Grounding? Bonding

old-9

Well-known Member
The post below is getting Full and confusing, I was an electrician(?) for 40 years and have been retired almost 8 years. I burned my code books and tryed to forget most of this stuff. As I rember it the NEC has 2 terms -ground(ing) and bonded/ bonding. You ground the service and bond the devices. That said some things are bonded to the system other things (structures) are grounded. I have worked at many places over the years and did a LOT of grounding. At a steel mill every column had a ground "nest" consisting of 3 thirty foot ground rods spaced ten feet apart connected with a loop of 500MCM bare copper wire and run to a grounding plate on the column. This cable was "cadwelded" to each rod and no mechancal splices were allowed.. At a school of steel frame construction, at all corners we also put down a triple nest of ground rods this time 4/0 wire and also cadwelded joints.
To take the cake I worked in a nuclear powerhouse, everything was "bonded" with 4/0 solid copper wire all cadwelded. I worked on the lighting in one area and instead of insulated neutral wire we had to use #12 solid bare wire, all joints were twisted, soldiered and wirenuts. All this in EMT conduit.
I never worked on any farms in my career but I would guess all grain bins, permanent grain dryers, elevators, basecally all metal structures should be grounded with ground rods. Ths would be for lighting protection. Grain dust, as all of you know is very explosive, so static sparks are not good.

Now all electrical equipment is bonded /grounded to the panel which is also "bonded" to the bulding if metal constructed. It seems like we were to bond the metal sidding on like a pole bulding. (not to sure on that). I mostly worked on industral steel framed buldings. Now if you want to go into " explosion proof" or ???? you are going to have to start another thread. Just leave you with this thought "do you have a 120 volt pump on your fuel tank"? and is it wired right?

joe
cadweld
 

According to 2 practicing electricians I asked. Grounding a panel in an outbuilding fed from the main premise panel is done thru the wire feeding the sub-panel for 220 it would be 3 wire with ground and the neutral and ground only being bonded/connected back at the main panel. No earth grounding is required at the outbuilding.
 
(quoted from post at 23:00:35 11/15/14)
According to 2 practicing electricians I asked. Grounding a panel in an outbuilding fed from the main premise panel is done thru the wire feeding the sub-panel for 220 it would be 3 wire with ground and the neutral and ground only being bonded/connected back at the main panel. No earth grounding is required at the outbuilding.
Required"? By whom? Out in the boonies, nothing is "required", do whatever will light a bulb. Now, if we are talking NEC compliant, those two need to do more than twist wires & study the NEC book, maybe take a course on understanding the NEC.
 
old 9 VERY GOOD POST, thank you. Hope we dont bore the non electricians or non engineers or non technicians here, but hey were having fun and maybe can help a person or educate them or prevent a tragedy AND THATS NEVER A WASTE IN MY OPINION. Besides they have the right and choice to not read all this sparky jibber!!!


1) INDEED the terms Grounding versus Bonding are often misused and I've certainly been guilty myself. If you stroll over to Mike Holts website he has entire articles and videos on Grounding versus Bonding.

2) AS far as what are "Grounding Electrodes" and which to use, when and where I practiced the NEC required WE BOND TO ALL READILY AVAILABLE ELECTRODES. Such electrodes consisted of continuous metal water or gas pipes,,,Building structural steel,,buried electrodes and buried structural steel,,and if NONE existed we could use a MADE ELECTRODE such as 1 or 2 driven into the earth rods. NO the siding on a pole building WAS NOT A GROUNDING ELECTRODE as I recall.

3) In my jurisdiction and in every place I observed or practiced any buildings (home, farm. shop, separate garage, pole building) electrical service entrance was connected to a Grounding Electrode. It remains my professional opinion, based on an electrical engineering education and years of experience including NEC Seminars (taught by experts and even those on NEC panel), that any buildings electrical service is to be connected to a Grounding Electrode and so far no one (especially any trained professionals) has submitted any real, hard, technical evidence and proof and an exact applicable citation that the NEC does NOT require that. If so I'm willing to learn so am interested if and why and when a service should NOT be connected to a grounding electrode. Like all I've been wrong before but prefer to err on the side of safety if in doubt in the meantime. If connection to a grounding electrode is NOT required I have an open curious mind and would love to learn why not.

