Adding new ground rod

Users who are viewing this thread

Smith333

Member
Messages
136
Reaction score
4
Points
18
Location
Wisconsin
The cable TV (broadband) and antenna lightning supressor are grounded on the copper water line of my house. The problem is that we installed a water softener with plastic connections, so the grounding no longer exists. On top of that, the grounding points are on the opposite side of the house as the softener and well service entry point.

I think I have two options. I could drive a new grounding rod through the basement concrete floor and into the subsoil. Or, I could run about 100 ft of conductor (not sure which AWG) all the way to the service entrance and ground there. Which is the better idea?
 

Mikey

Aspiring Old Fart, EE, computer & networking geek
Messages
3,024
Reaction score
17
Points
38
Location
Hansville, Washington
Generally, you want the ground path as short and straight as possible. That's a vote for the hole in the floor, but unless the basement ceiling is well over 10' it'll be tough to drive standard rod(s).

I'm a little confused about the water softener installation. If it was just inserted into an existing copper system, it should have been jumpered with a bonding connection from one side to the other to maintain the circuit.
 

Billy_Bob

In the Trades
Messages
419
Reaction score
0
Points
0

Chris75

Electrician
Messages
607
Reaction score
0
Points
0
Location
Litchfield, CT
The cable TV (broadband) and antenna lightning supressor are grounded on the copper water line of my house. The problem is that we installed a water softener with plastic connections, so the grounding no longer exists. On top of that, the grounding points are on the opposite side of the house as the softener and well service entry point.

I think I have two options. I could drive a new grounding rod through the basement concrete floor and into the subsoil. Or, I could run about 100 ft of conductor (not sure which AWG) all the way to the service entrance and ground there. Which is the better idea?



First off, the catv must be bonded within 5' of the water entrance, so must the service disconnect if using the metal underground water pipe as an grounding electrode. with that said, I would just install a jumper around the water softner which you should have done anyways if you read the directions that came with the unit...

If you insist on installing a ground rod you MUST bond that ground rod with the power grounding electrode with #6 AWG copper.
 
Last edited:

Chris75

Electrician
Messages
607
Reaction score
0
Points
0
Location
Litchfield, CT
There is a thing called a "ground loop"...

Therefore it is best to have a "central point of ground" and everything is grounded to this point.

A ground loop is the least of worries when it comes to bonding the grounding electrodes together...
 

Bob NH

In the Trades
Messages
3,310
Reaction score
9
Points
0
Location
New Hampshire
Definitions:
Grounding Electrode - The metal device such as ground rod, or metal water service line, or other conductor in the earth that meets the code requirements.

Grounding Electrode Connductor - The conductor that ties the ungrounded conductor (the neutral) to the Grounding Electrode.

Service - The main disconnect point where the main power enters the house

If the Grounding Electrode is a metal water pipe serving the house then the Grounding Electrode Conductor from the Service must be connected to the Grounding Electrode (the metal water pipe) within 5 ft of where the metal water line enters the house.

The size of the Grounding Electrode Conductor depends on the size of the main breaker but need not be larger than 6 AWG if the Grounding Electrode is a ground rod.

I am traveling and don't have my code with me but I recall that there is a mximum distance from the service entrance to a ground rod that is to be used as a Grounding Electrode.

The ground of the CATV should be connected to the Grounding Electrode System or Grounding Electrode Conductor. The cable wires usually enter the house near where the power enters the house and the ground is usally attached near the Service panel. Can't cite; no code available.
 

Chris75

Electrician
Messages
607
Reaction score
0
Points
0
Location
Litchfield, CT
I am traveling and don't have my code with me but I recall that there is a maximum distance from the service entrance to a ground rod that is to be used as a Grounding Electrode.

No maximum distance, but one would think shorter is better.

The ground of the CATV should be connected to the Grounding Electrode System or Grounding Electrode Conductor. The cable wires usually enter the house near where the power enters the house and the ground is usually attached near the Service panel. Can't cite; no code available.

