Is My Boss Wrong? - Ground/Bonding Questions

[sparks77]

Need some help settling some things.

My boss is at his ?lake house? for the week fishing. He left me (a first year apprentice) and ?Steve? (my new boss for the week) to finish a small residential panel upgrade job. He?s made some questionable decisions that I don?t think are right. Thought you guys could help me, he gets VERY defensive when questioned, even when I bust out the NEC?we get inspected in 2 days and I was trying to impress my boss with a clean pass.

The situation:
SE cable (AL 2/0) drops into attic, runs to meter on back of house, then feeds the distribution panel 25? away (through crawlspace) inside the garage on the front of the house. No service disconnect at the meter or main breaker on panel. Only GEC (#6 copper) is to cold water line coming out of water heater. No grounding rods at the meter either.

The homeowner wants to add two additional 20A circuits for a new sump pump in the crawlspace, and landscape lightning in the backyard, etc. The old Cutler Hammer 150A panel was full and showing serious signs of age. We replaced it with a larger SquareD 200A panel with tons more space. Code requires a disconnect near the meter, so we replaced the old rusty meter box with a dual combination service entrance device. We?re using a 150A breaker in the dual box since we want to keep the AL 2/0 SEC, and not fish 4/0. The house is very small and wouldn?t pull 200A anyway?

Everything is installed, panel is beautifully organized, and we?ve added two ground rods at the meter 6? apart. Then Steve said, ?I forgot to add the green bonding screw in the panel.? He installed it.
???

I have 3 questions:

1. When you have a service disconnect ?upstream? (as in next to our meter) you leave the green ?bonding screw? OUT of the panel, correct? To keep neutral and ground separate? (the panel is considered a ?sub panel? now correct?) The SquareD dual combo box has its grounding and neutral terminal lugs on the same mounting bar that?s bonded to the box anyway. (250.24)(B)?? THIS is where the bonding happens, right. Am I wrong here? Steve says I am wrong.
2. Steve also says that we don?t need to run an EGC (#6 copper) from the newly installed service disconnect at the meter to the dis. panel?s ground bar, since we have the bonding screw installed in the panel?? I?m pretty sure this ground line needs to be installed.
3. We still only have one GEC, grounded to the water line. Doesn?t section 250 explain all of this? Doesn?t the distribution panel require 2 points of ground? Don?t we need to add another ground rod in the crawlspace directly behind the dis. Panel. Again, Steve says, ?No?

Sorry to vent here, I?m a little upset. I?ve been working very hard and trying to learn everything I can. Some people are just difficult to work with I guess. Or maybe I?m just being a know-it-all disrespectful punk. I tried to find the references in the NEC to show him, but the new changes in article 250 in terms of grounding/bonding are still confusing to me. If I?m wrong in my understanding, please enlighten me, I can be humble. I?ve seen it done.

I can?t believe how much there is to learn. I have developed GREAT respect for the older guys who spout out half the NEC from memory?any help is much appreciated!!!

Scott

 

[bphgravity]

1. Yes, you are correct. Leaving a bonding jumper installed in any equipment on the load side of the service disconnecting means is a violation of 250.24(A)(5) and 250.142(B) unless one of the exceptions can be met.

2. Yes, you are correct. The conductors between the service disconnecting means and the load side panelboard are FEEDERS. An equipment ground recognized in 250.118 is required.

3. Yes, you are correct. A metal underground water pipe is required to be supplemented by an additional electrode per 250.53(D)(2). Ground rods are probably your only solution at this point.

There is no requirement that a service has "two points of ground". That is a common misconception. As simply stated in 250.50, if a recognized and approved electrode is PRESENT at the structure, it must be bonded to the grounding system.

 

[George Stolz]

I am a little confused, but don't have time to read it twice before work.

You said you drove two ground rods, and then said the water pipe was the only grounding electrode - or I misread what you wrote.

If you only have a water pipe electrode, you must supplement it (250.54(C)(2)-ish) and that's usually done with a ground rod (or two, 250.56-ish).

As Bryan said, the system gets bonded once at the service, and never again downstream. If there are two bonding connections at two panels on the same building, somethings been done wrong.

Right now, the system is as safe as it will get until the EGC for the old feeder is installed. You can rededicate the old neutral as a EGC, and one of the old ungrounded conductors as a neutral, if you can refeed any 240V loads from the new service panelboard.

Good luck with Steve.

 

[ptonsparky]

Dadgumit, lost my whole post.

1. Yes

2. Yes, you need the 4th wire but it needs to be installed in the same raceway or cable, not just added. Enjoy the crawl space because I am sure you will be the one in it.

3. If the water line meets 250.52 requirements than it must be connected as stated in the same section. It is suplemented by the two ground rods. The water pipe connection would originate at the new service equipment not the sub. No, you are not required to have an additional electrode at the sub.

