Tandem Breaker Tie Bar

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KevFla2001

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Hi
My question is about my installation of a tandem 20 amp breaker (panel accepts them), using 12 gauge wire (1 black, 1 red, 2 neutral, 1 ground) through 1/2 inch emt to a double pole switch in 4 inch square surface mount metal box, then a 3 inch run of 1/2 emt to a 4 inch square surface mount metal box containing two 20 amp duplex receptacles. Total emt run is less than 10 feet from panel to receptacles. Each receptacle has it's own 120 v circuit and both are controlled by the double pole switch.

It's not a multiwire circuit so no tie bar is required, but I'm thinking I should put one on anyway for safety sake in case one receptacle faults but the other in the same box stays hot, thereby being a danger to work on if not caught at the panel by a knowledgeable person.
Is there any problem with putting a tie bar across both handles on the tandem breaker? Is there any issues that I'm not aware of with this installation?
Thanks
Kevin
 
If you have two circuits on one yoke (the 2 pole switch) you still need to handle-tie the two single poles together or use a 2 pole circuit breaker.

Welcome to the Forum. :)
 
Using a double pole switch for two circuits is a violation unless the switch is labeled for two circuits and it won't be.

You can make it a multiwire branch which is one circuit so the double pole switch will be OK
 
In the case of the switch feeding two separate receptacles I see this as 2 circuits even if you use a MWBC.
 
iwire said:
No, if you think like that a MWBC would always be more than one circuit.

By NEC defintion it is one circuit.
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Well have to disagree, it doesn't say that's it's one circuit it says it can be considered one circuit as in 225.30. A single 3-wire MWBC to the kitchen counter satisfies the requirement for two circuits feeding the counter top receptacles. :)
 
infinity said:
Well have to disagree, it doesn't say that's it's one circuit it says it can be considered one circuit as in 225.30. A single 3-wire MWBC to the kitchen counter satisfies the requirement for two circuits feeding the counter top receptacles. :)
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I know about 225.30. Those words would not be there if a MWBC was not one circuit.

I am not going to agree to disagree here, in my opinion you are mistaken.
 
Back before 210.4(B) we all ran them off individual breakers so I think of them as individual circuits.

Code says otherwise though. Article 100 says "A branch circuit....." 210.4(A) says "A multiwire circuit shall be permitted to be considered as multiple circuits".
 
210.4 Multiwire Branch Circuits.

(A) General. Branch circuits recognized by this article shall be permitted as multiwire circuits. A multiwire circuit shall be permitted to be considered as multiple circuits. All conductors of a multiwire branch circuit shall originate from the same panelboard or similar distribution equip-ment.
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It does not change the fact I can use a MWBC with a double pole switch that is for single circuit use.
 
ActionDave said:
Back before 210.4(B) we all ran them off individual breakers so I think of them as individual circuits.

Code says otherwise though. Article 100 says "A branch circuit....." 210.4(A) says "A multiwire circuit shall be permitted to be considered as multiple circuits".
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The question thus transmogrifies into, can we consider an MWBC as one circuit and multiple circuits simultaneously? :angel:
 
I'm curious as to wether this is a tandem breaker like a twin 20/20, or 2 single poles? If it's a tandem 20/20 you can't run the circuit anyways. You have one neutral for two hots on the same phase correct?
 
Smart $ said:
The question thus transmogrifies into, can we consider an MWBC as one circuit and multiple circuits simultaneously? :angel:
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The real question is, as Bob initially mentioned, what does the listing of the 2-pole switch say.
 
This breaker is a Siemens 20 Amp Tandem Single-Pole Type QT Circuit Breaker with 2 separate circuits and 2 separate trip handles, and again, it uses only 1 phase. The entire panel is made up of tandem breakers and also has 2 quad breakers installed when the house was built 14 years ago.

I pulled the 2014 code book and I do see where they deleted the multi circuit multi pole switch section that used to say " if the voltage rating of the switch is not less than the line to line voltage of the system supplying the circuits" which would have allowed it's use. I could have used the MWBC wiring but I didn't want the remote possibility of a bad or broken shared neutral. The switch is for convenience only as I could switch the breaker off when my equipment is not in use, but I would love to have it switched where I can see if it's on or off as it is now.

I searched for 2 circuit double pole switches and didn't come up with anything. Does anyone know where to find one and approximately how much they cost?

Thanks,
Kevin
 
I just got off the phone with Leviton technical support and the technician has never heard of a 2 circuit rating on a double pole switch and I can't find anything online referring this either.

These 2 circuits will only power these 4 bench tools: drill press, grinder, sander and chop saw, none will be on at the same time and none will be running when using the double pole switch thereby preventing any type of arc in the switch.

This switch works fine but I do want to follow code and if I can replace it with a "2 circuit rated" double pole switch I will. Any help on this will be GREATLY appreciated.

Thanks,
Kevin
 
As I stated earlier then, this is not a mwbc. You have the capabilities to pull 2-120v ckts but you will need to pull them in seperate cable runs. You cannot share the neutral between the two.
 
KevFla2001 said:
I just got off the phone with Leviton technical support and the technician has never heard of a 2 circuit rating on a double pole switch and I can't find anything online referring this either.

These 2 circuits will only power these 4 bench tools: drill press, grinder, sander and chop saw, none will be on at the same time and none will be running when using the double pole switch thereby preventing any type of arc in the switch.

This switch works fine but I do want to follow code and if I can replace it with a "2 circuit rated" double pole switch I will. Any help on this will be GREATLY appreciated.

Thanks,
Kevin
Click to expand...

Two issues, since you have two circuits connected to one yoke (the switch) you will need a 2 pole CB or a handle tie on two single pole CB's. The next question is can a 2 pole switch be used in this application (the way you have it wired with separate neutrals) and the answer is no.
 
Going back to the one or two circuit question, if a two-pole, two-circuit switch cannot be had and a MWBC can be counted as one circuit through a two-pole switch, replace a couple tandems with a handle-tied quad, and run the "two" circuits as a MWBC.

Then there's always the true two-circuit switch (three-ways pictured but not required).
 

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Smart $ said:
Going back to the one or two circuit question, if a two-pole, two-circuit switch cannot be had and a MWBC can be counted as one circuit through a two-pole switch, replace a couple tandems with a handle-tied quad, and run the "two" circuits as a MWBC.

View attachment 16340
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That may work but I would opt for plan B, two cheap single pole switches. :D
 
infinity said:
That may work but I would opt for plan B, two cheap single pole switches. :D
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I was trying to make a new post to this effect before you posted, but I inadvertently edited my existing post out of existence. Fortunately, I recovered my original post from your reply and just modified it. :D
 
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