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A panel has 2 single pole 20amp breakers for the kitchen with a shared neutral. The house has been there for years so I'm assuming this was done awhile ago. I'm trying to understand how this is ok on the neutral as it makes me nervous due to reading about how multiwire branch circuits should be tied via a handle tie or 2 pole breaker, which they are not.

Any wisdom on this would be appreciated. Thank you
 

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36th year apprentice & Floor Sweeper
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It’s fine the way it is. If the electrician spliced the neutral through, and doesn’t rely on the device for continuity, it’s all good. Any qualified mechanic should know to shut off all the breakers of a multiwire branch circuit before opening the neutral splice.

<Rant>
Handle ties put one more nail in the coffin of the conduit trade. Most job specs don’t allow handle ties or multi-pole breakers on branch circuits. This eliminates shared neutrals and increases conduit fill and wire size due to derating. Just yank homerun MC to compensate.
 

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A panel has 2 single pole 20amp breakers for the kitchen with a shared neutral. The house has been there for years so I'm assuming this was done awhile ago. I'm trying to understand how this is ok on the neutral as it makes me nervous due to reading about how multiwire branch circuits should be tied via a handle tie or 2 pole breaker, which they are not.

Any wisdom on this would be appreciated. Thank you
There are millions of multiwire branch circuits sharing neutrals in use today, with each circuit on an Edison plug fuse or on breakers not handle tied together. It was until recently perfectly legal and safe.
 

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There are millions of multiwire branch circuits sharing neutrals in use today, with each circuit on an Edison plug fuse or on breakers not handle tied together. It was until recently perfectly legal and safe.
Just remember, last year’s safe compliant install is this year’s ticking time bomb. ;)
 

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A panel has 2 single pole 20amp breakers for the kitchen with a shared neutral. The house has been there for years so I'm assuming this was done awhile ago. I'm trying to understand how this is ok on the neutral as it makes me nervous due to reading about how multiwire branch circuits should be tied via a handle tie or 2 pole breaker, which they are not.

Any wisdom on this would be appreciated. Thank you
Theory wise it is the same as incoming power and neutral, current is vectorially added so it can't exceed the current on a single phase ( excluding harmonics).
Safety wise with all wire tight and not working on circuit it is safe.
The issue is feedback when working on it if you open one breaker or open the neutral.
Other issue is if you open neutral while both circuits are hot you will get unstable voltage from 0-240 volts depending on loads connected. This will let the smoke out of 120 volt devices.

Cowboy
 

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Just remember, last year’s safe compliant install is this year’s ticking time bomb. ;)
Will be replacing a friend's panel in a week. Guess how many Arc-faults I'm installing in their 3 bedroom 1968 ranch?
 

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Will be replacing a friend's panel in a week. Guess how many Arc-faults I'm installing in their 3 bedroom 1968 ranch?
All of them, as you bow in obeisance to your governmental overlords.
 

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Electrical contractor 37 years. Electrical inspector 2 years
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As for the notorious multiwire branch circuits what would you do? I went on a service call for a window AC unit tripping out the circuit breaker. When I took off the cover I noticed several multiwire circuits on twin breakers. The same twin breaker had both the black and red wire. It has been like that for over 20 years and the home owner is elderly and did not understand the problem. The white wire on one of them was brown. The choices were 1. Leave it alone and just fix what I was called for. 2. Put both black and red wires under the same breaker. 3. Keep the black on one leg and move the red to the other. There is no way for me to know where the other ends of the circuits are and there is a concern of sending 240 some where. I haven't used multiwire circuits for over 20 years because of the confusion it might cause down the road.
 

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I nominate this for post of the month!

Can I use it or is it copyright?
As a pirate molded in the form of the late PeterD/MTW I believe in open source materials. You are free to use it whenever you feel it’s appropriate.

Please remember PeterD with kind thoughts. We miss you User4818.
 

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Will be replacing a friend's panel in a week. Guess how many Arc-faults I'm installing in their 3 bedroom 1968 ranch?
0? Why are you installing AFCI on a panel change unless you are relocating the panel and extending the circuits?
 

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Good point, damn and I thought I was a rebel...
I got scared there for a bit. I thought I missed something. They keep on adding or changing the codes and sometimes I do not know which one we are on.
 

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I got scared there for a bit. I thought I missed something. They keep on adding or changing the codes and sometimes I do not know which one we are on.
Well it sure as hell doesn't help that we're not all on the same page now does it? I mean, someone asks a code question in 2021 and is like "We're on the 2015 but our unique amendments are still 2009..." Not to mention that some here claim if they touch anything in an older house their inspectors make them update totally unrelated things, and for sure some here believe that a panel change requires the arc-fault updates which I kinda knew didn't but in some jurisdictions they make you do it anyway.
 

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A panel has 2 single pole 20amp breakers for the kitchen with a shared neutral. The house has been there for years so I'm assuming this was done awhile ago. I'm trying to understand how this is ok on the neutral as it makes me nervous due to reading about how multiwire branch circuits should be tied via a handle tie or 2 pole breaker, which they are not.

Any wisdom on this would be appreciated. Thank you

If the conductors are on different phase- usually next to each other- then the neutral will never seen more than 20 amps. The formula is N = Line 1- Line 2

put 20 amps on both hot conductors and the neutral will read 0-- strange but true.

Put 20 amps on 1 and 0 on the other and the neutral will see 20 amps. As you can see you will never see more than 20 amps. If both hot conductors were on the same phase then the Neutral current would be added. 20 amps on both then the Neutral would see 40 amps.... That's would be the problem
 

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If the conductors are on different phase- usually next to each other- then the neutral will never seen more than 20 amps. The formula is N = Line 1- Line 2

put 20 amps on both hot conductors and the neutral will read 0-- strange but true.

Put 20 amps on 1 and 0 on the other and the neutral will see 20 amps. As you can see you will never see more than 20 amps. If both hot conductors were on the same phase then the Neutral current would be added. 20 amps on both then the Neutral would see 40 amps.... That's would be the problem
Don't you find it odd you have to explain that to a journeyman electrician?
 
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