Not always, but usually. At my house the electric is on the opposite side of the house from the catv drop.
 

Bill Arden

Computer Programmer
Messages
584
Reaction score
0
Points
0
Location
MN, USA
Website
www.billarden.com
The more the merrier.

But... the ground rod needs to be in conductive soil and there is no guarantee that the ground below the slab is conductive enough.

I would suggest adding a ground just outside near where the CATV enters and run a short wire in.

That ground then has to be connected to the main ground rod with heavy enough wire so that it does not overheat during a lighting event.

I don't know what code requires, but I'm guessing 12ga would be good enough.

The only problem with multiple ground rods is keeping the wires between them heavy enough to handle any currents that might occur.

Adding more ground rods will also reduce "ground rise" during a lighting event and thus reduce the voltages that get past the protector.

So... The more the merrier.
 

Bill Arden

Computer Programmer
Messages
584
Reaction score
0
Points
0
Location
MN, USA
Website
www.billarden.com
All the CATV grounding fittings I've seen have holes sized for #8.

The wire between ground rods has to be heavier than the one going to a specific surge protector or grounding fitting.

I am going to guess the #6 AWG requirement comes from the service current rating so that either ground rod wire could handle the fault current caused by a lost neutral wire.
 

pudge565

New Member
Messages
23
Reaction score
0
Points
0
Definitions:
Grounding Electrode Connductor - The conductor that ties the ungrounded conductor (the neutral) to the Grounding Electrode.

Can't beleive nobody else saw this the neutral is the grounded conductor the hot is the ungrounded.
 

Chris75

Electrician
Messages
607
Reaction score
0
Points
0
Location
Litchfield, CT
I am going to guess the #6 AWG requirement comes from the service current rating so that either ground rod wire could handle the fault current caused by a lost neutral wire.


I'm not sure I understand your statement? grounding the electrical system is for limiting voltage imposed by lightning, line surges or unintentional contact with higher voltage lines... thats it...
 

Chris75

Electrician
Messages
607
Reaction score
0
Points
0
Location
Litchfield, CT
All the CATV grounding fittings I've seen have holes sized for #8.

Thats because all you need is #14 to ground the CATV wire, the #6 is for bonding two electrodes together if you happen to drive a rod for the CATV system...

Clear as mud?
 

Mikey

Aspiring Old Fart, EE, computer & networking geek
Messages
3,024
Reaction score
17
Points
38
Location
Hansville, Washington
Clear as mud?
About that :D. I was just musing over the voltage drop in a 10' run of 6AWG copper during an average lightning stroke of 40,000 - 300,000A... Of course, some claim the real purpose of a lightning arrestor is not to carry the full impact of a lightning stroke, but to gradually bleed off potential so that the stroke never occurs.
 

Chris75

Electrician
Messages
607
Reaction score
0
Points
0
Location
Litchfield, CT
About that :D. I was just musing over the voltage drop in a 10' run of 6AWG copper during an average lightning stroke of 40,000 - 300,000A... Of course, some claim the real purpose of a lightning arrestor is not to carry the full impact of a lightning stroke, but to gradually bleed off potential so that the stroke never occurs.

What do you mean by lighting arrestor? The device you can buy, or a ground rod?

The reason we only need #6 to a ground rod is because thats all the earth is good for anyways... any wire bigger than that would be useless.
 

Mikey

Aspiring Old Fart, EE, computer & networking geek
Messages
3,024
Reaction score
17
Points
38
Location
Hansville, Washington
We must have especially good dirt here in Lightning Alley... my house came with a lightning rod system and the downleads are about 5/8" stranded aluminum.

"Lightning arrestor" was a poor choice of terms. "Lightning protection system" is better, but still bogus, I think.
 

Bob NH

In the Trades
Messages
3,310
Reaction score
9
Points
0
Location
New Hampshire
I goofed on the grounded vs ungrounded conductor. The Neutral is the GROUNDED couductor. Brain wasn't working on that one.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks