Why is SER ground so large

[hillbilly1]

Why is there electrical run to the sales racks? You talking in like the lighting section? If they are running pipe down to the shelving from the ceiling and there are pallets stored up there, seems like the problem is a horrible choice of size and/or type of raceway, not with whether or not it has a wire EGC in it.

Never heard of this union = no EGC thing. In any case, I find it unlikely that the electrical contractor of a home Depot is making the decision of using a wire EGC or not, I bet that's already been decided by the engineer who drew up the plans. I've never done a home depot, but I doubt they are "design/build".

It’s probably done by the contractor to offset the higher labor costs by a little. Haven’t seen anything built in the past 20 years that a wire egc is not pulled. But may be different in certain areas in the country.

 

[electrofelon]

It’s probably done by the contractor to offset the higher labor costs by a little. Haven’t seen anything built in the past 20 years that a wire egc is not pulled. But may be different in certain areas in the country.

. I would think if there are egc's specd on the plans the contractor is obligated to follow it.

Yeah it seems to be in the early 90's that everyone started becoming obsessed with grounding and wire EGC's, despite no history of problems. I am design build and rarely use wire egcs. Faults clear just fine.

 

[hillbilly1]

. I would think if there are egc's specd on the plans the contractor is obligated to follow it.

Yeah it seems to be in the early 90's that everyone started becoming obsessed with grounding and wire EGC's, despite no history of problems. I am design build and rarely use wire egcs. Faults clear just fine.

Lawyer’s is probably what happened. If a lawyer can convince a jury that an accident happened because the contractor “Cut corners “ (the lawyers words, not mine) insurance companies would start requiring changes to protect them, regardless if it makes sense, or if there was an actual problem. Everybody has to cya now.

 

[electrofelon]

Lawyer’s is probably what happened. If a lawyer can convince a jury that an accident happened because the contractor “Cut corners “ (the lawyers words, not mine) insurance companies would start requiring changes to protect them, regardless if it makes sense, or if there was an actual problem. Everybody has to cya now.

I doubt that has anything to do with it.

 

[EeeeVeee]

Pic of an add a lug.

Instead of using those, I have typically just used a 1/4-20 bolt to attach a small chair lug to the back of the panel in order to add a new EGC when it won’t fit in the existing ground bar or there are no spaces. Compliant?

 

[LarryFine]

Compliant?

Compliant, with caveats.

 

[EeeeVeee]

Compliant, with caveats.

Such as?

The only one I could think of is removing the paint from the panel under the lug.

 

[LarryFine]

Such as?

The only one I could think of is removing the paint from the panel under the lug.

Machine screw, not wood screw, engaged at least two full threads (or a nut).

 

[EeeeVeee]

Machine screw, not wood screw, engaged at least two full threads (or a nut).

“1/4-20 bolt”

 

[Tulsa Electrician]

“1/4-20 bolt”

Since were talking about a listed piece of equipment. In this case a panle. The bolt and nut may violate the listing. I would think you would need to use a mfg approved method.
I would not use a bolt and nut for the a feeder cable EGC then all others on a EGC buss.
If a bolt nut method was used for equipment grounding I would want to make sure a good connection is established .
NEC
250.4 (A) (5)
250.12
250.148 ( metal boxes (C))

Edit.
I would like to add there is many times we use a bolt and nut for bolting lugs to ground busses etc.

 

[EeeeVeee]

Since were talking about a listed piece of equipment. In this case a panle. The bolt and nut may violate the listing. I would think you would need to use a mfg approved method.
I would not use a bolt and nut for the a feeder cable EGC then all others on a EGC buss.
If a bolt nut method was used for equipment grounding I would want to make sure a good connection is established .
NEC
250.4 (A) (5)
250.12
250.148 ( metal boxes (C))

Edit.
I would like to add there is many times we use a bolt and nut for bolting lugs to ground busses etc.

