Inspector and MWBC

[KnobnTube]

Contractor friend asked me if I had any input on the situation.
Inspector did not give Article but failed inspection until correction is done.
I have no idea.

There is a MWBC to separate receptacles.
Room with MWBC is merely a bonus room, so no particular need on amperage.
Older home getting a service upgrade.
The MWBC is question has one receptacle on a 15 amp and the other is 20 amp.
So, we have 15 and 20 amp breakers tied together with proper handle tie.
Neutral is #12, then the #14 and #12 on the breakers.
Inspector says "no", the #14 must be changed to #12 and both breakers must be 20 amp.

He did not leave any additional information as yet.

Thought would post and see if anyone had any ideas before he confronts the inspector, as we cannot find anything stating they must be the same, as long as the neutral is equal to the highest amperage breaker.

Ideas?

Thanks

 

[jumper]

Inspector cannot cite a code section, because inspector is incorrect IMO.

EGC for that circuit needs to be a #12 also.

While a mixed 15A and 20A MWBC may not be the norm, it is legal AFAIK.

 

[ActionDave]

A little wierd, maybe tacky; but not a violation that I know of.

 

[480sparky]

The inspector may say No, but must quote a Code section to support the alleged violation.... not a 'shirt-pocket rule'.

 

[kwired]

Usually only happens with raceway type wiring methods also, and I know I have done that many times before.

 

[480sparky]

Usually only happens with raceway type wiring methods also, and I know I have done that many times before.

I've seen it once with NM. 12/3 from 15 and 20a breakers, then the red was tied to a 14/2 downstream.

 

[kwired]

I've seen it once with NM. 12/3 from 15 and 20a breakers, then the red was tied to a 14/2 downstream.

I have also done that. With AFCI requirements it hardly happens anymore but outside of that I have no problem with it.

 

[david]

Contractor friend asked me if I had any input on the situation.
Inspector did not give Article but failed inspection until correction is done.
I have no idea.

There is a MWBC to separate receptacles.
Room with MWBC is merely a bonus room, so no particular need on amperage.
Older home getting a service upgrade.
The MWBC is question has one receptacle on a 15 amp and the other is 20 amp.
So, we have 15 and 20 amp breakers tied together with proper handle tie.
Neutral is #12, then the #14 and #12 on the breakers.
Inspector says "no", the #14 must be changed to #12 and both breakers must be 20 amp.

He did not leave any additional information as yet.

Thought would post and see if anyone had any ideas before he confronts the inspector, as we cannot find anything stating they must be the same, as long as the neutral is equal to the highest amperage breaker.

Ideas?

Thanks

What is the wiring method being used to make up the MWBC?

 

[roger]

I bet this would throw the inspector for a loop.

Roger

 

[kwired]

I bet this would throw the inspector for a loop.

Roger

Maybe would have me guessing also. It says common trip on the 100 amp side so it is a double pole breaker - maybe. Does anyone make a double pole that is different rating on each pole? Is that a 35, a 100, both, or even something else. Probably from the last batch on a Friday at the assembly plant? Or does Friday even matter in Mexico?

 

[Sierrasparky]

Looks like another code book out a thin air inspector.
guys like this need to flogged. I say that, in some areas when you challenge the inspector you wind up causing more trouble than its worth. That is not the way it should be.

 

[roger]

Maybe would have me guessing also. It says common trip on the 100 amp side so it is a double pole breaker - maybe. Does anyone make a double pole that is different rating on each pole? Is that a 35, a 100, both, or even something else. Probably from the last batch on a Friday at the assembly plant? Or does Friday even matter in Mexico?

It is a two pole breaker. It was in a panel we demoed on a job maybe 10 years ago. I have a feeling it was a Monday morning or a Friday afternoon assembly.

Roger

 

[LEO2854]

Looks like another code book out a thin air inspector.
guys like this need to flogged. I say that, in some areas when you challenge the inspector you wind up causing more trouble than its worth. That is not the way it should be.

You're right it should not,some of them are just testing your code knowledge and back off once they think you know the NEC.

And then there are the ones that need to go back out in the field and get up to speed on the real world :lol::slaphead:

 

[david]

Unless this is in conduit how do you do this type of MWBC in a dwelling when the MWBC portion of the circuit originates from the breakers in the panel? Or is this Knob and tube, asking because I never seen a multi wire branch circuit set up this way.

 

[480sparky]

Unless this is in conduit how do you do this type of MWBC in a dwelling when the MWBC portion of the circuit originates from the breakers in the panel? Or is this Knob and tube, asking because I never seen a multi wire branch circuit set up this way.

The wiring method (EMT, NM, MC, etc) is not relevant.

What IS relevant is the smallest conductor in the circuit is properly protected by the OCD.

 

[david]

The wiring method (EMT, NM, MC, etc) is not relevant.

What IS relevant is the smallest conductor in the circuit is properly protected by the OCD.

It may not be relevant to you but it is to me!
How would you do this with NM cable or MC cable I never seen 12/14/ w 12 G cable.

 

[iwire]

During a commercial office remodel I reused a 6/3 MC for a 20 and 30 amp 120 circuit.

There may have been 250.122(B) issues but it was not brought up at inspection.

 

[LEO2854]

It may not be relevant to you but it is to me!
How would you do this with NM cable or MC cable I never seen 12/14/ w 12 G cable.

I think you can have that made special order,but there goes all the savings.

 

[david]

1 was also thinking of 300.3(B)

 

[david]

I think you can have that made special order,but there goes all the savings.

yes but the OP said it was a service upgrade inspection