DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Electrical (http://www.diychatroom.com/f18/)
-   -   How do you handle all the grounding wires? (http://www.diychatroom.com/f18/how-do-you-handle-all-grounding-wires-12936/)

Piedmont 11-01-2007 02:13 PM

How do you handle all the grounding wires?
 
I have a 3 gang plastic box with 3 switches. So, I go to hook things up and realize I need to connect 7 ground wires together as, each switch wants to be grounded and each fixture that the switches run wants to be grounded as well, then you have the ground from the feed.

How do you handle all the grounds? I ended up having 2 wire nuts with 4 wires each connecting to each other and to each outlet, feed, and switch.

I suppose I could have hooked in 2 grounds into each light switch, that would prevent the need for 2 wire nuts.

Which do you do or am I making it more difficult than it should be?

Stubbie 11-01-2007 02:54 PM

What you did is fine and very common. My personal choice for homeowners is push connectors when connecting that many grounds.

http://www.gardnerbender.com/whats_n...f/PushGard.pdf

Piedmont 11-01-2007 03:16 PM

Thank you so much, it was relieving to hear it was normal as it didn't feel or look normal doing it.

Andy in ATL 11-01-2007 08:31 PM

The key here is you attached the nest-o-grounds to the switches AND EACH OTHER.

I've trouble shot many an open ground circuit where "highly qualified" electricians managed to get a bare wire to the switch but never made the connection between the two bundles.:furious: My phrase for the day is "CONTINUITY IS KEY!!!!!"

arichard21 11-02-2007 08:45 AM

i had a similar situation, and i used the crimp rings. got all my grounds bundled together, used the crimp ring, and cut off the remainder of the grounds i didnt need. if i remember correctly, i had 3 coming into a 2 gang box, and connecting to 2 outlets. i just bundled the 3 togher, crimp, cut 1 off and voila!

Andy in ATL 11-02-2007 02:54 PM

That is exactly how you do it. The problem comes in when you have too many wires for one sleeve. Then you MUST make sure that one wire makes it into BOTH crimp sleeves on the two bundles so the bundles are connected together.

yummy mummy 11-02-2007 04:39 PM

I also, have many ground wires in one box.

I was told that as long a one ground is connected to the green screw, and the rest of them are all connected together with the one that is on the green screw, that this is correct.

Is this correct?

Andy in ATL 11-02-2007 05:40 PM

Short answer: yes

Lets talk about what all those grounds are for. It is not so the electrons can go underground and party.:no: In a correctly wired modern home you have two ungrounded conductors (hot wires) and one grounded conductor (Neutral). The neutral wire is derived by attaching it at the midpoint of the windings on the transformer for the two hots. The neutral is also attached to the ground by the power company(POCO) before it gets to your house. In side the house the electrician runs his (or her:yes: ) branch circuits. In our example circuit for a family room, he will run a hot, a neutral, and a ground. Where the POCO's wires enter the house the ground wire and the neutral wire come together with the neutral wire from the POCO.

When a fault occurs, say in the ceiling fan of this living room (and by fault, I mean a hot wire touches a ground wire or something it is attached to) the ground wire provides a low impedance path back to the SOURCE. What is this SOURCE Andy speaks of? Put simply it is the midpoint of the windings on the POCO transformer mentioned above. The electrons want to go back to the source to party. It has not one honker thing to do with the plant Earth or those groundrods you have in the backyard.

So why is it so critical to have all these grounds connected together??? If the fault in the ceiling fan were to travel back to a receptacle and the ground that was attached to the SOURCE was not attached to the ground in the ceiling fan then all the metal parts on that recp. would now be hot. And say you were barefoot and standing on a grounded heating grate and you reached down and touched the screw holding the plate on you would likely be killed.

Now let's prove some of this with OHM's law.

In the NEC the electrician must drive a ground rod. If the ground rod has greater than 25 ohms resistance, he must drive another one. So in the NEC 25 ohms is the magic number.

I=E/R Where I=Amps E=Volts R=resistance

If we were to depend on the ground rod without it being attached to the SOURCE lets see what would happen on the ceiling fan example...

I= 120V/25ohms = 4.8Amps You would have 4.8A potential on that ground screw. On a 15Amp breaker 4.8A ain't gonna make the breaker trip. It takes MILLIAMPS to kill you.

If we were to attach the ground wires from the ceiling fan back to the source then lets see what would happen

I=E/R 120V/.001ohms(the resistance of the wire which by the way I'm pulling this number out of my butt because I don't know the resistance of the wire, but it is accurate enough to prove a point.) = 120,000A Which is enough to trip the 15A breaker instantly saving you and your family.

Did anyone learn anything, or was that a waste of time???:whistling2:

HouseHelper 11-02-2007 06:07 PM

Waste of time.:laughing::laughing:

Andy in ATL 11-02-2007 08:03 PM

Aww damn, your probably the only one who read it.

mdalli 11-02-2007 08:50 PM

Those push connectors are sweet... gonna have to remember those.

NateHanson 11-02-2007 09:01 PM

Are those push connectors more reliable than back-stab connections on a receptacle? I've always heard that back-stabs are prone to failure, and these would seem to be something similar. No?

SwiftyMcV 11-02-2007 10:34 PM

as an electrician I will say those push connectors are gimicky. If you ever move those wires around after abit of time the wires come loose form the connectors.

I know for a fact if you put it on a wire and twist it 5 times around it it comes loose.

Your best option... USE A BIG BLUE MARRET... not that hard to put on....

Stubbie 11-04-2007 06:57 PM

Quote:

as an electrician I will say those push connectors are gimicky. If you ever move those wires around after abit of time the wires come loose form the connectors.
Then maybe you should install them according to the manufacturers directions and stop twisting them around. You are certainly entitled to your opinion.. however ..They are a listed and accepted connection in your country and mine and I dare say the people who allowed the listing were a tad bit more qualified than you or I and did not consider them gimicky. Be aware that these people also are all too aware of the poor backstab design of the past.

Quote:

I know for a fact if you put it on a wire and twist it 5 times around it it comes loose.
Do tell......funny thats exactly what they are supposed to do in order for replacement.

Quote:

Your best option... USE A BIG BLUE MARRET... not that hard to put on....
7 grounds are not easy for a homeowner to put in a wirenut.... you know this as well as anybody here.

Stubbie 11-04-2007 07:15 PM

Quote:

Are those push connectors more reliable than back-stab connections on a receptacle? I've always heard that back-stabs are prone to failure, and these would seem to be something similar. No?
Hi Nate

Actually the push connectors use an entirely different method than the push in stabs on switches and receptacles. They are very reliable when properly installed. I would put much more faith in these for a homeowner dealing with 7 ground wires than with a wirenut and 7 wires. These are gaining popularity both in commercial and residential applications but I seriously doubt they will ever replace the wirenut. They have many handy uses with one being dealing with a short wire in a box on old construction and they work real well when connecting lighting ballasts. At any rate they are not the same as the back stab.


All times are GMT -5. The time now is 11:35 PM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved