Is this screwed on lug approved for GEC

[redikillowatt]

New home construction (in county - no inspectors) w/ a new Cutler-Hammer 200 A service entrance (residential).
No other sub panels.

This panel has separate ground buss - shown in pics. I assume the (split) neutral & ground buss are bonded together, but didn't take a pic.
1) If the neutral & grd buss must be directly bonded, what size conductor is required for 200 A load center?

Pics show one GEC connected to a lug, screwed to panel box. Another (2nd) GEC is connected to ground buss.

One GEC goes to what was someone's intention to be a Ufer grd (but isn't). It's only 3/8" rebar, & slab has plastic vapor barrier under & up side of slab.

2nd GEC goes directly from panel to a driven 8 ft galvanized rod.

2) Does NEC allow using a lug screwed to the panel for a GEC, or should all GECs (if more than one) be connected to ground buss? It would seem for a GEC, there needs to be more contact than a screw through sheet metal. Although the box is grounded, that set up is dependent on the box being part of the grounding path - to & thru the GEC.

Thanks.

 

[hurk27]

Assuming when you mentioned that this is a service panel that it contains the service disconnect, then it is allowed to land the GECs in this panel, but they must be connected to the grounded service conductor by a buss, or wire not a screw, so yes you are correct that they should have been landed on the neutral bar not a ground bar that is only connected to the grounded neutral bar via screws, the GEC that is in the single lug is also a violation. (250.24(A)(4)

It also appears that the GEC landed in the ground bar has been trimmed down to fit the smaller terminal, also a violation.

 

[redikillowatt]

Thanks hurk27,
It is the only service entrance panel (not a sub panel) & it has the ONLY main breaker. Here, they don't use separate disconnects between the meter & load center (service panel).

Given that, should the separate grounding buss (bottom of pic, w/ green screws) be bonded w/ proper conductor, bonding strap, etc., to neutral buss?
If no strap is supplied to bond neutral & grounding buss, there must be a min. size bonding conductor for 200 A service?

they [GECs] should have been landed on the neutral bar not a ground bar that is only connected to the grounded neutral bar via screws

If so, should the GECs (in this case, 2) be landed on: ONLY the NEUTRAL buss where the grounded service conductor connects? Or allowable to land GEC on the grounding buss, * IF * grounding buss is (or should be) bonded to neutral buss? Or does it matter which buss, if they're bonded - in a main disconnect panel like this?

This CH panel has split neutral buss - on each side of panel. W/O looking again, don't remember if both split busses have lugs for grounded service conductor.
If only one grounded service conductor lug, I'd assume the GEC should be connected on that side - of a split neutral buss.

Re: trimmed GEC. I don't know if they trimmed it or strands just got bent. I'll look closer to see if they actually cut off strands. I believe the ? lower ? terminal on Neutral & probably grounding buss take larger wire. Looks like GECs are # 4, or #6. They might have to twist stranded a bit to get it in, but they should fit. They haven't set breakers or connected service conductors yet.

 

[hurk27]

It can be left on the ground buss if you run a #4 to the neutral bar, but it doesn't look like the GEC's will fit in the holes of that ground buss, I found a great add a lug, that has a fork to go under two terminals in a buss bar to allow for larger wires to be connected to it, Menard's here carries them, I believe they are made by CH and are hanging by the CH panel parts, the single lug is a violation and has no way to bond it via a wire back to the neutral bar, it should be landed at the neutral bar of if jumper is installed to the grounding bar, the jumper is sized from the table 250.66

As for the split neutral bar, since it has a bus bar that connects the two halves the GEC can land on either side.

 

[redikillowatt]

Thanks for the idea about the "add a lug." I'll have to inspect closer to see if either the neutral or grounding buss have holes large enough for # 4. Solid would be a bit easier to get in.

It would be common to use # 4 GEC - yes? Wouldn't it also be common to land a GEC on the grounding buss, when one is installed? Why wouldn't CH make it so it'd handle larger GEC conductors, unless this electrician just used what was on the truck?