SOME THINGS I LEARNED AND OBSERVED OVER YEARS AS AN ELECTRICAL DISTRIBUTION AND DESIGN ENGINEERING (and it holds true here for the most part) is that trained professional experienced electricians and engineers and technicians ADHERED TO AND PRACTICED IN ACCORDANCE WITH THE NATIONAL ELECTRICAL CODE REGARDLESS IF IT HAD BEEN ADOPTED OR NOT IN THE JURISDICTION. It was their Bible regardless if any authority adopted it or not, that (adoption or not) wasnt the issue

Yet many non professional non trained lay persons often ignored it or poked fun or argued against it as if they knew better !!!!!!!!!!! That might tell you something!!!!!!!

MOST IMPORTANT as indicated here and Ive observed all my profession life, INSPECTORS OR ELECTRICIANS CAN GET IT WRONG they are only human and obviously not as sharp on electricity as the complete NEC panel and board (that's NOT just one person mind you, but a team of true experts) and just because they (inspectors or electricians) do something one way that DOES NOT MEAN its NEC proper WELL DUH LOL.

HOWEVER as pointed out below and with which I agree and cant argue IF A LOCAL INSPECTOR SAYS ONE THING (even if contrary to NEC) THE REALITY IS YOURE STUCK WITH IT because he's in charge and you wont get your service turned on otherwise so HE RULES right or wrong. THATS THE HARSH REALITY even where the inspector is wrong

So God Bless all who contributed and helped and asked questions and I hope people learned something and will keep safe AND WERENT TOO BORED LOL

John T Long retired EE so as always NO WARRANTY Im rusty on latest codes and may be right or may be wrong (have often been before lol) but in my head and heart try my best to help and prevent a tragedy and want all to be as safe as possible SO DONT GO OUT AND RIP OUT ANY GROUND RODS just because some inspector in some location is of the opinion (may be wrong may be right) they are NOT required.
 
I forgot your final question:

"do you have a 120 volt pump on your fuel tank"? and is it wired right?"

WOW not talk about AN IMPORTANT SERIOUS AND CRITICAL WIRING ISSUE.

I have NOT studied the NEC concerning your question BUT IF THERE EVER WAS A TIME WHEN YOU SHOULD FOLLOW THE NEC AND NOT BILLY BOBS OR ANY LAY PERSONS ADVICE THIS IS IT !!!!!!!!!!!! CONSULT A TRAIEND EXPERIENCED COMPETENT PROFESSIONAL if in doubt.

For sure, the third wire safety equipment GroundING Conductor comes to mind in this application. Talk about a place where you want a dedicated low impedance fault current return path!!!

Im not taking the time to research and offer advice as the what the NEC has to say about it, only that do it right or you may die !

Good question old 9, I don't have the answer but if I were to wire one you can bet I would consult the NEC and no way rely on untrained non professional or Billy Bobs advice.

John T
 
(quoted from post at 23:00:35 11/15/14)
According to 2 practicing electricians I asked. Grounding a panel in an outbuilding fed from the main premise panel is done thru the wire feeding the sub-panel for 220 it would be 3 wire with ground and the neutral and ground only being bonded/connected back at the main panel. No earth grounding is required at the outbuilding.

So why would you want to? Do you not want to foot the $10,000 bill and wait the four weeks to drive a couple of ground rods ? If the equipment doesn't immediately explode into a sparking ball of flame then the wiring is fine? maybe you ought to speak with to the Fire Marshal and insurance company inspectors.
Is the problem that it's not your idea and it's somebody else's ?
 
Glen, okay as the Equipment Grounding Conductor is ran in parallel with the hot ungrounded phase conductor over a long distance due to capacitance and inductance, by the time it gets out to the sub panel

DO YOU THINK ITS VOLTAGE POTENTION WITH RESPECT TO MOTHER EARTH MIGHT POSSIBLY END UP HIGHER THEN THAT BACK AT THE MAIN WHERE THE GROUND ROD WAS INSTALLED???????????

I bet when old bossys nose (or you barefoot grandchild) touches a water tank or auto water or a tool or appliance etc that has the required equipment grounding conductor attached THEY WILL FEEL A SHOCK.