See this is the thing I don’t understand. If you say that bolting a lug to a panel is a listing issue, then why isn’t it also a listing issue drilling a giant hole in the side of the panel for a 3 inch EMT connector made by a different manufacturer that wasn’t approved for this panel?

 

[Tulsa Electrician]

See this is the thing I don’t understand. If you say that bolting a lug to a panel is a listing issue, then why isn’t it also a listing issue drilling a giant hole in the side of the panel for a 3 inch EMT connector made by a different manufacturer that wasn’t approved for this panel?

I would think this is two different in items.
480.40 grounding of panle boards.

 

[EeeeVeee]

I would think this is two different in items.
480.40 grounding of panle boards.

What part of what I proposed wouldn’t be code compliant?

 

[electrofelon]

Since were talking about a listed piece of equipment. In this case a panle. The bolt and nut may violate the listing. .

There's no such thing as "violating a listing". We are required to follow manufacturer's instructions, but I would challenge you to find any instructions saying not to use a bolt and a nut to mount a lug.

 

[kwired]

I think this is what the UL standard is trying to adhere too. I never really think of bare shield wire as the neutral anymore. That was the old days before my time. And I'm 57. In my eyes, I see bare copper as a ground only. So in short, its not a NEC thing. Its UL directive.

It is "service entrance cable". Grounded service conductor can be bare, and usually needs to be larger than an EGC typically would be with same sized ungrounded conductors.

Just so happens SER type is used for feeder/branch circuit more often than for service entrance, which is permitted.

SEU used to be used quite often for branch circuits to ranges back when we could bond the frame of the appliance to the grounded conductor.

 

[letgomywago]

Since were talking about a listed piece of equipment. In this case a panle. The bolt and nut may violate the listing. I would think you would need to use a mfg approved method.
I would not use a bolt and nut for the a feeder cable EGC then all others on a EGC buss.
If a bolt nut method was used for equipment grounding I would want to make sure a good connection is established .
NEC
250.4 (A) (5)
250.12
250.148 ( metal boxes (C))

Edit.
I would like to add there is many times we use a bolt and nut for bolting lugs to ground busses etc.

The panelboard is the guts the metal can is not and has a construction specification

 

[sparkie1]

This is such a strange conversation. EMT is a fantastic ground, but we all know that fittings and lock nuts can absolutely come loose over time. It happens. So you pull an additional EGC to bond everything. Would I use EMT as an EGC through nipples and such? Most likely. Would I use it on a 50' run of EMT as the sole EGC? Most certainly not.

 

[electrofelon]

This is such a strange conversation. EMT is a fantastic ground, but we all know that fittings and lock nuts can absolutely come loose over time. It happens. So you pull an additional EGC to bond everything. Would I use EMT as an EGC through nipples and such? Most likely. Would I use it on a 50' run of EMT as the sole EGC? Most certainly not.

I fail to see how fittings and lock nuts come loose over time. So this happens to EMT fittings but not wire nuts, ground lugs and ground screws? Very fascinating.

 

[ActionDave]

This is such a strange conversation. EMT is a fantastic ground, but we all know that fittings and lock nuts can absolutely come loose over time. It happens. So you pull an additional EGC to bond everything. Would I use EMT as an EGC through nipples and such? Most likely. Would I use it on a 50' run of EMT as the sole EGC? Most certainly not.

Loose connection on a lock ring on a nipple or a 50' run of EMT and you have a compromised EGC. The thing is when it comes to the 50' or 500' or 2500' run you have a metal conduit tied to metal structure with metal straps, so there is quite a bit of redundancy built in to the long run and a loose coupling or connector won't really be a problem. Not so likely with a short nipple. If you are going to surrender your life to the Cult of the Green Wire there is no half measure.

 

[EeeeVeee]

The way I see it, if someone is so concerned about this that they would pull an extra conductor, then they are the same type of person who would be concerned with installing the raceway properly. So there will be no issue.

All of the raceways that you have seen come apart are due to improper installation or gross physical abuse afterwards.