Grounding wire (stranded or solid)?

[MONSTERMAN]

Hello,
Since a 10AWG solid copper wire is hard to find and when found it is expensive and hard to work with, will a (stranded) multiple grounding wire work instead? The stranded wire is everywhere and in solid copper, also much cheaper and should be a lot easier to work with. I'm giving up on the 6AWG copper wire, that is just way too big (costly) and hard to work with. I have about 30 feet from the roof to connect to my 8' copper grounding rod.
Thanks

:confused:

[HDTVsportsfan]

I'm pretty sure it has to be solid.

[houskamp]

shouldn't matter.. 10ga is 10ga.. rated by current carrying capacity.. only "nice" thing about solid is it's easier to connect with the screw type connectors on the sat stuff..

[Scott in FL]

Agreed, stranded is fine. And you can leave the insulation on if you wish, it does not need to be bare. Just a couple of things:

Make sure your connections to the antenna and ground rod are nice and solid. Stranded is harder to work with in this regard, so take the time to get it right. I would coat the entire connection with GE Silicon II to protect it from corrosion (that is, once the connection is made, cover it).

Lightning pulses have a relatively low RF frequency, so don't make any sharp bends in the ground wire. A sharp bend will look like an RF choke to a lightning pulse. Use a minimum bending radius of 18" if possible.

By the way, "no sharp bends" is a good rule for RG-6, too. Not for the same reason, and the minimum bending radius can be less than 18", but don't make tight bends around corners where the coax is pulled tight.

[Hansen]

I disagree. To carry the ampeage of a near hit lightening strike, you'll need solid copper; stranded will not handle that load. 10 gauge stranded copper is not the equivilent of 10 gauge solid copper.

[houskamp]

I disagree. To carry the ampeage of a near hit lightening strike, you'll need solid copper; stranded will not handle that load. 10 gauge stranded copper is not the equivilent of 10 gauge solid copper.
If you look most houses are grounded with stranded..
the wire gauge is by the current carrying capacity not the diameter.. doesn't matter if it's stranded or solid, it will fry at the same loads...

[HDTVsportsfan]

If you look most houses are grounded with stranded..
the wire gauge is by the current carrying capacity not the diameter.. doesn't matter if it's stranded or solid, it will fry at the same loads...


That's odd...in my area I see solid. Literally 20 years ago I used to paint houses and was always outside on new construction. I recall seeing mostly solid. Oh well.

[Scott in FL]

I disagree. To carry the ampeage of a near hit lightening strike, you'll need solid copper; stranded will not handle that load. 10 gauge stranded copper is not the equivilent of 10 gauge solid copper.

From www.lightningconsultants.org: Where ever possible when high frequency energy is to be handled it is preferable to use stranded conductor vs. solid conductor. The surface area of a stranded conductor is greater than that of a solid conductor and therefore it is better able to handle high frequency energy.

A lightning pulse is a high frequency transient pulse.

Further, my 60' radio tower has withstood hits and nearby strike induced pulses several times. I use stranded ground wire.

[Mike500]

I disagree. To carry the ampeage of a near hit lightening strike, you'll need solid copper; stranded will not handle that load. 10 gauge stranded copper is not the equivilent of 10 gauge solid copper.

Actually. stranded conductors are better at conducting electricity than a solid conductor. It's called the "HALO EFFECT."

Stranded also is less likely to be destroyed by vibrational fatigue and is preferred for easy of pull through conduits.

[Hansen]

The stranded wire you are referring to (for a radio tower or lightening arrest system for a home) is of much larger size than 10 gauge solid copper. In fact, in those applications each of the strands may be 10, 12, 14, or 16 gauge. In those instances, stranded works better and is more user friendly. But in the size of 10 gauge solid and difussing a near hit charge of lightening you would need something much more substantial than 10 gauge stranded to get the equivalent ampereage carrying capacity for disippation to ground. Truth be told neither will help much beyond the static charge of the near hit. As for a direct hit, say so long to the dish and equoment attached and hope for no fires.

Also, it has been a while since I looked at the NEC but doesn't it specify solid copper for residential service grounds.

[David MacLeod]

be safe, do what local codes require. can't get hurt on insurance if code is met.

[Scott in FL]

Stranded is a better conductor for lightning protection regardless of the wire size. That is, AWG 10 stranded will be a better conductor than 10 AWG solid.

Lightning strike rise times can vary from a very fast 0.25 μS to a
very slow 12 μS, yielding an RF range up to 1 MHz. RF energy travels near the surface of a wire as opposed to within the central core of the wire (skin effect). So for lightning protection, a stranded conductor will exhibit a lower impedance than solid. This equates to a higher current carrying capacity.

