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Old 12-10-2012, 12:51 PM   #1
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Proper Grounding


I have an older home that was recently updated with a new 200amp service. The home did not have any ground wires in it before and I am running new wires to get things up to date. I noticed the service is grounded at the meter which is about 50 feet away from the home. My question is this. Do I need to run ground rods near the service entrance to the house and connect to the service ground or is the grounding at the meter sufficient?

This house had a history of lightning surges and there were two different surge protectors added with the new 200 amp panel at the time of the update.

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Old 12-10-2012, 01:15 PM   #2
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You will need two ground rods at the house, connected to the panel with a #6 copper wire as a grounding electrode conductor.

Had the meter been mounted on the side of the house, two ground rods below it would have been sufficient.

(A subpanel in a separate building such as a detached garage would need its own pair of ground rods.)

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Old 12-10-2012, 01:48 PM   #3
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I have an older home that was recently updated with a new 200amp service. The home did not have any ground wires in it before and I am running new wires to get things up to date. I noticed the service is grounded at the meter which is about 50 feet away from the home. My question is this. Do I need to run ground rods near the service entrance to the house and connect to the service ground or is the grounding at the meter sufficient?

This house had a history of lightning surges and there were two different surge protectors added with the new 200 amp panel at the time of the update.
Where is the service disconnect?
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Old 12-10-2012, 06:16 PM   #4
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The service disconnect is at the breaker panel in my attached garage. My phone (internet) service is near the panel also. Do I need to ground to this also?
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Old 12-10-2012, 06:57 PM   #5
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You run the grounding electrode conductor from the ground rods to the panel with the first main disconnect, here, in your garage. Other panels downstream (subpanels) in the same building, even if they are larger, do not need ground rods but must be fed with separate ground (equipment grounding conductor) and neutral from upstream.
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Old 12-10-2012, 07:29 PM   #6
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Thanks for the help everyone.
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Old 12-11-2012, 12:43 AM   #7
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The service disconnect is at the breaker panel in my attached garage. My phone (internet) service is near the panel also. Do I need to ground to this also?
Important earth ground must be close to the service disconnect. That is also where the two 'added' protectors must be located.

Also adjacent should be a telco 'installed for free' protector.

A protector does not do surge protection. A protector only connects to what does protection. That would be an earth ground installed when upgrading the panel. Those two protectors and the telco 'installed for free' protector must make a low impedance (ie 'less than 10 foot') connection to that earth ground. Every foot shorter means better protection. Wire length is that important for protection.

Grounds at each receptacle are different. Those safety grounds are mostly for human safety. Same with each ground for separate panels. Each panel must connect be safety grounded to a bus bar in the main box ... for human safety reasons as detailed by code.

Different grounds serve different functions. Safety grounds inside the house are described by completely different codes. The service entrance earth ground is always installed for human safety. To make those surge protectors effective, that same earth ground must also exceed code requirements.

And finally, an incoming TV cable must also connect short to that same earth ground before entering the building. Best protection (better than using a protector) is a wire from cable to earth. That wire is required by code for human safety. And also does transistor safety (surge protection).
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Old 12-11-2012, 07:47 AM   #8
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While we are on the subject. I noticed this morning the water pipes need bonded to ground also. I have a boiler in the home that feeds the copper hot water baseboards for heat. Can I connect into the ground wire at the water circulation pump to ground the water pipes or do I need to drill through the floor and hammer in a ground rod???

All the potable water, heat pipes and gas pipes all come into the home in the same corner where the boiler is located. This is on the other side of the room (garage) from the breaker panel.
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Old 12-11-2012, 08:47 AM   #9
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(mincing words)
If A is bonded to B then B is bonded to A.
But ... The purpose of putting a bonding jumper between the heating pipes and the electrical panel is to bond the heating pipes to the electrical system ground, not to bond the electrical system ground to the heating pipes.

If the bonding jumper from a section of plumbing first reaches a grounding electrode conductor of at least the same size, then it may end and be clamped on there. It is not necessary to position a new ground rod in the basement floor next to the pipes.

Bonding jumpers are recommended for sections of metal plumbing up in the house isolated by intervening sections of plastic pipe and these bonding jumpers may be clamped to where metal pipe resumes rather than going all the way to the electric panel or a GEC.

