# Grounded  Conductors  On  Panel  Board  Terminals



## north star (Jun 18, 2010)

** * **

*I am having a discussion with an electrical contractor, regarding the number of conductors*

*that can be installed in / under each setscrew [ in the panel boards ].*

*He says that more than one can be installed, as long as that particular panel board*

*manufacturer allows it. I am saying / thinking that Article 408.41 [ in the `08 NEC ]*

*limits the total number of conductors to just one. The Exception to Article 404.81 seems*

*to allow more than one grounded conductor under the setscrew, but the conductor cannot*

*be damaged or overtightened [ refer to Article 110.3(B) & 110.14 ]*

*I seem to recall us having a discussion about this very topic recently on here...*

*Your input is requested!* 



** * **


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## peach (Jun 18, 2010)

408.41 allows one and one only. The exception is for parallel conductors which per 310.4 would be 1/0 min 

thanks Greg


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## north star (Jun 21, 2010)

**    *    ** 

*Thank you peach [ and Greg ]!*



**    *    **


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## Iowa49 (Jun 21, 2010)

Some panel manufacturers do allow more than one, usually up to three of the same size, grounding conductors in the same terminal.  Only one grounded conductor is allowed to terminate in each terminal.


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## north star (Jun 21, 2010)

** * ** 

*Iowa49,*

*I am unclear as to what you are stating. Can you please clarify?*

*Thanks! * 



** * **


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## fatboy (Jun 21, 2010)

*Equipment* Grounding Conductors, multiple OK (based on Man.) vs. Grounded conductors, one allowed.


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## 480sparky (Jun 21, 2010)

_*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._

Pretty much says one neutral per terminal.


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## EPrice (Jun 21, 2010)

Lets make sure we are all clear on the terminology here.

_Grounded conductor_, commonly referred to as the neutral: One allowed per screw per 408.41 as referenced by peach and 480sparky.

_Grounding conductor_, or equipment ground (bare or green conductor): One or more conductors per screw as allowed by the equipment manufacturer.  The limiting factor here is the conditions of listing of the terminals.


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## north star (Jun 21, 2010)

** * **

*Thank you all for your input! * 

*In this one particular application, the Elec. Contractor has two neutrals under one*

*set screw [ on one side of the panel board ], and two bare conductors under each*

*set screw [ on the other side of the panel board ]. His reasoning is **' the*

*manufacturer allows it '**. Is this a true statement? Can he install multiples?*

*a)** What about isolating that particular branch circuit when more than one neutral*

*is connected to the same terminal? **b)** Is this a correct install - - one neutral*

*only, per 408.41, but more than one, but no more than three **"equipment grounding*

*conductors"** are allowed per 408.41, **or**  more than one neutral, per the*

*manufacturer of the panelboard and more than one "equipment grounding*

*conductor"? *

** * **


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## 480sparky (Jun 21, 2010)

Let him produce the documentation from the manufacturer that 'allows it' if he wants to get it past the inspector.

I think 408.41 is pretty plain..... when terminating a grounded conductor, it will be by itself.


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## north star (Jun 21, 2010)

** * **

*Agreed 480 sparky!*

*Is this a common allowance by [ some ] panel board manufacturers?*

*I see a lot of it `round these parts.  *

** * **


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## 480sparky (Jun 21, 2010)

I've never known a panel to allow it.  At least on the grounded (neutral) conductors.

Some makers allow two ungrounded (hots) on the breaker, but that's a different story.


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## raider1 (Jun 21, 2010)

480sparky said:
			
		

> I've never known a panel to allow it.  At least on the grounded (neutral) conductors.Some makers allow two ungrounded (hots) on the breaker, but that's a different story.


I agree, I have never seen a modern panelboard that has installation instructions that permit multiple grounded conductors to be installed under 1 screw.

Chris


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## peach (Jun 27, 2010)

well, that.. and why would you want to?  If there are that many circuits, you need to re-think what you are doing.  Just saw one this week... lots of open screws.. no reason.  Lazy electrician?


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