Jim Jensen
Well-Known Member
SURE WISH I had known about that driver, back when I drove my last ground rod !!! (cause I already had a cheapo HoboFreight SDS rotary hammer....!!!
Question about proper grounding; replacing old copper with PEX.
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Stick with 2waxhack
Ludington
Well-Known Member
I used a fence post driver...like:
https://www.homedepot.com/p/Everbilt-3-in-x-9-in-x-24-in-Metal-Fence-Post-Driver-901147EB/205960880
https://www.homedepot.com/p/Everbilt-3-in-x-9-in-x-24-in-Metal-Fence-Post-Driver-901147EB/205960880
Mitchell-DIY-Guy
Well-Known Member
Remember "ground rods" are NOT the only acceptable methods of grounding. There's also ground PLATES which are detailed in the electrical code. In addition to these ground rods and plates, if you want to ensure they are going to do a good job for you, you need to check them. The soil condition is important as is the resistance. Plenty of information on it on the web.
Years ago in another life, was troubleshooting a ground loop problem in a large computer system at a 100 year old print shop in the Denver area. The building's ground rods were sunk under the slab in the center of the building. Well, that soil hadn't seen moisture in decades and thus the resistance was simply too high. We had to create one outside.
Years ago in another life, was troubleshooting a ground loop problem in a large computer system at a 100 year old print shop in the Denver area. The building's ground rods were sunk under the slab in the center of the building. Well, that soil hadn't seen moisture in decades and thus the resistance was simply too high. We had to create one outside.
Industrial instrumentation and computer control systems can have big issues with ground loop problems. But also detached garages and outbuildings in residential and rural areas.
I purchased a rental property that had a detached garage about 10 years ago. The previous owner ran overhead electrical to a subpanel in the garage. Everything in the garage was working fine, but when the city inspector checked out the receptacles in the garage, they all showed an open ground or open neutral, I can't remember which. When he left, I check the subpanel and it looked like it was wired correctly. I assumed the previous owner had switched the ground with the neutral in main panel, so I switch them in the subpanel as that was easy to do. I checked a receptacle, and it then showed an open neutral or an open ground, the opposite condition from the first check, whatever it was. I checked the main panel, and all was correct. I added two new ground rods for the ground buss in the subpanel, and everything checked out fine.
I purchased a rental property that had a detached garage about 10 years ago. The previous owner ran overhead electrical to a subpanel in the garage. Everything in the garage was working fine, but when the city inspector checked out the receptacles in the garage, they all showed an open ground or open neutral, I can't remember which. When he left, I check the subpanel and it looked like it was wired correctly. I assumed the previous owner had switched the ground with the neutral in main panel, so I switch them in the subpanel as that was easy to do. I checked a receptacle, and it then showed an open neutral or an open ground, the opposite condition from the first check, whatever it was. I checked the main panel, and all was correct. I added two new ground rods for the ground buss in the subpanel, and everything checked out fine.
Ludington
Well-Known Member
I may have to do that for my shed.
But it connects back to my main box, but it only has one large connection block for both.
I'll have to look up how to check that.
So, if you are saying that your neutral and ground buss is the same, that is not up to current code, but is not something that you absolutely need to correct. There are millions of houses out there which still have that. And with that condition, I'm not sure it will show up as a problem on a receptacle checker.
Mitchell-DIY-Guy
Well-Known Member
Are you sure about that? What I learned is that the transformer that serves a home (could be pad mount or pole mount) is grounded. That ground at the transformer is the neutral wire coming into a typical home, where three wires come in: neutral, and two hots. Hot-Hot is 240. Hot-Neutral, 120. In the primary (first) service panel, the neutral bus and ground bus are tied together. The neutral wire from the pole transformer or pad transformer is tied to the neutral bus bar. The grounding bus bar in the box is bonded or tied to the neutral bus bar. Thus in the first and primary service panel ground and neutral there are the same.
