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rtirwin
ground rods

on the 1/19/2012 episode the electrician placed the ground rods six feet apart in a series connection a parallel connection would be better

jled96
Re: ground rods

They were trying to icrease the disbursement of the ground path, if connected in paralell the distance is only the effective lenghth of both rods, series would double the length, if the ground rods in series were 12' and say 4 feet apart then the effective ground path would be 12x2 pluss the 4' connection giving a 28' effective length, which is plenty adaquate under new codes.

Brad
Re: ground rods
rtirwin wrote:

on the 1/19/2012 episode the electrician placed the ground rods six feet apart in a series connection a parallel connection would be better

According to what or whom?

rtirwin
Re: ground rods
brrichter wrote:

According to what or whom?

electricity always takes the path of least resistance if a power surge hits ground rods in series the first rod will take the bulk of the hit if rods are parallel ( rods 6' apart with #2 copper connecting them and #4 copper going from meter base to the center of the #2 copper connecting the rods ) the surge will be dissipated evenly between the two rods provided the ground resistance is equal at both rods

jled96
Re: ground rods

Both ways would work, but which is better depends on the situation, and the interpretation of the code gets complicated at times, I always present local inspector with the options and let him choose which way he wants ground, most times it is 12'x1/2" solid copper driven vertically in the earth, at the meter base, now I have run into inspectors who want 2 or 3 rods at least 4' apart. I have done quite a few direct burial of rods and always run them in an "s" pattern. In new modern homes there is little to ground to, I have connected to foundation grounds if they had them or to copper water water line, plus at least 1 enternal ground rod, when I started as an apprentice code was #10 copper to the water line thats all, most homes now have pvc/pex plumbing and gas mains which are not conductive. So each situation is different, if your doing a panel swap some inspectors want everything up to 2012 nec, some do not because it has adaquate ground already. Good Luck !

keith3267
Re: ground rods

It is a parallel connection. If it was a series connection, the the wire between the ground rods would have to be tied to the bottom of one of the rods. You are confusing multi point (aka daisy chain) vs home run with series parallel. The electrician daisy chained the ground rods instead of running a separate wire from the meter base to each ground rod.

If the same gauge wire were used for a home run, then there would be the advantage of an effectively larger conductor, but if it were dome in a home run configuration, I would expect that the electrician would use smaller gauge wire to save money. It would just have to meet the current carrying capacity required by the codes.

rtirwin
Re: ground rods

someone needs to read the ( lineman and cablemans handbook ) by Kurts

JLMCDANIEL
Re: ground rods

Reading books is nice but understanding what you read is also important. If you have multiple ground rods with a wire running from the top of one to the top of the next, it does not matter where you connect the wire from the panel. You can connect anywhere along the top to top run and the rods are in parallel not in series. Basic electricity.

Jack

jled96
Re: ground rods

If you are talking utility connections, and power grid applications, as you have referenced a linesman's manual, that is a whole different animal. It is similar , but things are done differently. NEC states:250.56 Resistance of Rod, Pipe, and Plate Electrodes. A
single electrode consisting of a rod, pipe, or plate that does
not have a resistance to ground of 25 ohms or less shall be
augmented by one additional electrode of any of the types
specified by 250.52(A)(4) through (A)(8). Where multiple
rod, pipe, or plate electrodes are installed to meet the requirements
of this section, they shall not be less than 1.8 m
(6 ft) apart.
Informational Note: The paralleling efficiency of rods
longer than 2.5 m (8 ft) is improved by spacing greater than
1.8 m (6 ft). And yes as long as they are connected togeter at some point the discharge will be absorbed into the earth, I better change my rod spacing as new code has them at 6' apart. Good Luck!

rtirwin
Re: ground rods
JLMCDANIEL wrote:

Reading books is nice but understanding what you read is also important. If you have multiple ground rods with a wire running from the top of one to the top of the next, it does not matter where you connect the wire from the panel. You can connect anywhere along the top to top run and the rods are in parallel not in series. Basic electricity.

Jack

you need to do your home work

keith3267
Re: ground rods

I did my homework, and it is still a parallel connection.

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