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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 Code lists the approved methods of equipment grounding. Water piping systems are NOT listed there.
Metal piping systems within buildings are required to be bonded ...
24
Yes, in most jurisdictions.
NEC 2014
The 2014 version of NEC has made a change to 250.130(C), which now allows you to connect to the equipment grounding conductor of another branch circuit, as long as it originates from the same enclosure. The new text reads as follows:
National Electrical Code 2014
Article 250 - Grounding and Bonding
VII. ...
18
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 difference. But the other way to think about it is to look at what the tester is actually doing.
What do the Lights Indicate?
These testers are actually 3 simple ...
10
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 kinds of problems you have in old wiring, like people bootlegging ground off neutral. The device is simply not made to solve those problems.
So if you misuse ...
7
It turns out that between the 2011 NEC (which Tester101 cited) and the 2014 NEC -- the answer to this question changed! Under current (2014) code -- a new point 4 was added under 250.130(C):
(4) An equipment grounding conductor that is part of another branch circuit
that originates from the enclosure where the branch circuit for the receptacle
or ...
7
It sounds like this is what you're describing...
If this is indeed what you've encountered, you should remove the grounding conductor from the twist-on wire connector used to connect the white wires.
The only place grounded (neutral) conductors and grounding conductors should be bonded (connected), is at the main service disconnect.
If there are no ...
7
Sounds like you have an improperly bonded neutral somewhere. If it isn't easily identified at the main service panel, you'll want to do a couple of things:
Call your electrical company and request (or if necessary demand) that they check to make sure the incoming neutral wire is grounded correctly on their side of the service.
Make sure that the water ...
7
If you're in an area that has adopted National Electrical Code, you'll have to run a 4 wire feeder. You'll also still need the ground rods at the shed, which you'll bond the grounding bar in the panel to.
If it's an existing 3 wire feeder, and there are no other conductive paths between the buildings. Then yes, you'd bond the grounded (neutral) bar. However,...
7
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 feeder(s) or branch circuit(s), or at a separately derived system shall be installed as specified in 250.64(A) through (F).
(C) Continuous. Except as ...
6
Look for the Pal nut on the other end holding the ballast to the metal housing it's mounted on. It's made to bite through the paint to ground the ballast to the housing which is then grounded.
For safety, it's more important that the metal housing you will touch be solidly grounded than the ballast which is inside and protected from direct contact be ...
6
My guess would be that because the fixture has a metal frame, the ballast is grounded via its contact with frame. If the frame were plastic, you would need to use the terminal on the ballast.
If you're converting it to hardwired, you should definitely connect the ground wire to the grounding screw.
You're also going to need to cut a hole if there's no ...
6
The new 30A panel needs a 4-wire feeder from the 60A panel. This is two hots, a neutral and an equipment ground.
The remote 30A panel also needs a grounding electrode (or two) since it is in a detached structure. This grounding electrode has NOTHING to do with the equipment ground run with the feeders. The two serve very different purposes.
In the ...
6
Conduit (RMC, IMC or EMT) is an NEC-accepted ground path. So, if the wires are in steel conduit, no OTHER ground wire is required.
If that gives you concerns, you might find this link reporting research into the effectiveness of conduit as a ground relieves them.
https://www.nema.org/Technical/Documents/Steel%20Conduit%20and%20EMT-Proven%20to%20Meet%20the%...
6
First off, why is the ground #6? Seems big unless the circuit is over 60A.
Personally, as Tester commented, I'd use a double lug screwed to the box via a machine thread screw, that is if you can find one small enough. The one Tester linked is quite large for the application. Smaller ones might be hard to find though.
This one is the smallest I could find:
...
6
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 using a properly sized bonding jumper. Then you'll install a properly sized grounding electrode conductor, from one of the ground rods back to the main ...
5
You're going to want to connect the fixture grounding conductor directly to the supply grounding conductor, using either a twist-on wire connector or crimp connector. You'll also want to use a pigtail, to connect the supply grounding conductor to the grounding screw on the metal box.