HOWEVER, all sub panels must have the grounds and neutrals unbonded; a separate neutral and ground wire must carry back from these panels (and indeed, from every fixture, or outlet, etc.) to the main panel. Neutral and ground are always separated EXCEPT when these wires reach the main panel.
Every primary panel I've seen has been like this. I've caught in inspections, the occasional sub panel where the neutral and grounds are bonded there, and that's a no-no but easily corrected.
Maybe I was taught incorrectly, or maybe there's an update to the code.
The AHJ at my rental house required an exterior service disconnect, and the 2020 NEC now required exterior service disconnects as well. That means the neutral and ground busses need to be separated at the main service panel where your house's breakers are located.
Mitchell-DIY-Guy
Well-Known Member
Exterior service disconnect required in MA. In the old days all you had to do was twist off the seal and pull the meter. I don’t think the new meters are that simple.
Ludington
Well-Known Member
That may be code, but never made a lot of sense to me, if it all goes back to the same point, what's the problem. There must be some reason for it.
Electricity ALWAYS takes the lowest resistance to ground. But the ground wire and ground buss should not routinely be current carrying. If the ground and neutral wiring are connected, current can theoretically energize the ground wiring even without a fault event.
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Mitchell-DIY-Guy
Well-Known Member
If you have the neutral and ground bonded or connected at a subpanel, then you'll have neutral return current through the ground wire back to the primary panel. If the neutral has a fault, everything will continue to work but you'll have all the current on the ground, which also means that you can now be electrocuted by touching the panel chassis.
https://www.finehomebuilding.com/project-guides/wiring/separating-grounds-and-neutrals
As @MicEd69 points out, new code adopted by many AHJ based on 2020 NEC now requires an external disconnect at the meter. This is NEC 2020 230.85 Emergency Disconnects.The reasoning behind it is to prevent injury to first responders. In old school meters, it was always incredibly easy to simply remove the wire sealing tag, and pull the meter; that served as a disconnect. Many modern meters I've seen seem to have these locked these days, and that old trick doesn't work.
While I have never seen one "in the field", here is a typical example. Note that the meter is "locked"; it doesn't have that little wire tag thing. The disconnect is just a big-ass switch. Electrically speaking in terms of grounding etc. however, this disconnect is in a sense, now the primary service panel, and the panel with the breakers is a sub-panel. As @MicEd69 points out doing things currently to code would require that the actual main panel--the one with all the breakers--would have to have the neutrals and grounds separate, whereas inside this outside switch box, they come together.
We had some homes here in our subdivision built in 2020-2021, and I'll have to see if they have this or a similar disconnect. Just because the NEC rewrote the rules in 2020 doesn't mean everyone adopted them immediately.
Ludington
Well-Known Member
So, if you have a subpanel being supplied by a 30 amp breaker, you have your 2 hot wires, neutral and the ground comming in. So you really need a 10/3 wire . Makes sense.
I just finished adding a subpanel and used 4 wire copper to the main panel removed the bonding screw in the subpanel.
Followed advice from my brother who was a licensed electrician for 40 years.
Followed advice from my brother who was a licensed electrician for 40 years.
Mitchell-DIY-Guy
Well-Known Member
Yes, 10/3+Ground...but it can be a little more complicated...
If your sub panel is far away from the main, there are other considerations and 8/3+G may be indicated. Always best to go with heavier wire than run "at the limit" with smaller gauge.
There are these things called ampacity calculations...
Ludington
Well-Known Member
Yes, I am aware. But thanks. My subpanel is about 100 feet away to my outbuilding. I put it in back in 2005. Havnt had any problems. But I don't remember what wire I did use. Going to check that today. (Not
that I'm going to dig that trench back up.) Put a pex airline out there too. Never had a problem with leaks in that. Condensation yes. But no air leaks. Had to put in a couple separators and a dryer. Don't want waiter in the air when your spraying lacquer .
My office is an outbuilding and we used two hots, neutral and a ground. Mobile home feeder cable.
No problem with #10 for 30-amp underground feeder 100 feet long.
And the neutral and ground busses are isolated like they should be, correct?