(The bonding jumper for plumbing is sized using the same rules as a grounding electrode conductor to a water pipe e.g. #6 copper for electrical service up to 100 amps.)
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Old 12-11-2012, 09:28 AM   #10
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The water pipe coming into the home is plastic then changes to steel which is also interconnected into the boiler for filling the pipes. There are no metal pipes touching the ground in the system. I just ran a new line into the boiler circulation pump and it is now grounded so would this in turn make the plumbing also grounded as it needs to be??? There are no sections of plastic separating metal piping.
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Old 12-11-2012, 12:12 PM   #11
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When the furnace or boiler (uses electricity and) is served by an up to date branch circuit (with equipment grounding conductor) and up to date panel with grounding electrode system (ground rods, etc.), then the plumbing connected to it is considered to be adequately bonded to ground.
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Old 12-13-2012, 08:43 AM   #12
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This is on the other side of the room (garage) from the breaker panel.
You asked about grounding to eliminate surges. That means earth ground must be "single point earth ground". Using two grounds at opposite ends of a building make all appliances a better and destructive path from a cloud to earthborne charges. Some are confusing ground for human safety with ground for surge protection. Critical - as in no alternative - is a single point ground. And the connection must be low impedance. That means as short as possible (ie 'less than 10 feet' to that single point ground), no sharp wire bends, no splices, etc.

Water pipes are not acceptable for grounding. But water pipes must be connected to the grounding system. That applies to grounding for human safety. Transistor safety (surge protection) means earth ground must be even better. Single point ground. Short as possible connection. Ground wire not inside metallic conduit. And other requirements. So that a surge goes to earth without passing anywhere inside the house.

These concept are discussed by numerous sources. One example:
http://lists.contesting.com/_towerta.../msg00760.html
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Old 12-13-2012, 01:37 PM   #13
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It might help to state that there are two terms, grounding and bonding. Grounding systems are intended to clear faults aplied to the electrical system. Bonding is intended to ensure that conductive objects (pipes, steel framing, pool walls and water, patios surrounding pools, etc.) are at the same electrical potential as the grounding system.

The grounding system includes all equipment ground wires and conduit used as an equipment ground, the grounding electrode conductor (the large bare copper wire from the service disconnect ground bus to the electrodes) and the electrodes themselves (driven rod(s), UFER's) and all hardware that connects these components.

The bonding system(s) is/are any wires and hardware such as clamps, connecting items to be bonded with the grounding system.
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Old 12-13-2012, 05:39 PM   #14
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It might help to state that there are two terms, grounding and bonding.
I may have described same using different terms. Two ground systems are described by code in two completely different articles. Because each is so different.

A wall receptacle ground prong, ground wires inside the building, and a ground bus bar in the breaker box are parts of the the safety ground system. Code calls it equipment ground. Some summarize what it does as bonding.

That is completley different from another ground described as earth ground. Ten foot copper clad steel rods, Ufer ground, steel plates, etc are examples. But wall receptacle safety ground is not part of an earth ground. Safety ground connects to a main breaker box bus bar. That ground bus bar makes a separate connection to earth - typically a quarter inch, bare, solid copper wire.

Wall receptacle 'three light' testers can report a safety ground failure. But cannot say anything about the earth ground. Because the two grounds are distinct and electrically different.

Bonding generally refers to connecting electrically conductive items to the safety ground system. Again, mostly to protect human life. Code is all about human safety.

The OP asked about something different. Earthing a surge is about earth ground. Wall receptacle safety grounds are typically many times too distant, have splices and sharp bends, are bundled with other wires (ie 'black' hot and 'white' neutral), may be inside metallic conduit, etc. Each is but another reason why a wall receptacle safety ground does not make a sufficient connection to earth.

Bonding and earthing are different as even described by code. And then other electrical reasons make that difference greater. Makes a wall receptacle safety ground virutally useless for earthing a surge current.
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Old 12-14-2012, 08:44 AM   #15
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Ok so here is the plan...I need to run #4 bare copper wire from the ground buss in the breaker panel directly to two 5/8" ground rods a minimum of 6' apart. Can the wire terminate at the second rod or should it loop back to the breaker panel?

The breaker panel is on an outside wall so the distance to the first ground rod will be around 3'. Can I run the ground wire down from the panel inside the wall next to the insulation then out through the siding just above the foundation or do I need to put this in conduit...plastic or metal?


This morning I also found a green #10 ground wire in the attic and traced it to the other side of the house where it ran down through the soffit and along the trim on the door to two 1/2" ground rods that were buried about 8" apart. It is hooked to the ground buss in a large junction box in the attic where all the old wires and new wires from the service update were joined (the service panel was moved from a side room to the garage when the update was done). All the wires that have grounds that come into this junction box are hooked into the buss with it.

Should I leave this ground hooked up as it is or could this cause a problem??? The wire distance is around 20 feet.

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