# How dangerous is two wires under one screw?



## Gigs (Oct 26, 2008)

Two wires one screw sounds like one of those gross-out sites. 

Anyway turns out my house has a lot of outlets and switches with two wires under one screw, often with the stab also used. The builder did this, and I guess the inspector was OK with it too.

I know it's a violation, but is it really very unsafe? I'm trying to decide whether I should actively go through and check and fix every one, or just replace them as they wear out normally.


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## 220/221 (Oct 9, 2007)

Depends on the device. If it has a tab under the screw, it is designed for two wires.


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## Gigs (Oct 26, 2008)

220/221 said:


> Depends on the device. If it has a tab under the screw, it is designed for two wires.


These are just normal cheapo outlets. I have a box of spec grade that can clamp 4 wires on each side that I'm replacing a few of the higher-use ones with, but I'm still torn on whether I should go through the hassle of checking every outlet. The house was built on 1999 code cycle so there's a lot of outlets.


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## 220/221 (Oct 9, 2007)

So, they ran 3 or more cables into a recep box and wrapped two wires under a screw?

That was stupid. It doesn't take any more time to do things right.

If the conditions were *perfect*, I think it would be safe but I wouldn't trust someone that did an installation like this.


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## Stubbie (Jan 7, 2007)

I never cared for connecting a bunch of wires to a receptacle. If 12 awg four wires or more (don't forget the ground) to the receptacle makes it a PITA to push back into the box. I'd just pigtail everything to the receptacle.


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## Gigs (Oct 26, 2008)

220/221 said:


> If the conditions were *perfect*, I think it would be safe but I wouldn't trust someone that did an installation like this.


My wiring seems to have a split personality. Whoever did the panel and ran the rough in seems to have done an excellent job... the devices are another story. It's like they got a real newb apprentice doing it without any supervision.


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## jcalvin (Feb 6, 2008)

Gigs said:


> My wiring seems to have a split personality. Whoever did the panel and ran the rough in seems to have done an excellent job... the devices are another story. *It's like they got a real newb apprentice doing it without any supervision*.


Probably did. You can hire a kid off the street to put in recepticles while the experienced man is doing switches, panels, and the other hard stuff and 90% of the time have nothing to worry about. The other 10%, like this case, you get a lazy one. Not sure that it WILL cause problems, but, I would make an effort to fix them. I would hate to stand in my yard while my house is burning wondering if the recepticles caused that.


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## Wildie (Jul 23, 2008)

For the time that it would take to wrap two conductors onto a screw, it would have been more cost effective, to use a better recept. with tabs! 
I would consider replacing the cheapo recepts. with good ones.
There's a good chance that doubled connections will come lose!


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## Billy_Bob (Sep 11, 2008)

Basically two wires under one screw when the screw down device was not designed for two wires could cause a poor connection.

Also screws not tight enough can cause a poor connection.

If the electrical device connected is something low amperage (wattage) like just a table lamp, then no problem.

The problem occurs with higher amperage connections. Higher amperage connections need a good connection and a tight connection. If these connections are not this way, then the connection can get warm, hot, or even melt and sparks will fly!

With an outlet anything can be plugged in. So best to install them for the max load anyone might possibly plug in. (Correctly per outlet manufacturers directions.)


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## Ultrarunner2017 (Oct 1, 2008)

I would only use the pigtail method, but if I had to, (like if I were replacing an old receptacle and the box wasn't deep enough for the pigtail connection) I would use the two screws on each side of the receptacle which are connected with the break-away tab instead of putting two wires on one screw.
It might work for #14, but I cannot see how it would ever work for two #12.
I absolutely will never use the "stab" terminals for anything.

FW


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