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Discussion Starter #1
I have a general question about grounding rods:

If a residential dwelling is located in an urban setting, such that the main panel is at the front of the residence, and that the front of the property is directly joined with the sidewalk and street, and the grounding rods are installed inside the basement, below the panel...

How should a grounding rod be installed if the ceilings inside the basement of the residence have only 6ft of clearance? I understand the requirement is at least 8ft rods, how can I drive them with only 6ft of space?

Thanks greatly
 

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Drive the rods at an angle. The rods could even be buried horizontally, provided they are at least six feet apart. Do you have a concrete floor?
 

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Discussion Starter #3
Drive the rods at an angle. The rods could even be buried horizontally, provided they are at least six feet apart. Do you have a concrete floor?
Yes, full concrete floor. The panel itself does not appear to be grounded to the water service either, but there 'is' a jumper cable across the meter itself, does this mean it is grounded somewhere? Would this allow for only one rod? The panel only has a neutral bus bar with no ground bus bar as well. Multiple neutrals and grounds sharing lugs. I was thinking about adding a ground bus bar, ground rod, bond it to the water service, and then add a sub panel to allow for more space.

Question is how??
 

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Discussion Starter #4
Drive the rods at an angle. The rods could even be buried horizontally, provided they are at least six feet apart. Do you have a concrete floor?
Also, how dangerous would it be to add a subpanel without the presence of the grounding electrode at the main panel? This is in a row home same height as the other 20 row homes in our block so a targeted lighting strike is unlikely, I do want it to be safe however.
 

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Also, how dangerous would it be to add a subpanel without the presence of the grounding electrode at the main panel? This is in a row home same height as the other 20 row homes in our block so a targeted lighting strike is unlikely, I do want it to be safe however.

Id be far more concerned about making sure your incoming water supply is bonded correctly.
 

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Sounds like an older style setup, with grounding at the meter.

In your main panel, your neutrals and grounds can share a bar, but not typically the same screw. Any new ground bar would have to be bonded to neutral.

Before you drive a rod, make sure there are no utilities under your house in the area you want to drive the rod. If you're all clear, I'd get a heavy hammer drill with a 3/4 inch or 1 inch bit, hammer strait down for about a half inch and then go in at an angle steep enough to let you drive your ground rods. There are ground rod driving bits as well that will make hammering the rod in easier.

It might be easier to make your current main into a subpanel, and install a new main panel.
 

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Discussion Starter #7
Id be far more concerned about making sure your incoming water supply is bonded correctly.
The first step would be having a dedicated ground bus bar in the panel correct? Then running I believe #4 ground wire to an approved clamp on the street side of the meter? Correct me if I'm wrong
 

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Discussion Starter #8
Sounds like an older style setup, with grounding at the meter.

In your main panel, your neutrals and grounds can share a bar, but not typically the same screw. Any new ground bar would have to be bonded to neutral.

Before you drive a rod, make sure there are no utilities under your house in the area you want to drive the rod. If you're all clear, I'd get a heavy hammer drill with a 3/4 inch or 1 inch bit, hammer strait down for about a half inch and then go in at an angle steep enough to let you drive your ground rods. There are ground rod driving bits as well that will make hammering the rod in easier.

It might be easier to make your current main into a subpanel, and install a new main panel.
By 'heavy hammer drill' what are we talking here? I own a hammer drill but I'm unsure if it can handle that size bit. How do the driving bits work?

Also, due to the cost of installing a new panel/new feed wires etc. I feel like it would be easier to just install a new sub to allow for expansion. Are there known complications with that? Also, how do I bond a new ground bar to the current neutral bar?
 

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Discussion Starter #10
Something like this:

http://www6.homedepot.com/tool-truck-rental/Roto_Hammer_1/HR2811F/index.html

The driving bit would plug into the same hammer drill and hammer the rod in.

You might have issues with clearance around your panels in the basement, given the short ceiling, at least on new work. I'll defer to someone else on that, though.
By clearance you mean for hammering the rods in? If that's not possible for me to do myself right now would it be at least acceptable to bond the system to the water system? Wouldn't that act as the same thing? I know it wouldn't be up to code but as long as it's safe for right now and would allow me to add a sub panel
 

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does the water system have metal pipes that go into the ground ?
So that you would get a reasonable ground connection from them ?
:glasses:
 

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Discussion Starter #12
Yes, the pipes are copper and extend under ground under our porch and sidewalk out the the main shut off at the street maybe 10 ft from meter.

Once bonding is done what type of sub panel would be ok with the 100amp service? The main panel is a 100 amp square d with I believe 12 spaces
 

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If you want to get maximum protection from the ground rods (for what thats worth) the rods are more effective if placed twice the distance of the length, 8' rods 16' feet apart.
 

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The first step would be having a dedicated ground bus bar in the panel correct? Then running I believe #4 ground wire to an approved clamp on the street side of the meter? Correct me if I'm wrong

Yes, for a 200amp service. But a separate ground bar is not required in the main panel. On a 100amp service #8 cu will do.
 

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Discussion Starter #15
Yes, for a 200amp service. But a separate ground bar is not required in the main panel. On a 100amp service #8 cu will do.
Ok so what I want to do is add a 100 amp sub panel off of the main 100 amp panel. The main panel is a Square D 100 amp Series E7 Panel. I am trying to locate the maximum size breaker (for subpanel) it can accommodate without it being an issue. I know 100 amps is the maximum rating but don't panels have limits for each breaker installed?

I do plan to upgrade to 200 amp in the future but right now this is all I can afford. So I will do a run of #4 copper so I don't have to upgrade that too in the future. Just because its heavier doesn't mean it's wrong does it?
 

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Discussion Starter #16
If you want to get maximum protection from the ground rods (for what thats worth) the rods are more effective if placed twice the distance of the length, 8' rods 16' feet apart.
Also the problem I'm faced with in the main is that there is no more room to have single neutrals under each screw. Some used to have 3 ground or two neutrals under one screw until I eliminated a circuit. The panel cover says there's room for 24 standard sized breakers max 48 but the actual panel only has room for 12/24. The hot bus bars don't even extend to where the panel cover has knockouts for breakers, it doesn't make any sense to me really.
 

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Ok so what I want to do is add a 100 amp sub panel off of the main 100 amp panel. The main panel is a Square D 100 amp Series E7 Panel. I am trying to locate the maximum size breaker (for subpanel) it can accommodate without it being an issue. I know 100 amps is the maximum rating but don't panels have limits for each breaker installed?

I do plan to upgrade to 200 amp in the future but right now this is all I can afford. So I will do a run of #4 copper so I don't have to upgrade that too in the future. Just because its heavier doesn't mean it's wrong does it?

In that case #4 is fine and will have you covered :thumbsup:
 

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Discussion Starter #18
In that case #4 is fine and will have you covered :thumbsup:
Thanks a bunch! How exactly do I connect this to the panel? Does it get bonded to the neutral/ground bar or is bonding to the panel case sufficient? How do I go about that? Also how do I figure out how to wire up a sub panel to this 1970's panel?
 
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