300.13 b

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am I right in thinking that a device cannot be used as a splicing means? That is to say that you can't use a receptacle as a wire nut. If you can't, why do they put all the terminals on an outlet? Help me understand what 300.13 b is saying. I always thought that your not suppose to use the outlet as a wire nut.
 

celtic

Senior Member
Location
NJ
monkey_man_100 said:
please help me understand the code
This is a prime example of where the NECH comes in handy.

Below is the commentary following 300.13(B):
Grounded conductors (neutrals) of multiwire branch circuits supplying receptacles, lampholders, or other such devices are not permitted to depend on terminal connections for continuity between devices. For such installations (3- or 4-wire circuits), a splice is made and a jumper is connected to the terminal, unless the neutral is looped; that is, a receptacle or lampholder could be replaced without interrupting the continuity of energized downstream line-to-neutral loads (see commentary to 300.14). Opening the neutral could cause unbalanced voltages, and a considerably higher voltage would be impressed on one part of a multiwire branch circuit, especially if the downstream line-to-neutral loads were appreciably unbalanced. This requirement does not apply to individual 2-wire circuits or other circuits that do not contain a grounded (neutral) conductor.
 

drg

Senior Member
You guys are correct but if the op has never worked with a multi-wire branch circuit this is hard to understand, guess I can speak for myself because until I actually worked with "networks or fullboats" understanding this was kind of hard for me to relate to theory wise, guess some of us just need to see it, and work on it, and then we understand .
 

iwire

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Location
Massachusetts
drg said:
You guys are correct but if the op has never worked with a multi-wire branch circuit this is hard to understand,
We don't have to understand MWBCs to see that 300.13(B) only applies to the grounded conductor of a MWBC.:smile:

If the poster had asked why 300.13(B) exists than we would need to understand MWBCs.
 

George Stolz

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Monkey, one aspect of this that may be unclear is what a multiwire branch circuit is.

From Article 100, Definitions:
Branch Circuit, Multiwire. A branch circuit that consists of two or more ungrounded conductors that have a voltage between them, and a grounded conductor that has equal voltage between it and each ungrounded conductor of the circuit and that is connected to the neutral or grounded conductor of the system.
So, in a house, a 14/3 home-run from the panel to a receptacle is a multiwire branch circuit. If the conductors are landed properly, then there will be

  • 240V measured from black to red
  • 120V measured from black to white
    [*]120V measured from red to white

For this type of circuit, if the neutral is lost (due to a bad connection at a receptacle) then the voltage each leg sees will not be 120V - the voltage to neutral will change, depending on the resistance of the loads connected to the circuit.
 
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drg

Senior Member
monkey_man_100 said:
Help me understand what 300.13 b is saying.
From Bob
If the poster had asked why 300.13(B) exists than we would need to understand MWBCs.

Bob , in a round about way it sounds like he is asking exactly that much.
 

celtic

Senior Member
Location
NJ
drivetr. said:
What does NECH stand for? Thanks
Sorry.

The NEC is, obviously, the National Electrical Code ~ aka "The Bible"

The NECH is the National Electrical Code Handbook ~ aka" The Bible with pictures".
 

ibew441dc

Senior Member
In my understanding a receptacle is not intended as a splicing device.

Though it is true that many are listed for feed thru, they are not splicing devices like wirenuts.

Like others had mentioned, the major concern of 300.13(B) is in regards to continuity of the grounded conductor in a MWBC.

I would review 110.14(A) and (B) in regards to terminals and splices.




IBEW441DC
 

George Stolz

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Location
Windsor, CO NEC: 2017
Occupation
Service Manager
ibew441dc said:
In my understanding a receptacle is not intended as a splicing device.

Though it is true that many are listed for feed thru, they are not splicing devices like wirenuts.
Could you explain that more clearly? It seems like you're saying two different things.

I don't believe anyone was using a device like a wirenut in the purest sense, as in, connecting the conductors and then wadding it into the back of the box. ;)
 

don_resqcapt19

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Location
Illinois
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retired electrician
The following is from UL Guide RTRT for recptacles.
Single and duplex receptacles rated 15 and 20 A that are provided with more than one set of terminals for the connection of line and neutral conductors have been investigated to feed branch circuit conductors connected to other outlets on a multi-outlet branch circuit, as follows:
  • Back wire (screw actuated clamp type) terminations with multiple wire access holes used concurrently to terminate more than one conductor
  • Side wire (binding screw) terminals used concurrently with their respective push-in (screwless) terminations to terminate more than one conductor
Single and duplex receptacles rated 15 and 20 A that are provided with more than one set of terminals for the connection of line and neutral conductors have not been investigated to feed branch circuit conductors connected to other outlets on a multi-outlet branch circuit, as follows:
  • Side wire (binding screw) terminal with its associated back wire (screw actuated clamp type) terminal
  • Multiple conductors under a single binding screw
  • Multiple conductors in a single back wire hole
Don
 

ibew441dc

Senior Member
monkey_man_100 said:
am I right in thinking that a device cannot be used as a splicing means? That is to say that you can't use a receptacle as a wire nut. If you can't, why do they put all the terminals on an outlet? Help me understand what 300.13 b is saying. I always thought that your not suppose to use the outlet as a wire nut.

GEORGESTOLZ


I was mearly responding to monkeymans comment about using a receptacle as a wirenut.
My point was that receptacles are not intended to be used as splicing devices in the same manner as wirenuts.
 
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