DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   Electrical (
-   -   Bridging Ground wires. (

Duppy 01-16-2007 11:29 AM

Bridging Ground wires.
I have a 3 gang box with 4 cables: power in, power out to a GFI, power out to vanity, power out to vent fan/light. Three switches: 1 to vanity light, 2 for vent fan/light combo.

So this creates 7 ground wires which obviously won't fit into a wire cap. Is it safe to run 3 grounds into a cap, 4 into another and then bridge them with another wire between the 2 caps? If not what would be a better option?


Duppy 01-16-2007 12:35 PM

I guess just twisting all 7 together?

jproffer 01-16-2007 01:12 PM


I guess just twisting all 7 together?
There ya go. Ground wires don't necessarily need to be connected with wire-nuts. Just make sure they are twisted together WELL (more than a couple loose twists), I would use linemans and put 4 or 5 tight twists in them and call 'em good.

Another thing you need to think about is box fill. Ground wires aren't counted as far as CODE box fill rules, but common sense has to play in there somewhere. Just another thought.

Duppy 01-16-2007 01:52 PM

It is getting crowded in there even though it's a deep box. I have nowhere really fit for a junction box to where it would be accesible.

I could run 12/3 to the vanity and put the GFI after that, which would remove the one unnecessary cable from the box.

Now is that a legal route? Box to Vanity, Vanity to GFI, GFI to Switch, and Switch to Can Light in shower?

jproffer 01-16-2007 01:57 PM

Wow. I didn't even see all the things you had going on there. I don't know if it's even legal to have bathroom lights on the same circuit as the GFCI rec. (Hair dryer trips breaker, lights go out...trouble ensues).

Consider this: Nothing says the J-box has to be in the same room as the fixtures/rec it feeds, just that it must be accessible.

Duppy 01-16-2007 02:02 PM

The only light on the GFI would be the can light in the shower, the vanity and the light on the vent are before GFI.

Duppy 01-16-2007 02:38 PM

My interpretation is that as long as the bathroom has a dedicated 20Amp circuit you can put everything on it. If you are sharing the circuit between bathrooms then only receptacles may be on the circuit and lights need to be separate.

I could be mistaken.

Duppy 01-16-2007 03:03 PM

Nope found it.

The bathroom receptacles must be on a dedicated 20-ampere
circuit with no other receptacles or lights on it. Section 210-11(c)(3). An exception to this rule is if a 20-
ampere circuit is run to each individual bathroom, then you are allowed to have the bathroom lights on the
circuit also. Section 210-11(c)(3)(Exception). However, if one 20-ampere circuit feeds more than one
bathroom, no other receptacles or lights shall be on it.

Thank you for the advice on the grounds and the J box.


darren 01-16-2007 04:05 PM

Hey there, obviously i don't know what kind of device box you are using but most i have seen have 2 ground screws per box for a total of 6 ground screws. You can usually put 2 grounds under one screw so there would be 12 in total for you.

Now your device box could be differnt, if it is i would put as many as i could under the ground screws, leave the last one long and make a joint with the rest and put a marrette on it.

Hope this helps.


jwhite 01-16-2007 05:23 PM


Originally Posted by darren (Post 30199)
You can usually put 2 grounds under one screw so there would be 12 in total for you.

I hope you didn't learn that in your electrical school. I know it is illegal in the USA and I imagine in Canada as well.

joed 01-16-2007 05:53 PM


Originally Posted by jwhite (Post 30217)
I hope you didn't learn that in your electrical school. I know it is illegal in the USA and I imagine in Canada as well.

Nope Grounds have little ridge on each side of screw to hold wire under screw. You can put two wires under each screw by only inserting under one side of screw.

jwhite 01-16-2007 06:44 PM

must be a Canada thing. it would violate 110.14 of the NEC.

Duppy 01-17-2007 09:22 AM

Thanks for all the reply's. I'm using plastic boxes though so no ground screws. I think I'll just continue the power through the vanity light to the GFI receptacle, instead of running power to the GFI from the 3 gang box. That will alleviate the box fill issue as jp suggested.

Stubbie 01-17-2007 06:31 PM

May I suggest a wago connector. These will accomodate 8 ground wires. No twisting just push them into the connector.


All times are GMT -5. The time now is 12:05 PM.

User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1