69 votes

Why don't electrical receptacles have more than one ground?

This is because removing a device isn't allowed to interrupt grounding connections Removing a wiring device from the circuit cannot break grounding connections, or else you are violating NEC 250.148(...
62 votes
Accepted

Why is my garage grounded ONLY when it rains?

To me it sounds like the conduit was used as the grounding conductor, as allowed by code, and it rusted through, therefore it works when the ground is wet and you have a ground connection through the ...
  • 100k
51 votes

The main ground on my house sparks when an appliance is turned on

You lost neutral! This is an outage and an emergency Your neutral wire no longer connects back to the utility. Out of desperation, neutral is pathing through your neutral-ground equipotential bond, ...
40 votes

I live in an older home without ground wiring. Is it safe to install 3-prong GFCI with only a hot and neutral?

Absolutely! There are a number of different functions that an ordinary ground wire performs. A GFCI, despite the "G", does not actually need a ground wire to function. In fact, a properly ...
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 ...
  • 19.5k
30 votes
Accepted

The main ground on my house sparks when an appliance is turned on

If you see sparks at a ground rod, you have serious problems. Could very well be a lose or weak neutral and a lot of current is returning to the transformer via the ground rod(s). The more I think ...
27 votes
Accepted

What are these orange outlets directly attached to my breaker box?

That recep appears to be right next to your service panel, connected to the panel by a 1" conduit nipple. That makes it the "magic electrician's outlet". It's not required by Code. It's just a "...
27 votes
Accepted

Buying a home with 2 prong outlets but the bathroom has 3 prong outets

Grounding is no longer red-alert essential Since there are other ways now to provide better protection. Particularly, GFCI protection is so good that you're allowed to fit 3-prong outlets as long as ...
26 votes
Accepted

Why don't I have ground wiring on any of my outlets?

Your house is wired using the EMT conduit wiring method. Individual wires are carried inside metal conduit. The conduit is the ground path. Most commercial and industrial buildings look exactly ...
26 votes
Accepted

Is it safe to use the ground as a neutral when other grounds are available?

What could possibly go wrong? If the ground wire is bare copper, you massively increased the risk of a ground fault, which can kill somebody or burn the house down. If the ground wire has a smaller ...
  • 593
26 votes
Accepted

Why is 'Ground' important?

Answers provided so far are good, but I would like to add another very important aspect of ground. When looking at neutral vs ground, the question you ask is very natural. After all, both ground and ...
  • 296
24 votes

Why don't electrical receptacles have more than one ground?

I am glad you are finding it convenient that some devices allow themselves to also be used as splice blocks. However, that is prohibited for certain types of wires: Any and all ground wires ...
23 votes
Accepted

Looking for some guidance on knob and tube

Thus far, I've replaced the first receptacle in most of the series of receptacles with an AFCI/GFCI because I'm so confused. Don't do electrical work in a building owned by someone else. To do that ...
22 votes
Accepted

What purpose does a 3+1 outlet/circuit provide when the neutral bus is grounded?

Yeah, the root problem is, you see they are both tied together in the panel, but you don't know what that thing is... or you don't even realize that is a thing. Its name is the Neutral-Ground ...
22 votes

What does it mean if the electric is out in a room, but the breaker is not tripped?

Those outlet testers can be horribly misleading, there are multiple different faults that could cause any particular combination of lights and the ones they print on them are often not the most likely ...
  • 4,280
22 votes
Accepted

Why would bridging Neutral and Ground trip a GFCI breaker?

You created a ground fault. So it worked exactly as it should have. Rather than the current in the live and the current in the neutral being equal (or within 30 mA for most European RCCBs, 5 mA for ...
  • 146k
20 votes
Accepted

Safe way to remove paint from ground wire?

Just some sand paper will be fine. You don't want to use a chemical stripper as it may interact poorly with the copper.
  • 19.3k
20 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 ...
20 votes

What are these orange outlets directly attached to my breaker box?

The orange colored outlets are installed for an isolated ground. They are electrically the same as regular outlets, except they're built better and the yoke of the outlet is not tied to the grounding ...
  • 60.5k
20 votes

Why is my garage grounded ONLY when it rains?

An outbuilding needs two kinds of grounds Electricity wants to get back to source, not ground. Source is the supply transformer, or in the case of natural electricity (lightning, ESD), then yeah, it'...
20 votes

Where to land ground in main panel

You might as well just replace the whole panel There's absolutely no sense trying to hunt down the correct grounding bar for your panel -- it's a FPE Stab-Lok, whose breakers and busbars are both ...
19 votes

Can I use green wire in a residential wall box?

Green wire is perfectly legit. If you are really lazy or in a hurry you can even get pre-cut pre-stripped green grounding pigtails ready to go. Ground is the only thing it can be used for, but "...
  • 146k
18 votes
Accepted

Had ground rod connection added to my electric panel, should old ground to copper water pipe be disconnected?

No -- that bond wire could save your life! It is very important that all non-current-carrying metal, including the cold and hot water pipes, be bonded to the electrical system ground. This prevents ...
18 votes
Accepted

Why am I getting shocked by a water heater?

Filipino electrical service is a morass. There is some Euro 230V single leg service, and there is some American style 120/240 split phase service. And if those services are wired to Euro or USA ...
18 votes
Accepted

How to electrically ground a gas furnace connected with an armoured cable

Someone forgot a fitting Normally, armored cables (like yours) are brought into a box using a fitting designed to clamp the the cable armor, grounding it to the box and also providing a strain relief ...
18 votes
Accepted

How did my ground and neutral become energized by a short in the buried main line?

I think the power guy's assessment was spot-on He said it appeared that the buried cable coming in from the street had degraded or been damaged and that the "hot must have nipped the neutral." ...
  • 21k
17 votes
Accepted

What do I do with the ground wire in a smoke detector install?

That looks like a plastic box to me. If it is metal, code requires that the box be grounded. If all the external parts of the smoke detector are plastic then a ground is not required (the same is true ...
  • 100k
17 votes

Why is 'Ground' important?

Ground wires in receptacles perform two basic functions: Path for surge protection and other things that are not part of the regular circuit Complete the circuit in certain fault situations I would ...
15 votes

Dryer Outlet - 4 prong to 3 prong

Switch the cord, not the socket You have a proper NEMA 14-30 dryer receptacle with a ground wire, which is good. However, your "new" (old) dryer has a 3 prong (NEMA 10-30) cord. This can be ...
15 votes

Buying a home with 2 prong outlets but the bathroom has 3 prong outets

There are a few possibilities: The bathroom outlets were changed to three-prong and the ground screws are unattached. This means they're not grounded and are potentially unsafe. New wiring (or ...
  • 109k

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