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 ...
ArchonOSX's user avatar
  • 19.8k
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. ...
batsplatsterson's user avatar
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 ...
manassehkatz-Moving 2 Codidact's user avatar
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 ...
Harper - Reinstate Monica's user avatar
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 ...
ThreePhaseEel's user avatar
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 ...
ThreePhaseEel's user avatar
15 votes

Changing out GFCI disconnect for new hot tub

Neutrals and grounds are kept separated everywhere except at the main panel.
crip659's user avatar
  • 24.3k
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 ...
Harper - Reinstate Monica's user avatar
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, ...
Ecnerwal's user avatar
  • 214k
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. ...
Harper - Reinstate Monica's user avatar
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 ...
Harper - Reinstate Monica's user avatar
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 ...
Ecnerwal's user avatar
  • 214k
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 ...
ratchet freak's user avatar
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-...
Robert Chapin's user avatar
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 ...
Harper - Reinstate Monica's user avatar
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 ...
Harper - Reinstate Monica's user avatar
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] ...
ron's user avatar
  • 1,204
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 ...
ThreePhaseEel's user avatar
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 ...
Retired Master Electrician's user avatar
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 ...
George Anderson's user avatar
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 ...
JACK's user avatar
  • 80.5k
8 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 ...
ratchet freak's user avatar
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 ...
Harper - Reinstate Monica's user avatar
8 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 ...
george anderson's user avatar
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 ...
jay613's user avatar
  • 37.4k
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 ...
NoSparksPlease's user avatar
7 votes
Accepted

What can I do about a severed grounding wire?

Here is what the National Electrical Code says: 250.64 Grounding Electrode Conductor Installation. Grounding electrode conductors at the service, at each building or structure where supplied by a ...
ArchonOSX's user avatar
  • 19.8k
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 ...
Tester101's user avatar
  • 132k
7 votes
Accepted

Replacing subpanel that was fed with 3 wires

Your feeder appears to be in metal conduit, which is the grounding conductor Since your feeder appears to have been run as wires in a metal conduit, that conduit would serve as your grounding ...
ThreePhaseEel's user avatar
7 votes
Accepted

Grounding tv antenna in attic?

Good choice on the antenna. Lots of high quality reception for free. In fact, OTA (over the air) TV signals are often of better digital quality than TV through cable distribution. Cable TV is ...
P2000's user avatar
  • 16k

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