

(referenced in my above post)

[Paul W. Abernathy]

Which is why I would prefer to see it called

Sub-Panel = Remote Distribution Panel
Main Panel = Service Panel or Main Distribution Panel

Makes it easier when teaching......but thats just me......personally the use of Sub-Panel does not bother me as long as they understand the concepts that are involved with it clearly.

Sure you can have a OCPD in a "Remote Distribution Panel" and to be honest that is just what it is....an overcurrent protection device which is probably redundant in basic cases because of the OCPD located in the "Service Panel " or " Main Distribution Panel"......in fact we hardly ever use MLO panels just because of the cost....I can usually get Service Panels that have the ability to also be " Remote Distribution Panels" for a bit less....guess it is supply and demand.

In regards to the 230.32(B)(2) statement.....this is VERY hard for a HI to determine in an routine inspection...hell it can be hard enough in a municiple inspection but sometimes we find it......take the example of my brother I use in my seminars.......he wont talk to me these days because of a violation I called out when filling in for a AHJ.....he had tried to use 230.32(B)(2) yet in the trench he also had structured wiring between the buildings and a concrete walkway with rebar...all of which presented a PATH that would not allow 230.32(B)(2).....so I failed him.....and thus we have not talked since...

BUT this was during a municiple inspection...not a home inspection.....so it is very hard to determine if this rule is being applied.....what I would concern myself with is if the detached facility has the proper bonding and grounding associated with it.......

I know when I visited the ITA school in Manassas,VA I was sitting in and they got to that section and point blank said you MUST have a 4 wire setup to a detached garage....and anything else was a violation of the code.....and in no uncertain terms......while I did not agree I spoke up and explained all the in's and out's......obviously to the dismay of the instructor but it needed to be spoken.

[Marc D. Shunk]

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[tdietrich1]

Originally Posted by Marc D. Shunk

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tom

[Paul W. Abernathy]

Originally Posted by Marc D. Shunk

It doesn't matter if it happens to be fed with 4-wire. There is nothing that would compel a person to seperate the grounds in a panel in a detached structure with no other metallic paths. A 'subpanel' needs a 4 wire feed with grounds and neutrals seperated except when that load side panel is in a detached structure with no other metallic paths. Simple as that. Calling it out would be irresponsible in this case,

Marc,

I think you know this...but as being compelled.....not seperating them in a "remote distribution panel" that was done with 4 wires would create a parallel path.....if installed as a 3 wire setup to a detached structure in 250.32(B)(2) would allow....

IN the above the " metallic paths " are the reason that 250.32(B)(2) can't be done.....so in running 4 wires and NOT being compelled to separate them would be a direct violation of 250.32(B)(2) in a technical sense.



This subsection added a new requirement and it reads:

(B) Grounded Systems
(2) Grounded (neutral) Conductor. Where (1) an equipment grounding conductor is not run with the supply to the building or structure, and (2) there are no continuous metallic paths bonded to the grounding system in both buildings or structures involved, and (3) ground-fault protection of equipment has not been installed on the common ac service, the grounded circuit conductor run with the supply to the building or structure shall be connected to the building or structure disconnecting means and to the grounding electrode(s) and shall be used for grounding or bonding of equipment, structures, or frames required to be grounded or bonded.

The size of the grounded conductor shall not be smaller than the larger of:
(1) That required by 220.22 (maximum unbalanced neutral load), or
(2) That required by 250.122 (equipment grounding conductor size). Figure 250–10

Intent: The new sentence specifies how to size the grounded (neutral) conductor to a building or structure, when an equipment grounding conductor is not run to the separate building or structure.

Author’s Comment: When an equipment grounding conductor is not run to a separate building or structure, the grounded (neutral) conductor must be used to provide the effective fault current path required to clear any line-to-case faults in addition to carrying any unbalanced neutral current.

P.s...those are Mr. holts comments...not mine...