A grounding question please

[MedMan4040]

I've today run 3/8" copper braid from my 'shack' area through a wall, above a drop ceiling
and to the outside where a copper bus bar awaits.
This bus bar runs to my whole house main electrical grounding bar......so everything will be grounded
at one point.
My question is simply how to connect the copper braid to the copper bus bar.
The copper bus bar has many screws in holes seemingly designed for ring terminals, yet the copper braid
I received has no terminals of any kind.
Suggestions please.

 

[prcguy]

Any reason you chose braid instead of wire? The braid will wick in water and corrode prematurely outdoors. Insulated wire of 10ga or larger should meet code and be much easier to run through walls, etc.

 

[MedMan4040]

Prcguy, for some reason I thought braid had advantages over strap or wire, but I'm game to anything...just wanting to be safe(r) than I was before which was NO grounding at all (been using VHF rigs) but passed my General yesterday and will begin putting up an EFHW soon for an FT-710 which has been sitting here for 2 months never turned on.
The braid wasn't hard to run at all and I could go to Lowes and grab some 10 gauge wire. So how would you terminate it? Simple ring terminal? I suppose one could even use Romex....got plenty of 12/2 in the garage....nope, just Googled. Romex is not even an idea choice for grounding.

 

[KF0NYL]

10 gauge is the minimum size that you should use. bare 6 gauge wire is usually recommended. I did use 10 gauge wire to connect my lightening arrestors to the ground rod. I used 6 gauge for grounding my antenna masts and also to bond everything to my service ground.

I agree that braid is not the best for outdoors use. The main reason it is used on vehicles is the flexibility factor so it doesn't break under constant movement.

 

[prcguy]

Prcguy, for some reason I thought braid had advantages over strap or wire, but I'm game to anything...just wanting to be safe(r) than I was before which was NO grounding at all (been using VHF rigs) but passed my General yesterday and will begin putting up an EFHW soon for an FT-710 which has been sitting here for 2 months never turned on.
The braid wasn't hard to run at all and I could go to Lowes and grab some 10 gauge wire. So how would you terminate it? Simple ring terminal? I suppose one could even use Romex....got plenty of 12/2 in the garage....nope, just Googled. Romex is not even an idea choice for grounding.

Short runs of flat braid is better for RF grounding because it has less inductance than round wire of similar thickness. But the type of grounding you are doing is more for meeting NEC for human safety placing all components of your station at the same ground potential. No real need to go larger than 10ga in my opinion since you won't be protecting from a direct lightning hit, that's not something you can realistically build for.

 

[KF0NYL]

Nothing is going to survive a direct lightening strike.

Here is a good article to read on grounding.

https://reeve.com/Documents/Articles Papers/Reeve_AntennaSystemGroundingRequirements.pdf

As always, follow NEC regulations and local building codes when installing antenna masts/towers. This includes proper grounding.

 

[AC9KH]

So how would you terminate it? Simple ring terminal?

I wouldn't use ring terminals. Just use screw lugs. They are available with a hole to bolt the lug to your bus bar, then simply insert the end of the wire in the lug and tighten up the screw. Ones like these - they're available in aluminum, bare copper or plated copper. Then treat the connection with some anti-corrosion compound which is used, for instance, when terminating aluminum conductors on a plated copper bus.

 

[AC9KH]

This bus bar runs to my whole house main electrical grounding bar......so everything will be grounded
at one point.

A lot of hams tend to over-think shack grounding and create their own ground loops, which it sounds like you're doing here. If you ohm out the power supply for your equipment, which is likely equipped with a three-prong power plug, that is already grounded to your service entrance. And there's likely an external chassis grounding point on the power supply. Ohm that out from the ground pin on the power plug to the chassis of the power supply and you'll likely find zero ohms.

All that's required to eliminate potential between your radio(s), tuner(s), etc is to run a grounding wire from each of those (daisy chained) to the ground point on the power supply and you're already connected to your service entrance grounding point. Why are you creating a ground loop with a second grounding circuit? The only reason to do what you're doing is if your station equipment runs off a battery so you have a floating ground, or you have some sort of cheap power supply with just a two-prong AC plug.

I would urge you to check this out with your handy ohmmeter before you go to great lengths to create a ground loop. There's a reason on AC power why only one neutral-ground bond is allowed in the system at the service entrance, and all subsequent sub-panels are not bonded. Power only flows on that service ground in the event of a fault, and it flows to that common grounding point. You don't want it flowing in loops, following the path of least resistance to get there - that will create differences in potential.

When you think of electrical grounding in AC power systems, reduce it to the simplest terms - every electrical item in your house or shack is grounded but there's only one path to that common ground from any item. Don 't create two paths or you got a ground loop, same as bonding the ground to neutral in a sub-panel with split-phase power.

RF grounding is different and that can't be bonded to your electrical service ground. So is antenna masts and towers different, they normally have their own grounding system to divert lightning or static buildup without running it thru your electrical service ground.

 

[davidgcet]

I wouldn't use ring terminals. Just use screw lugs. They are available with a hole to bolt the lug to your bus bar, then simply insert the end of the wire in the lug and tighten up the screw. Ones like these - they're available in aluminum, bare copper or plated copper. Then treat the connection with some anti-corrosion compound which is used, for instance, when terminating aluminum conductors on a plated copper bus.

View attachment 178895

those are not made for use in a wet location, though people often do. a true compression lug is best, and it "should" be a properly sized 2 hole lug. that means correct size for the wire, correct hole size for the stainless bolts, and correct hole spacing for the bar. you can roll the end of the braid up tight to crimp on a lug, BUT it will never be perfect. i personally would tin the braid after i rolled it, crimp a lug on and then solder it to the braid. probably overkill but won't hurt in my experience. the lug you posted is for solid wire in a protected area, but if he does have to use one like that i would cold galv it once everything is locked in tight.

 

[AC9KH]

those are not made for use in a wet location, though people often do

They are for stranded or solid wire. They're used all the time in wet or outdoor applications, including in Siemens 600V rated three-phase knife switches right from the factory. This is a Siemens outdoor safety switch that uses lugged fuses instead of blade contact type. The reason they use those is because blade contact fuses will rust the tension springs on the blade contacts, and subsequently melt and burn the contacts.

This is for an application on a 60hp three-phase motor with no soft-start and due to the inertial load it takes it 9 seconds to spool up to operating rpm, drawing 1,000+ starting amps. So they use lugged slo-blows because a conventional three-phase motor starter won't handle the starting amps. There's a safety flash cover that goes over the whole assembly. If the motor loses a phase during spool-up it's about like a 12ga shotgun going off when one of those fuses blow.

The same lugs are used in the top of the box where there's three stranded copper THHN conductors feeding it.