Or on newer panels like this, are GEC(s) more often landed on neutral than grounding buss?

One side question: GECs aside, if a grounding buss is added like this one, is bonding it to neutral buss required, other than connection via both being screwed to the panel? In many earlier main disconnect panels (say 30 yrs ago), the neutral & ground busses were made as one unit.

 

[hurk27]

Thanks for the idea about the "add a lug." I'll have to inspect closer to see if either the neutral or grounding buss have holes large enough for # 4. Solid would be a bit easier to get in.

No problem

It would be common to use # 4 GEC - yes? Wouldn't it also be common to land a GEC on the grounding buss, when one is installed? Why wouldn't CH make it so it'd handle larger GEC conductors, unless this electrician just used what was on the truck?

It's not what is common but the size required by table 250.66
, as for the size of the terminals,
I wished they would go back to those older buss bars that had one large terminal for every three small ones, those were great, ITE and Square D both supplied the grounding bars installed on MB panels, and an extra large lug that fit on the buss bar for larger conductors, but wasn't installed, it was in the bag with the MBJ screw or panel cover screws, but they all offer lugs for larger conductors for their neutral/grounding bars, most of the bars I see will barely take up to a #8 or #6, a #4 will require larger lug, the bars in your photo's look like factory bars, as the screws lined up with the holes in the back of the panel.

Or on newer panels like this, are GEC(s) more often landed on neutral than grounding buss?

While it is very common for a main service panel to land both the EGC's and the GEC's on the main neutral buss, more and more panels are being shipped with grounding busses installed where the panel has a main breaker, and for the life of me I can't figure out why those same companies do not supply one with a main lug panel where you have to have one? this has never made any sense to me, so many times I will save them from the main breaker panels, and use them in a main lug panel, they are not needed in a main breaker panel when it is used as service equipment.

One side question: GECs aside, if a grounding buss is added like this one, is bonding it to neutral buss required, other than connection via both being screwed to the panel? In many earlier main disconnect panels (say 30 yrs ago), the neutral & ground busses were made as one unit.

250.28(A) allows screws for the main bonding jumper which is the path for EGC's so yes EGC's can be terminated to a grounding bar mounted by screws without a jumper, only GEC's are required to be a buss bar or wire found in 250.24(A)(4) so they can not be landed to the grounding bar that only has screws attaching it to the panel.

 

[redikillowatt]

Thanks very much for the clear replies. Makes sense. Need to take another close look at the panel. I think I can convince them to do it right.

Re: sizing GEC based on service conductor sizes. If my research is correct, there are exceptions to 250.66 for GEC sizing.
For "made" electrodes (driven rods, etc.) GEC is not required to be > 6 awg Cu, or # 4 Al.

For CEE, a GEC is required to be at least a # 4 Cu.
For ground rings, the GEC is required to be at least # 2 Cu.

Was this a typo:

250.28(A) allows screws for the main bonding jumper which is the path for EGC's so yes EGS's can be terminated to a grounding bar mounted by screws without a jumper

Did you mean EGCs or electrical generating systems / suppliers?

 

[hurk27]

Thanks very much for the clear replies. Makes sense. Need to take another close look at the panel. I think I can convince them to do it right.

You need to copy down those code sections that I have posted, and have a code book handy then go over it with your electrician so he can see your concerns, just because you are in an area that does not have inspections does not relive you or your electrician from following the code, and or the liability when something goes wrong and someone is hurt or killed.

Re: sizing GEC based on service conductor sizes. If my research is correct, there are exceptions to 250.66 for GEC sizing.
For "made" electrodes (driven rods, etc.) GEC is not required to be > 6 awg Cu, or # 4 Al.

these are not exceptions but different allowances for different installations of different types of grounding electrodes, for the bonding jumper as it would be required just as main bonding jumper (I think) then it should have to follow 250.28(D) which says we have to use table 250.66 which for 2/0 or 3/0 service wire size would be a #4

For CEE, a GEC is required to be at least a # 4 Cu.
For ground rings, the GEC is required to be at least # 2 Cu.