The way you describe the existing SE cable installation, it would not be allowed to feed the new service equipmint in this area.

Speaking as an older guy, a good share of the quotes are from the younger.

 

[EV607797]

Scott:

Is that 2/0 exisiting cable type SER or type SEU?

 

[haskindm]

Your boss may be wrong, but he is still the boss. Make sure that you understand his intentions and if you still think he is wrong RESPECTFULLY refer him to the proper section of the NEC. Ask him " It looks like the NEC requires ..... but it appears that we have done ....... Am I missing something?" Then if he "blows up" write him off as a jerk and look for another job. Most people respond better to honest questions than to criticism from their "juniors".

 

[eprice]

Scott,

Maybe I am not understanding correctly, but I think you have a conductor from the metal water line to the distribution panel inside and a conductor(s) from the ground rods to the meter/disconnect combo outside? Am I getting the right picture?

 

[jaylectricity]

Scott:

Is that 2/0 exisiting cable type SER or type SEU?

The one that doesn't have an equipment ground in it.

Your boss may be wrong, but he is still the boss. Make sure that you understand his intentions and if you still think he is wrong RESPECTFULLY refer him to the proper section of the NEC. Ask him " It looks like the NEC requires ..... but it appears that we have done ....... Am I missing something?" Then if he "blows up" write him off as a jerk and look for another job. Most people respond better to honest questions than to criticism from their "juniors".

My boss is at his ?lake house? for the week fishing. He left me (a first year apprentice) and ?Steve? (my new boss for the week) to finish a small residential panel upgrade job.

It's just for the week. The original poster was hoping to impress his boss when he got back from fishing by doing a beautiful job on this service. He is frustrated because when his real boss comes back the installation will be wrong because of his "new" boss and he will have missed his chance to show his boss what quality work he is capable of.

 

[tryinghard]

As per 250-24(A)(1) ?The connection shall be made at any accessible point from the load end of the service drop or service lateral to and including the terminal or bus to which the grounded service conductor is connected AT THE SERVICE DISCONNECTING MEANS?

Load-side grounding connections in (5) ?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 [250] article?

And part VI of 230 that is Service Equipment ? Disconnecting Means states in 230-70 ?Means shall be provided to disconnect all conductors in a building or other structure from the service-entrance conductors.?

Your new service 150A disconnect located at the meter base is the service disconnect not the meter. The bonding of the grounded conductor to the electrode conductor shall take place at the service disconnecting means only (in your situation). The electrode conductor is supposed to terminate there as well. All circuitry past the service disconnect is a feeder and needs an equipment ground NOT common with the grounded conductor (neutral).

1. If your boss installed the green screw at the 150A service main disconnect (next to the meter base) along with the electrode conductor this is correct and it would be incorrect to install these past the main. These are to common bond at the main and not the meter base. A #6 cu electrode conductor is correctly sized if it complies with 250-66(A) otherwise it needs to be #4 to/for U-fer type.

2. The circuit from the main is a feeder and does in fact require an equipment ground sized according to 250-122 your case #6. You may use a mechanical type (conduit) as described in 250-122(A) in place of the #6 though but you cannot install the bonding screw in the sub panel.

3. You do NOT have to use a water pipe for your electrode ground but you do have to bond it 250-104(A) with a #6 cu, electrodes types are qualified in 250-52 and you may use a rod, pipe or plate but you must not have more than 25ohms resistance using a ground rod resistance tester. If the feeder equipment ground is sized correctly the bonding can take place at the sub panel and not the main, in other words if your feeder equipment ground is sized from 250-66 rather than 250-122 you can put your water bond in the sub panel.

 

[infinity]

1. If your boss installed the green screw at the 150A service main disconnect (next to the meter base) along with the electrode conductor this is correct and it would be incorrect to install these past the main. These are to common bond at the main and not the meter base. A #6 cu electrode conductor is correctly sized if it complies with 250-66(A) otherwise it needs to be #4 to/for U-fer type.

Since the SE cable is #2/0 AL a #6 to the CCC would be properly sized according to 250.66.

 

[George Stolz]

These are to common bond at the main and not the meter base.

This is an interpretation - if the AHJ decides a POCO seal renders connections inaccessible, then the meterbase is prohibited from containing GEC connections. Otherwise, the meterbase can be the point at which the GES is connected to the neutral at a structure.

3. You do NOT have to use a water pipe for your electrode ground...

He does if an electrode described in 250.52(A)(1) is present at the structure, 250.50.

If the feeder equipment ground is sized correctly the bonding can take place at the sub panel and not the main, in other words if your feeder equipment ground is sized from 250-66 rather than 250-122 you can put your water bond in the sub panel.

Well, to be clear, the conductor that bonds an interior metal water piping system (that does not qualify as an electrode) is still sized to 250.66, per 250.104(A)(1).

