Ground Bars

[nizak]

If you have an equipment grounding bar that is marked as accepting a maximum #4 awg does that mean you can also install more than 1 conductor as long as the total circular mill does not exceed #4? Could someone point out the article that pertains to this. Thanks.

 

[infinity]

I would say nope.

110.14 Electrical Connections.
Because of different characteristics of dissimilar metals, devices such as pressure terminal or pressure splicing connectors and soldering lugs shall be identified for the material of the conductor and shall be properly installed and used. Conductors of dissimilar metals shall not be intermixed in a terminal or splicing connector where physical contact occurs between dissimilar conductors (such as copper and aluminum, copper and copper-clad aluminum, or aluminum and copper-clad aluminum), unless the device is identified for the purpose and conditions of use. Materials such as solder, fluxes, inhibitors, and compounds, where employed, shall be suitable for the use and shall be of a type that will not adversely affect the conductors, installation, or equipment.
FPN: Many terminations and equipment are marked with a tightening torque.
(A) Terminals. Connection of conductors to terminal parts shall ensure a thoroughly good connection without damaging the conductors and shall be made by means of pressure connectors (including set-screw type), solder lugs, or splices to flexible leads. Connection by means of wire-binding screws or studs and nuts that have upturned lugs or the equivalent shall be permitted for 10 AWG or smaller conductors.
Terminals for more than one conductor and terminals used to connect aluminum shall be so identified.

 

[Dennis Alwon]

If you have an equipment grounding bar that is marked as accepting a maximum #4 awg does that mean you can also install more than 1 conductor as long as the total circular mill does not exceed #4? Could someone point out the article that pertains to this. Thanks.

No, the cir mil has nothing to do with the number of conductors allowed but most bars will allow 2 conductors. I think that Cutler Hammers ground bar may even accept 3 conductors but I am not certain.

 

[nizak]

Thanks for the info, with that being said if only 1 conductor is allowed per opening than there are a number of new installs that are in violation of the code.I myself am guilty of the violation and have never been called on it in 10 or so years.

 

[Dennis Alwon]

Thanks for the info, with that being said if only 1 conductor is allowed per opening than there are a number of new installs that are in violation of the code.I myself am guilty of the violation and have never been called on it in 10 or so years.

Most often the panelboard will tell you that 2 conductors are allowed for egc not for the neutral conductor. The neutrals cannot be doubled.

408.41 Grounded Conductor Terminations.
Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.
Exception: Grounded conductors of circuits with parallel conductors shall be permitted to terminate in a single terminal if the terminal is identified for connection of more than one conductor.

 

[Split Bolt]

One additional thing to remember. If you do put 2 or 3 ground wires under one set screw, (when the bar allows) they need to all be the same size conductor. I have seen a #12 and a #14 under one screw and the #14 can be pulled right out, even if the screw is tight!

 

[jmellc]

I agree, try to not mix 12/14 or 10/12. Too easy for 1 to slip. I also try to keep a few ground bars from old panels (if in good shape) and add to a panel sometimes if bar is too crowded. An IG bar kit is good if you need to expand a neutral bar. Also, with new bars, you have some choice and can often put them in a less crowded spot.

In same vein, watch the "crow's foot" some places sell. The ones with loose terminal forks (that tighten when lug is tightened) are often labeled for EGC only, not neutrals. Easy to overlook if rushed or desperate.