Was this a typo:

Did you mean EGCs or electrical generating systems / suppliers?

Yes I meant EGC's I edited after you saw it.

 

[gndrod]

Hi Redikillowatt,
Some of the questions you have asked leave concern for convincing an electrical sub on how to do the installation correctly. A general contractor must rely on the EC to set the UFER bonding and make sure that the slab is not isolated from the hardpan prior to a concrete poured turned footing.

Maybe a second opinion from another EC would help build confidence in getting a compliant installation.

 

[jaggedben]

What the original installer could have done with that GEC going to the lug is pass it through the lug and then bring it to the ground bussbar. If you remove that GEC from the lug you will need to ensure that the enclosure is bonded in some other manner, though that's probably obvious to you.

What the original installer also could have done, although I'm sure some here will frown on it, is split the strands of the GEC going to the ground bussbar and put it into two holes. While it might violate something (maybe 110.3), it would certainly have been better than not terminating all the strands of the conductor in the bar, which is what appears to have been done. Hurk's forked lug suggestion is no doubt more legit.

 

[redikillowatt]

Thanks again.

hurk27 - I will have the codes & general scope written down - thanks for citing them. Short of buying a copy of NEC, are there ways to get actual excepts for specific codes? It's possible an electrician on the job may understand the errors, but even the EC may not interpret the specific codes correctly. Face it, NEC often has ambiguous language. If it comes to it, I'll either get another EC or an inspector (I suppose out of his jurisdiction) to back me up. You're correct about the liability.

Re: Allowances or exceptions for GEC sizing. I was going by articles like this from Mike Holt forum & from other sites.
http://www.mikeholt.com/mojonewsarc...ding-versus-Bonding-Part-7-of-12~20050302.php

Using Table 250.66, size the GEC for the largest service-entrance conductor (or equivalent area for parallel conductors-unless the GEC connects to one of the three following electrode types:

Ground rod. That portion of the GEC that is the sole connection to the ground rod does not need to be larger than 6 AWG copper (Figure 250-122 [not included] ). Follow the ground rod installation requirements contained in 250.52(A)(5).
Concrete-encased grounding electrode (Ufer ground). That portion of the GEC that is the sole connection to the concrete-encased electrode does not need to be larger than 4 AWG copper (Figure 250-123 [ not included] ). Follow the concrete-encased electrode installation requirements contained in 250.52(A)(3).

Below is a pic of a Siemens 2 prong lug. Note: says ONLY for ground bar, which would mean if GEC is landed on ground buss, it must be bonded to neutral buss, as you said.

Gndrod - absolutely correct. As mentioned, they failed at the attempt for a Ufer ground. Now, to meet code, they'd have to put one outside the slab. That might be a better ground than say, 2 driven 8 ft rods. A problem w/ Ufer grounds in the humid south is, they always put heavy plastic under & up sides of footers of slabs. Many interpret that as violating requirements of Ufer grounds.

Jaggedben - there should be a factory bonding strap from enclosure to neutral buss. I'll check. If the GECs won't fit either neutral / grounding buss, I'd probably prefer a lug like hurk27 suggested. I'd guess the reason they screwed on a larger lug is they had trouble getting the other GEC though grounding buss terminal. Depending on the specific ground bar, many specs say "Bar wire holes are suitable for (1) #14?4 or up to (3) #14?10 aluminum or copper wire," May well be larger terminal(s) on neutral buss.

From Eaton Cutler-Hammer load centers product description. There are 2 types of split neutral buss load centers:

Factory Bonded Split Neutral
Certain single-phase main circuit breaker panels are supplied with a factory-bonded twin neutral. When used as a sub panel, the bonding strap
should be removed, and the bonding screw should be reinstalled. The bonded side is now the ground, and the un-bonded side is the neutral. When used as a service entrance panel, the unused neutral holes on either side may be used for terminating ground wires.

Insulated Split Neutral
Most single-phase panels (12 circuits and greater) are supplied with a twin neutral with an insulated cross strap. These panels are shipped in an un-bonded state. For service entrance applications, the neutral must be bonded utilizing the bonding strap supplied with the panel. For sub-feed applications, the panel may be installed as is. Separate ground bars are provided on these panels.

