35
votes
Is it OK to create a third prong ground from a cold water pipe, for a 2-wire circuit?
When or is it NEC code compliant to upgrade a 2-wire circuit, by adding a third prong equipment ground from a nearby galvanized cold water pipe?
Never!
Article 250.118 of the National Electrical ...
- 20.5k
26
votes
Accepted
Is this box bonded properly to the ground?
I do a lot of work on older homes and see stuff like this all the time. Keep in mind that the equipment grounding conductor (EGC), that bare safety ground, was not always present in wiring systems. ...
- 25.2k
21
votes
Can ground attached to neutral fool a receptacle tester?
The tester can't tell the difference. One way to look at is that electrically, since neutral and ground are already bonded at one location (normally the main panel), the electrons don't know the ...
19
votes
Accepted
How do I check if my outlet's ground and neutral are connected correctly?
Neutral is not Earth
They are completely different wires with completely different jobs. Neutral is the normal everyday path for return current. Earth is a fault catcher, it only flows current when a ...
18
votes
Accepted
Are the grounds and neutrals in this electrical subpanel reversed?
Whoever wired this panel simply was not paying attention
The installer who wired this panel did not pay attention to the schematic on the label, assuming that removing the bonding strap was enough ...
- 85.1k
17
votes
Accepted
Does NEC allow a metal box to carry the ground connection between separate conductors?
This is fine
NEC 250.109 explicitly permits metal boxes to be part of the ground-fault current path:
Metal enclosures shall be permitted to be used to connect bonding jumpers or equipment grounding ...
- 85.1k
17
votes
Can I use a hose clamp to ground a wire to EMT?
There's the Code answer, and the practical one:
Start from NEC 110.2:
The conductors and equipment required or permitted by this Code shall be acceptable only if approved.
Approved means listed and ...
- 12.4k
15
votes
Changing out GFCI disconnect for new hot tub
Neutrals and grounds are kept separated everywhere except at the main panel.
- 28.3k
13
votes
Can ground attached to neutral fool a receptacle tester?
Yes, it will misread. Because magic-8-ball testers are built for one thing: a quick pass/fail test for brand new wiring you just installed.
Obviously, in new wiring, you don't have a bunch of the ...
13
votes
Sub panel install issue
I'd be seriously tempted to email that picture to the licensing board...
I assume from your question that this was installed, incorrectly, by licensed electricians.
Buy a ground bar to fit your panel, ...
- 223k
11
votes
Accepted
Why is it required in some countries to sleeve uninsulated earth wire in junction boxes, but not required and not practiced in other countries?
On one hand it improves safety very marginally... on the other hand it escalates time and cost. Simple as that. In marginal-benefit cases like this, every country makes that call in their own way.
...
11
votes
Am I supposed to ground the breaker box itself?
All metal boxes get grounded first
So yeah. If you're sticking an outlet in a metal box and you have your Romex coming in, you don't take the ground to the outlet like you do in a plastic box. You ...
11
votes
Accepted
Best, and acceptable, connector for 12 to 20 ground wires in a junction box?
You could hang 4 (or more) "greenie" wire nuts off a wire connected to the ground screw. The greenies have a hole for one wire to pass through, as they are only for ground connections. Then ...
- 223k
10
votes
Does adding an explicit ground wire to EMT conduits provide any advantages?
If the conduit might be damaged because it is run somewhere you might step on it for example then an explicit ground wire is required.
Otherwise the upside is that you then don't have to rely on the ...
- 12.8k
10
votes
Does NEC allow a metal box to carry the ground connection between separate conductors?
ThreePhaseEel clicked Post before me, but here's what I was working on...
Metal extension rings are self-grounding when installed properly. They are treated as part of the box. As long as you re-...
- 6,799
10
votes
Accepted
Can I use a hose clamp to ground a wire to EMT?
To give a bit on insight, electrical connections are degraded by oxidation of the conductors. If two bare metal conductors have a good, low-resistance connection at first, the resistance between the ...
- 548
9
votes
I have 11V between neutral and ground, how can I isolate the problem and solve it?
What's up with all the voltage drop?
Easy. You have a 2.5mm2 cable (~13 AWG) going 50m (160'). That's a very small wire for such a long distance. In Canada you would not draw more than 15 amps on ...
9
votes
Accepted
Does this "creative" grounding meet 2017 or 2020 NEC?
Three 8' ground rods with #4 copper is all the Grounding Electrode you'll ever need for any conceivable residential service. However the run of copper wire must be continuous from the closest rod ...
9
votes
Accepted
How is a Ufer ground attached to the panel?
You will connect a bit of rebar to the reinforcement of your foundation and leave it sticking out of the concrete, that will be your ground connection.
Internal to the concrete you will need larger ...
- 12.8k
9
votes
Do the EGC and GEC both terminate at grounding bar in new sub-panel in detached building (garage)?
Great question, well formed. You clearly understand much of this. In my answer I'm not going use abbreviations so I can be very clear.
The 2 hots obviously go the 2 hot lugs, the neutral conductor ...
- 158
8
votes
Are the grounds and neutrals in this electrical subpanel reversed?
understand the logic behind Bonding the Neutral and Isolating Ground
the green earth ground or bare copper always connects to the metal of the panel box, or any metal that you touch.
the [white] ...
- 1,252
8
votes
Accepted
Is my main panel improperly bonded?
It's bonded, alright
Meter-main boxes like yours have their neutral bars permanently bonded to the case at the factory, and thus have a notation on their label saying that they are "suitable only ...
- 85.1k
8
votes
Accepted
Should my new service panel be bonded?
You are correct--the panel should not be bonded. Most panels will come with a bonding screw in case it is being used as a main panel and first means of disconnect, which yours isn't. When you install ...
8
votes
Should a subpanel in the same building have its own grounding rod?
No, you don't need separate grounding rods for a sub-panel in the same building. It just needs a 4 wire circuit (appropriately sized): 2 hots, a neutral and a ground. As always, the neutral and ...
- 23.2k
8
votes
What types of conduit would be appropriate to extend a circuit inside a storage bench?
I'd use the blank cover with the knockout and a 90 degree MC connector (shown below) and run the MC stapling it to the edge around the storage bench. Then terminate it in a metal old work box. Connect ...
- 83.7k
8
votes
Accepted
Upgrading 240v 3 prong dryer outlet to 4 prong
The ground wire coming off the cable must go to the metal box first. That's a Code requirement.
If it is competently attached to the metal box using a feature intended for that purpose, you're all ...
8
votes
Does adding an explicit ground wire to EMT conduits provide any advantages?
EMT for ground relies on
Scratching the paint off, adequately, from breaker panels or other painted boxes to which it is attached,
Set screws being tight, rust-free, etc.
the system remaining intact ...
- 43.4k
8
votes
Best, and acceptable, connector for 12 to 20 ground wires in a junction box?
I have installed a ground bar before, really didn't seem worth the effort or cost. Went back to just daisy-chaining wingnuts.
Never seen a big clamp that resembled a ground rod clamp listed for the ...
- 19.1k
8
votes
Accepted
Is the ground screw on this 4" round weatherproof box OK by code?
Pretty sure the language on screw threads for grounding mentions a number of threads engaged, NOT a specific thread pitch.
Here we go, under NEC 250.8, and the extra one for the UL mark:
Machine ...
- 223k
7
votes
Grounding 200A Main Panel with Changes to Water & Gas
Grounding Electrode System
You're going to have to install a grounding electrode system. This is typically done by driving two ground rods spaced at least 6' apart, and connecting the rods together ...
- 132k
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