 

[tryinghard]

This is an interpretation - if the AHJ decides a POCO seal renders connections inaccessible, then the meterbase is prohibited from containing GEC connections. Otherwise, the meterbase can be the point at which the GES is connected to the neutral at a structure.

I see this in 250-24(A)(1), but I never see these with more than two landing lugs so they can only accommodate grounded conductor in & out and not an additional GEC. I thought the GEC had to terminate at the service disconnect but I?m not seeing it now. In a situation like this (single family dwelling) I really don?t understand why a meter base is used because a meter, main would allow multiple grounding terminations as well as eliminate additional service terminations (between meter base & service disconnect).

He does if an electrode described in 250.52(A)(1) is present at the structure, 250.50.

If he currently has a rod or ufer for grounding electrode then the water would only have to be bonded and not use as an electrode. I rarely see a water pipe remain code compliant for use as an electrode.

Thanks George for your insights I certainly can use the help

 

[George Stolz]

If he currently has a rod or ufer for grounding electrode then the water would only have to be bonded and not use as an electrode.

I'm sorry, I must disagree. 250.50 is very clear, all electrodes present at installation must be used.

I rarely see a water pipe remain code compliant for use as an electrode.

Interesting choice of words - you mean after final inspection? Years later?

If this is the context you mean, then that's why the water pipe is to be supplemented as required in 250.53(C)(2).

Thanks George for your insights I certainly can use the help

And I thank you for your good cheer, it's appreciated on my end.

 

[sparks77]

Thanks!

Thanks!

Update:

Thanks guys,

I just wanted to thank everyone for the replies. It gave me some confidence to respectfully and calmly talk to Steve at lunch the next day. Armed with sticky notes and my NEC we met somewhere in the middle. He surprised me and agreed that we needed to make those changes. Then thanked me for discussing it just between the two of us. We removed the "illegal bonding screw", swapped out the old run of SEU with the proper SER (good times in the crawlspace LOL), and had another journeyman check out our grounding/bonding setup....we passed inspection no prob...

Again, thanks!!

Cheers!

 

[tryinghard]

I'm sorry, I must disagree. 250.50 is very clear, all electrodes present at installation must be used.

How so, 250-50: ?If available on the premises?where none of these electrodes are available, one or more of the electrodes specified in 250-52(A)(4) through (A)(7) shall be installed and used.?
In other words one of the items listed in (4) through (7) shall be used.

Interesting choice of words - you mean after final inspection? Years later?

No I mean new construction currently and before inspections, the criteria for the water pipe to be an electrode is not provided, 10? of metal underground water pipe is never installed.

If the water pipe is not an electrode then it still has to be bonded as per 250-104(A)

Dredging ahead & thanks for your input!

 

[George Stolz]

Maybe we're talking about two different things; what I am saying is that I have a building with nothing but copper plumbing from the street 20' away, all the way to the sink.

In that case, there is an electrode as defined in 250.52(A)(1), and it must be used. It must be used whether there's a Ufer, a ground rod, ring, or a 55' Buick buried up to the trunk in the backyard.

I think you're probably saying there is plastic from the street into the house, and copper after that. In that case, the copper inside the house is not an electrode, the plastic outside is not an electrode, and the copper inside the house must be bonded to some degree by 250.104(A).

Is that what we're saying, or do you disagree with some portion of that?

 

[tryinghard]

...what I am saying is that I have a building with nothing but copper plumbing from the street 20' away, all the way to the sink.

I think you're probably saying there is plastic from the street into the house, and copper after that. In that case, the copper inside the house is not an electrode, the plastic outside is not an electrode, and the copper inside the house must be bonded to some degree by 250.104(A).

Is that what we're saying...?

Yep; that's what I've been saying. This is the most common applicaiton that I have seen in my 27 years installing.

 

[George Stolz]

Yep; that's what I've been saying.

I hate arguing with someone who's on the same page as me.

'Round here, I still see mostly copper going in for the water service.

 

[tryinghard]

When the electrode is for the service I personally think it?s best to use a ufer because I believe it actually has the lowest impedance of all. I just think it?s strange to use the water as the electrode because another tradesman not knowing its purpose can destroy it. In summary the purpose for the service electrode is: to drain over-voltages like lightning? (250-4(A)(1)) it cannot use the earth for an effective ground-fault current path 250-4(A)(5) & (B)(4).
The bonding is intended to be the effective ground-fault path - lowest impedance path - to source for a ground fault 250-4(A)(3) & (4). Therefore any ground faults to correctly bonded items will go to the source quickly and open the circuit. In fact the only time a water pipe has to be bonded within 5? of its entrance to a building is when it is used as an electrode, when simply bonded the connection must only be accessible 250-104(A), this is often another place for confusion.

I really appreciate your input!

 

[tonyou812]

sparks i really dont mean to sound rude but i think when you post you should always keep in mind tmi. TO MUCH INFORMATION. keeping it short and sweet is always good.