You should not rely on the support straps attachment means to provide an ...
5
Metallic Boxes
If it's a metal box, technically, the grounding conductor should be connected to it (NEC 2011 250.148(C)). However, if you've already installed the fixture without bonding it, it's not likely to cause a problem. If the fixture itself is properly grounded, and the canopy completely covers the box. It's not likely anybody will ever come into ...
5
The bare copper wire and any green insulated wires are meant to be connected together, making it a "party of three" as you stated in your question. That said there is another consideration to take into account as well. These safety ground wires are also meant to be connected to a common ground point of the electrical box as well.
If one of these wires (...
5
Because your water heater has dielectric unions, so the hot and cold plumbing are isolated from each other. Bonding the plumbing, attempts to keep the hot and cold plumbing at the same electrical potential.
If this bond is not in place, it's possible for the hot and cold plumbing to be at different voltage potentials. Which means if you grab a hot and ...
5
RCDs. Done.
An RCD detects ground faults, which includes "electrical shocks to humans".
In Europe, there are several types of RCD in general use - whole house and individual-circuit. RCDs which protect humans should trip at around 8 milliamps, give or take. RCDs designed to protect the house (not the humans) are rated higher, at 35 milliamps give or ...
5
The tester will show "correct". Opening the outlet is the only way to check it that I know of.
5
You must buy lugs either way. Do it right.
You can't double-tap a lug. You can buy "staircase" lugs that are 1-lug width but provide 2 lugs, but you can't torque one without removing the other. And they may not fit on your breaker. In that case, you'd use 3-lug Polaris connectors.
Regardless, these don't come in small-large-large, so you'll have ...
4
Congratulations, you've created an open (floating) neutral.
"I omitted the neutral and ground from the main panel... I hammered a new ground rod and bonded the ground and neutral at the new building sub panel, which I figured would give me the same setup as a main panel..."
This is partially incorrect. The main panel should be supplied from the utility ...
4
Lamp cord typically comes in 18/2, and 16/2 varieties. Neither of which has a grounding conductor. If the lamp...
is intended to be used indoors
will connect to the electrical system through a cord-and-plug attachment means
Does not have any exposed metal parts
you should be fine using a 2 wire attachment cord. However if the lamp...
will be used ...
4
If you are running 4-wire from the 60A to the 30A, and the 60A is connected correctly, you already have "a neutral return to the service entrance" in the form of the neutral wire feeding the 60 A box.
The ground and neutral bars at both sub-panels should be separate (with the Neutral isolated from the box), and the Neutral wire should be connected to the ...
4
National Electrical Code does allow metallic conduit and tubing to be used as an equipment grounding conductor, as long as it's installed properly.
However, before using it as such in an existing installation, you should verify that it provides an adequate continuous path to ground.
National Electrical Code 2014
Chapter 3 Wiring Methods
...
4
This is a bigger can of worms than meets the eye. There are huge arguments over all this.
This is a coax grounding block:
This is a grounding bar:
This is a grounding bridge, your cable company or telephone company probably has one on the outside of the house at the electrical service entrance:
What I'd do:
Run a ground cable from your ...
4
In North America equipment grounding conductors (circuit grounds) can be much smaller than circuit conductors. In fact it's only the first few circuit sizes (up to 30A) that require the EGC to be the same size as the circuit conductors.
In the US, grounding conductors are sized according to the NEC Table 250.122.
4
In the 2014 NEC handbook there is an exhibit 250.22 that shows this case. There is only 1 wire coming from the electrode to the panel. I would have said this would not be code compliant but it is clearly shown that the wire from the grounding electrode can run to the pipe saving a bunch of wire in some cases. Good Question!
4
NEMA 10-30 receptacles are grandfathered, illegal for new installation but legal to leave alone if already installed. It is not safe and it has a body count. It is legal because of lobbying by the appliance industry.
By modifying it you lose your grandfathering and make it illegal.
Your proposal solves the safety problem electrically, but mechanically ...
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