AWG 10 (solid or stranded) would not withstand the full current of a direct strike. But direct strikes rarely happen, the entire ground system will "rise up" above ground due to losses, and the duration is very short.

Both the NEC and NFPA specify stranded for lightning protection.

[Incompetent]

If lightning strikes your dish, good luck with anything. A solid bolt of lightning will most likely fry everything if not catch your house on fire.

That ground is there to dissipate static currents that build up around the dish. It also serves to make people feel safer since a dish isnt really much of a lightning rod.

I would say that if you are that worried about it then take out a higher deductible on your homeowners insurance.


Just remember what its actually bonded too. Is it the meter pan or is it the meter ground? The ground wire should run all the way down and bond near the dirt, most likely with a split-bolt.

[Scott in FL]

That ground is there to dissipate static currents that build up around the dish. It also serves to make people feel safer since a dish isnt really much of a lightning rod.

Not true. What usually happens is a nearby strike induces a high voltage spike into the antenna and coax cable runs. This spike can be effectively bypassed to ground with a low impedance ground system.

Low impedance means stranded wire (really, AWG 8 or 6), run as short as possible with no sharp bends, connected to a minimum of one 8' copper coated ground rod driven all the way into the ground.

[Incompetent]

SBCA installes are strictly forbidden from installing grounding rods.

It didnt use to be that way, but according to NEC only a licensed electrician should install a ground rod.

hence the ground wire going all the way down to "dirt"

[RobertE]

ugh, not more grounding/lightning debate AGAIN. :bang :icon_dumm

[TigersFanJJ]

That's odd...in my area I see solid. Literally 20 years ago I used to paint houses and was always outside on new construction. I recall seeing mostly solid. Oh well.

I've seen both but solid is much more common from the meter box to the ground rod. I've never seen anything other than stranded coming from the pole to inside the meter box.

[TigersFanJJ]

ugh, not more grounding/lightning debate AGAIN. :bang :icon_dumm

Well, it is Tuesday. :lol:

[RobertE]

be safe, do what local codes require. can't get hurt on insurance if code is met.

Absolutely correct.

The faceless typings of some unknown person out in cyberspace mean zippo when in comes crunch time. Just try to explain to your insurance adjuster that you were just following what user "Iknoweverything" posted on a forum on how to hook something up, instead of checking your local code. See how far that gets you.

[AntAltMike]

Has anybody here ever read "the code". Last time I had a copy (either 1999 or 2002, I forget which) the mast had to be grounded with 10 gauge copper, 8 gauge aluminum or 17 gauge copper clad steel, it didn't have to be insulated, and it didn't have to be solid.

The coax outer conductor, however, had to be grounded with solid, insulated copper wire approximately equal in current carrying capability to the outer conductor itself (which no one knows) but under no circumstances can it be smaller than 14 gauge. When I checked with some local cable companies twenty years ago, they were content to use 12 gauge solid for the coax grounding, and in another thread, someone who claimed to have his hands on a copy of the 2005 code swore that it no longer specified insulated for the coax outer conductor ground, but he did not publish an actual excerpt.

Once, in a dumbass college town, the electrical inspector made me get a low voltage license to install a satellite dish, and he said that since the current carrying capability of the coax outer conductor is determined almost exclusively by its outer diameter, the ground wire would have to be six gauge. I used six gauge stranded bare copper to make that ground connection, but fortunately, he didn't realize that technically, it still failed to meet two other requirements and he approved it.

I later told him that 6 gauge didn't have as large an outer diameter as the coax outer conductor and he said he realized that, but that it would serve no purpose for him to require anything larger than that since the bonding jumper from my ground rod to the ground electrode system conformed to code with six gauge, meaing that any larger ground wire before that would be superfluous, since it would be stronger than the weakest link.

I think it is riduculous that someone can actually "own" a law that we have to obey and force us to buy it from them to positively ascertain whether we are obeying it or not.

[Mike500]

#6 gauge is recommended in the code as heavy enough to be used without protective conduit in many codes.

#8 gauge is adequate for curent carring purposes, but #6 is usually used, since it meets code without enclosure in conduit.

[MONSTERMAN]

ugh, not more grounding/lightning debate AGAIN. :bang :icon_dumm

Agreed... I'm only looking for dissipating static charge from LNB's and Coax cables. I don't care about lightning (I'll play the odds). If I did care about lightning I'd get some lightning arrestors. Every time someone mentions "grounding" people automatically jump to lightning, jeez.

:nono:

[Villanman]

From my experience as a Career firefighter over the last 10 years,
If a house takes a direct lightning hit, there is a pretty good chance it will catch on fire no matter how well it's grounded. I've seen bricks actually blown off buildings from a direct hit and Lumber yards torched just from lightning hitting stacks of wood.