DARN NEC requires (in my professional opinion, but I may be wrong, Im waiting for a cite that says different) a Ground Rod out at the remote shop or pole barn or garage and that would bring the ground wires potential back down to mother earth there (Plus serve other safety purposes about lightning and surge and other protection) BUT WHAT DO THEY KNOW LOL Billy Bob and Bubba and other non trained non professionals have got by without a ground rod and even some local inspectors may not want one BUT UNFORTUNATE THEY RULE AND IT DONT MATTER IF THEY ARE NOT NEC COMPLIANT OTHERWISE YOU DONT GET THE ELECTRICITY TURNED Sighhhhhhh

Keep safe yall

Thanks for all your help and expertise Glen

John T
 
If you ever have a cadweld blowout instead of cutting the wires shorter and doing it all over fill the mold with solder flux squeeze the mold back over the blown splice then recharge the mold . The second time with the flux it will fill all the voids in the first bad mold. If you use good molds you don't need duct seal. Don't ever try to use a Bic lighter or you will have an instant blister formed on your thumb from the heat. Not all the charge powder is the same the fine powder on the bottom of the charge is the ignitor powder and must lay on top. It is true welding with a sparker and no torches at all.
 
I had the training, at the powerhouse you had to have a license to cadweld, still have a pistol sparker , but I liked to use a propane torch to set them off. And don't open the mold too soon!
One of the coldest winters I spent driving 30 foot ground nests. Oh, the good old days! The rods were 10 feet and were coupled together.
joe
 
(quoted from post at 11:31:44 11/16/14) Glen, okay as the Equipment Grounding Conductor is ran in parallel with the hot ungrounded phase conductor over a long distance due to capacitance and inductance, by the time it gets out to the sub panel

DO YOU THINK ITS VOLTAGE POTENTION WITH RESPECT TO MOTHER EARTH MIGHT POSSIBLY END UP HIGHER THEN THAT BACK AT THE MAIN WHERE THE GROUND ROD WAS INSTALLED???????????

I bet when old bossys nose (or you barefoot grandchild) touches a water tank or auto water or a tool or appliance etc that has the required equipment grounding conductor attached THEY WILL FEEL A SHOCK.

DARN NEC requires (in my professional opinion, but I may be wrong, Im waiting for a cite that says different) a Ground Rod out at the remote shop or pole barn or garage and that would bring the ground wires potential back down to mother earth there (Plus serve other safety purposes about lightning and surge and other protection) BUT WHAT DO THEY KNOW LOL Billy Bob and Bubba and other non trained non professionals have got by without a ground rod and even some local inspectors may not want one BUT UNFORTUNATE THEY RULE AND IT DONT MATTER IF THEY ARE NOT NEC COMPLIANT OTHERWISE YOU DONT GET THE ELECTRICITY TURNED Sighhhhhhh

Keep safe yall

Thanks for all your help and expertise Glen



John T

All electrical conductors have VD when current is flowing. The ground wire is no exception. Hence bonding everything metal together and having ground electrodes at every panel is a good idea.
This has long gone past what the laws of physics and into Bubba says "I'll d*mmed well do what I want as long as it's different that what YOU say".
 
(quoted from post at 01:45:12 11/16/14)
(quoted from post at 23:00:35 11/15/14)
According to 2 practicing electricians I asked. Grounding a panel in an outbuilding fed from the main premise panel is done thru the wire feeding the sub-panel for 220 it would be 3 wire with ground and the neutral and ground only being bonded/connected back at the main panel. No earth grounding is required at the outbuilding.
Required"? By whom? Out in the boonies, nothing is "required", do whatever will light a bulb. Now, if we are talking NEC compliant, those two need to do more than twist wires & study the NEC book, maybe take a course on understanding the NEC.

We are talking NEC code. One is an inspector.
 

John T, the ground rod potential at the outbuilding may be different than the potential at the main service entrance ground. Earth ground is not always at the same potential.
 
I agree IH, heck old mother earth isn't the same at two places. I was also thinking about about one possible advantage in bringing the equipment ground buss back down to the same as mother earth OUT THERE AT THAT REMOTE POLE BARN by bonding it to a grounding electrode (ground rod) once the electrical service is out there. That way when old bossy touches the heated electrified waterer that's connected to the Equipment Ground Buss out at that barn, its (if grounded out there to local mother earth potential again) closer to local earth potential then if it were ran out from the house in parallel with the hots and bonded ONLY back at the house and no ground rod at the barn OUCH says old bossy lol

The code has a lot of good advice about grounds at ag buildings used to house livestock that address the issues above and how to keep old bossy shock free,,,,,,,,,

VERY FUN CHATTIN WITH YA, thanks

John T
 
(quoted from post at 21:21:33 11/16/14)
John T, the ground rod potential at the outbuilding may be different than the potential at the main service entrance ground. Earth ground is not always at the same potential.

That would be why we ground each location well and bond everything together. To obtain a ground plain where everything is at as close as practically possible to the same potential.
 

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