 

[redikillowatt]

Took closer look at the CH panel. Of course, it has 2 large terminals on one of the split neutral buss to use for a GEC (plus the terminal for service conductor). The other split neutral has at least one large terminal. So they had plenty of other options - maybe didn't have enough # 4 wire on the truck.

Re: reference to NEC 250.24(A)(4) from earlier reply.

only GEC's are required to be a buss bar or wire found in 250.24(A)(4) so they can not be landed to the grounding bar that only has screws attaching it to the panel.

Reading a quote & discussion of that code on this forum - http://www.mikeholt.com/mojonewsarchive/GB-HTML/HTML/NECArticle250Sections250.20-250.34~20020124.htm
It says in part:

grounding electrode conductor can terminate to the equipment grounding terminal to which the main bonding jumper is connected

Regarding the GEC that the electrician landed on the extra lug that was just screwed to the panel, I've read many times that the panel / enclosure / "can't be used as a conductor" (or part of the grounding electrode conductor). The GEC is supposed to terminate to the neutral buss (thus connected to the grounded service conductor), or to an equipment grounding bar, if that bar is properly bonded to the neutral buss.

Which NEC section mentions that the GEC can't be terminated to the enclosure (sheet metal) or that the enclosure can't be used as part of the path for the GEC?

It's clear that the GEC must be continuous (unbroken) from the main disconnect to the grounding electrode, but I'd like something to give the EC that specifically forbids terminating the GEC to a lug that is only screwed to the panel, or other code that, by requiring the GEC to ONLY be terminated to the neutral buss or a grounding bar properly bonded to neutral buss, would prohibit terminating it to a screwed on lug, as shown in attached photos.

Though I knew from the start it wasn't correct, it's not clear to me which codes specifically prohibit them using the lug screwed to the panel to terminate the GEC. When I get my camera connected, I'll post pic showing entire panel & supplied (2) bonding straps, which they didn't connect - yet.

 

[hurk27]

Which NEC section mentions that the GEC can't be terminated to the enclosure (sheet metal) or that the enclosure can't be used as part of the path for the GEC?

It's not that it can't be terminated to the enclosure but that the connection between the grounded conductor and grounding electrode conductor cant' be through a screw.

250.24(A)(4) Main Bonding Jumper as Wire or Busbar. Where the
main bonding jumper specified in 250.28 is a wire or busbar
and is installed from the grounded conductor terminal
bar or bus to the equipment grounding terminal bar or bus
in the service equipment, the grounding electrode conductor
shall be permitted to be connected to the equipment
grounding terminal, bar, or bus to which the main bonding
jumper is connected.

Which gives us permission if a wire or busbar is between the two then and only then can we land the GEC on the grounding bar.

 

[redikillowatt]

I believe I understand your last reply & the code cited just fine. I'm not sure you understood my question - or maybe I'm mixed up.

but that the connection between the grounded conductor and grounding electrode conductor cant' be through a screw.

Meaning, the connection of the GEC to the service ground conductor can't be through a screw. GEC has to be connected directly to neutral bar where service ground is, or can be connected to a ground bar terminal, IF that ground bar is bonded to the neutral buss w/ proper wire or strap.

But in my last post, I wasn't asking if GEC could ever be connected to the grounding bar (equipment grounding terminal) -if it's properly bonded to neutral buss. I was asking what code(s), by specifically limiting where a GEC could be attached (like, ONLY to neutral buss, or an equipment grounding bar that's bonded to neutral buss), therefore eliminating screwing a lug directly to the panel sheet metal (as shown in pic), w/ GEC attached to it. That GEC is ONLY screwed to sheet metal panel.

250.24(A)(4) talks about bonding the equipment grounding terminal to neutral buss, THEN allowing GEC connection to equipment grounding terminal (bar).

I believe NEC requires the GEC to be unbroken between where it (legally) attaches in main disconnect panel and to the grounding electrode.