Adding circuits in existing boxes


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Old 07-15-09, 10:44 AM
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Adding circuits in existing boxes

I have added a couple of 20amp circuits to my house to accomodate some new kitchen lighting. I am replacing some single gang boxes and replacing them with deep double gang boxes to accomodate the new switches. The existing lights will be on the existing circuits.

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Is it OK to mix circuits in one box? (They are all 20 amp)
Do I tie all the grounds together or seperatley for each circuit or does it really matter?
Thanks!
JP
 
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Old 07-15-09, 10:54 AM
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Is it OK to mix circuits in one box? (They are all 20 amp)
Do I tie all the grounds together or seperatley for each circuit or does it really matter?
Thanks!
Multiple circuits in one box is ok. All grounds must be tied together and pigtailed to box if metal. Neutrals must be isolated within their individual circuits.
 
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Old 07-15-09, 11:58 AM
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Originally Posted by politronics
I have added a couple of 20amp circuits to my house to accomodate some new kitchen lighting. I am replacing some single gang boxes and replacing them with deep double gang boxes to accomodate the new switches. The existing lights will be on the existing circuits.

Quesions:

Is it OK to mix circuits in one box? (They are all 20 amp)
Do I tie all the grounds together or seperatley for each circuit or does it really matter?
Thanks!
JP
Yes, it's OK to mix circuits in the boxes. I do keep my grounds with each circuit and don't tie them all together. This will make it easier if you are trouble shooting a problem. As ray quoted if they are steel boxes you must tie your grounds to the steel box also. Neutrals must also stay with their own circuit also. Hope this helps and be safe.
Jim
 
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Old 07-15-09, 07:59 PM
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Originally Posted by rukkus11
Yes, it's OK to mix circuits in the boxes. I do keep my grounds with each circuit and don't tie them all together. This will make it easier if you are trouble shooting a problem. As ray quoted if they are steel boxes you must tie your grounds to the steel box also. Neutrals must also stay with their own circuit also. Hope this helps and be safe.
Jim
Grounds from different circuits in the same box need to be connected together.
 
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Old 07-16-09, 01:03 PM
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Originally Posted by pcboss
Grounds from different circuits in the same box need to be connected together.
I don't think it's required, but it's not prohibited either. pcboss: If I'm wrong could you give my some direction in the NEC book so I can learn more about this.
Thanks!
Jim
 
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Old 07-16-09, 01:11 PM
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250.148 is probably most relevant.
 
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Old 07-16-09, 02:57 PM
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Talking

Originally Posted by ibpooks
250.148 is probably most relevant.
ibpooks, Thanks for that information. I did read it but only talking about circuit conductors and not 2 different circuits. What I thought it was talking about is if you had a circuit ran to a box and your had other wires in the same box that fed to other locations then you tie all the wires together. I didn't read anything about if you had 2 different circuits running to a box. It's hard for me to understand the wording of this book sometime. Just trying to learn!
Thank you!
Jim
 
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Old 07-16-09, 08:38 PM
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I don't have a code book handy so I don't have a direct quote, but I believe the language is something like, "any equipment grounding conductor in the box must be spliced with an approved connector and also connected to the box." The part about splicing other conductors means that you only need to connect the grounds together if other conductors are also spliced, meaning that if the box is used only a pull point in a conduit system then you do not need to splice the grounds, but any other boxes must have the grounds spliced.
 
 

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