Do I have to tie all grounds together?

ggunn

PE (Electrical), NABCEP certified
What you gain in fault clearing ability is about the same as flushing an eyedropper full of iodine down the toilet to help the city with sewage treatment.
Never in a million years would I use hyperbole to make a point. :D
 

david

Senior Member
It seems clear to me that all the conductors that are spliced should be connected together. In Trevors example, I would disagree with him and imo the #12 and #14 equipment grounding conductor's should be tied together.

I understand that the wording is fuzzy to some but I believe the intent is as I stated. I could be wrong
To me I don’t find the wording fuzzy and the intent seems clear your to maintain continuity

Between the all the equipment grounds in the box

If the box is metal the section gives you two options for continuity' tie all the wire equipment grounds together or bond them to a metal box. Or you could use a combination of both methods
 

goldstar

Senior Member
What I'm saying is that if you had two 12/2 cable and two 14/2 cables there is no reason that all four EGC need to be spliced together. If the box is metallic the largest EGC would connect to the box.
I agree. AND, if the JB contains a 15A switch and a 20A receptacle, you are not required to extend an EGC pig-tail wire to the device if you use self-grounding devices. In this case splicing all the EGC's together creates no heartburn.

Now, let's say you have a 3-gang NM box in an area serving a kitchen counter and you're using copper crimp sleeves for the EGC's. You have a 12/2 in and out for the GFCI circuit,, a 14/2 in and out power feed for lighting and (2) 14/2's (or 14-3's) out for lights. That's a total of 6 EGC's (2-12's and 4-14's) (and the insulated conductors a total of 4 # 12's and 8 # 14's if the switches are s/p or 10 #14's if they are 3-ways). If you crimp all the EGC's together and leave pig-tails for the (3) devices, what would be the proper size EGC to each device ? Would it make a difference if all the EGC's are crimped together ? I'm only asking these questions because we run into these situations all the time and it's a real PITA working with # 12's in this situation. Aside from the wording in 250.148 crimping all the EGC's together in this scenario gives me heartburn .:cool:
 

Dennis Alwon

Moderator
Staff member
I would pigtail a #14 equipment grounding conductor to a device on a 15 amp circuit. I would use #12 for an equipment grounding conductor for a device on a 20 amp circuit
 

jaggedben

Senior Member
There is a clear answer. You must tie them all together, and to the box if it's metal. (Is the box metal? You didn't say.) Go back and read the code section Dennis posted.
 

jxofaltrds

Senior Member
Arranged.

(D) Nonmetallic Boxes. One or more equipment grounding
conductors brought into a nonmetallic outlet box shall be
arranged such that a connection can be made to any fitting or
device in that box requiring grounding.
 

ptonsparky

Senior Member
What you gain in fault clearing ability is about the same as flushing an eyedropper full of iodine down the toilet to help the city with sewage treatment.

What you loose is some management of the wires in your junction box.
one drop for every flush times flushes per day times each flushee should help.
 

david

Senior Member
There is a clear answer. You must tie them all together, and to the box if it's metal. (Is the box metal? You didn't say.) Go back and read the code section Dennis posted.
if i bolt a groundbus to a metal junction box and land my equipment grounds that is fine,

it is also fine when i have gang-able device box fold an equipment ground and the loop on a ground screw creating two tails bonded to the box twist three equipment grounds to each of the tails that is also fine

i can move to the next green ground screw do this as many times as i would like some sets copper to copper bonded to the box. some sets would be bonded together by the metal box

The section allows for either of the bonding methods
 
I think the operative phrase here in the code is " grounding conductors associated with those circuit conductors" It seem to me that the 14 and 12 wire are NOT associated with one another.
Just my opinion.
 

RD35

Member
From an engineering perspective I can see a logical reason for the requirement. If a short circuit happens, say on the 15A circuit, and the #14 grounding conductors are carrying that fault current back to the panel then there is usually a pretty fair amount of voltage drop happening as it flows due to the high current. This voltage drop would be measurable between the #14 grounding conductors that are transmitting the fault current and the #12 grounding conductors that are not and both sets are inside the subject junction box. This could result in some arching (small as it may be) between the grounding conductors (or metal parts) as the potential on the grounding circuit is looking for any other path possible to get back to the panel. By bonding them all together, this potential is eliminated and the fault current path is improved which aids in clearing the fault sooner by allowing a higher current flow for tripping the breaker on short circuit. My 2 cents FWIW.
 

Eddie702

Member
They do not Have to be connected together. You can go in and out of a box with any number of cables and the grounds may be connected together or the grounds may be connected to the box with ground continuity through the box itself.

It's not the usual way but I have done this on occasion when I am adding a cable to an existing box and the existing grounds are twisted and connected to the box and are short making connection difficult. I just add a new screw to the box and ground the new cable.
 
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