One (1) duplex receptacle for disposal and dish washer?

[hurk27]

I think you've got this all wrong.

The definition of a MWBC clearly states it is a single circuit.

The definition of receptacle makes it clear that if a yoke features two devices, then it is a multiple receptacle.

Where are you coming up with two circuits with single receptacles?

A duplex with a disposal on phase A and a dishwasher on phase B is clearly not an individual branch circuit; 210.21(B)(1) does not apply.

So then I guess we don't need to follow 210.7(B) when we use a MWBC to a duplex:?

(B) Multiple Branch Circuits. Where two or more branch
circuits supply devices or equipment on the same yoke, a
means to simultaneously disconnect the ungrounded conductors
supplying those devices shall be provided at the
point at which the branch circuits originate

 

[iwire]

So then I guess we don't need to follow 210.7(B) when we use a MWBC to a duplex:?

We don't.

But we do have to follow 210.4(B).

 

[George Stolz]

Not at all. 210.4(B) does that job nicely. Look back a few cycles, do you see?

 

[George Stolz]

Jinx!

 

[iwire]

It is semantics, IMO. The definition does not state it is a single circuit-- where does it say that? Show me the words in the definition that calls it a single circuit.

The "A" makes it so IMO. 'A' is singular is it not?

I already answered that. In the case of a range it is a single circuit.

My bad, sorry.

As Roger stated 210.4 says that a mwbc shall be permitted to be considered as multiple circuits. Yet you say it is a single circuit. Okay--

Exactly, 'shall be permitted to be considered as multiple circuits' IMO that tells us that the NEC considers it a single circuit that in some applications can be considered two circuits. It is not saying that it is two circuits.

I really don't want to argue this any further.

Well I guess we should turn the server off and go home. hmy:

 

[david]

The "A" makes it so IMO. 'A' is singular is it not?



My bad, sorry.



Exactly, 'shall be permitted to be considered as multiple circuits' IMO that tells us that the NEC considers it a single circuit that in some applications can be considered two circuits. It is not saying that it is two circuits.



Well I guess we should turn the server off and go home. hmy:

How does 210.23 enter into your discussion on weather it is a single branch circuit or two branch circuits. Feeding a dishwasher and a say a ? HP disposal

 

[George Stolz]

How does 210.23 enter into your discussion on weather it is a single branch circuit or two branch circuits. Feeding a dishwasher and a say a ? HP disposal

It's a 20A 240V circuit. The circuit is not overloaded, so 210.23 is satisfied.

 

[John120/240]

For a dishwasher & disposal, I would install one 20 amp circuit. 12 3 from the switch to the

Receptacle. Break the tab on the hot side, constant hot for DW, switched half for disposal.

This arrangement does not constitute a MWBC. Everybody already know this tho.

 

[david]

What about a kitchen if one 20 amp Mutiwire circuit supplied all the counter top rec. in a kitchen. Or for that matter all of the rec. in a kitchen. Is it one circuit or two? Are you guys saying it?s a code violation to serve the kitchen rec. with one 20 amp multiwire circuit?

 

[George Stolz]

As Roger stated 210.4 says that a mwbc shall be permitted to be considered as multiple circuits.

Bob said this, but let me reiterate; it says that a MWBC shall be permitted to be considered multiple circuits. This is not the same as saying, "A MWBC shall be considered multiple circuits."

One is voluntary, the other is not. When it is convenient for us to call it "multiple circuits" such as to comply with 210.52(B)(1), then we are permitted to consider it multiple circuits for our ends. Otherwise, it is a single circuit.

In this case, it is a single circuit with a duplex receptacle on it serving two loads.

 

[david]

For a dishwasher & disposal, I would install one 20 amp circuit. 12 3 from the switch to the

Receptacle. Break the tab on the hot side, constant hot for DW, switched half for disposal.

This arrangement does not constitute a MWBC. Everybody already know this tho.

Then it clearly is not one branch circuit but two under those conditions correct?

 

[George Stolz]

What about a kitchen if one 20 amp Mutiwire circuit supplied all the counter top rec. in a kitchen. Or for that matter all of the rec. in a kitchen. Is it one circuit or two? Are you guys saying it?s a code violation to serve the kitchen rec. with one 20 amp multiwire circuit?

Absolutely not, that's what 210.4(A) is permitting us to do that the definition otherwise would prohibit. Did you watch the excerpt from Mike's video that I posted above?

 

[George Stolz]

Then it clearly is not one branch circuit but two under those conditions correct?

He's confusing the issue - he is saying he pulls a 12-2 home run to a switch (single 120V circuit) and then routes a 12-3 switchleg down to the receptacle. That's different.

 

[david]

Bob said this, but let me reiterate; it says that a MWBC shall be permitted to be considered multiple circuits. This is not the same as saying, "A MWBC shall be considered multiple circuits."

One is voluntary, the other is not. When it is convenient for us to call it "multiple circuits" such as to comply with 210.52(B)(1), then we are permitted to consider it multiple circuits for our ends. Otherwise, it is a single circuit.

In this case, it is a single circuit with a duplex receptacle on it serving two loads.

Ok what if I add the kitchen lights too this single circuit do I consider both the dish washer an the disposal added together to determine if my equipment exceeds 50% of the 20 amp rating of this single branch circuit? Or am I missing something here.

 

[George Stolz]

Ok what if I add the kitchen lights two this single circuit do I consider both the dish washer an the disposal added together to determine if my equipment exceeds 50% of the 20 amp rating of this single branch circuit? Or am I missing something here.

There's no magic to it. If your dishwasher pulled 5A, then you are at less than 50% for the fixed appliances of that portion of the circuit, that leaves you 15A worth of lighting to add if you desire.

 

[ActionDave]

The definition of a MWBC clearly states it is a single circuit.

The definition of receptacle makes it clear that if a yoke features two devices, then it is a multiple receptacle.

Where are you coming up with two circuits with single receptacles?

A duplex with a disposal on phase A and a dishwasher on phase B is clearly not an individual branch circuit; 210.21(B)(1) does not apply.

Well stated and I agree. Two places to plug something in equals multiple.

The "du" in duplex is derived from the French word "duex", meaning two.

 

[George Stolz]

Well stated and I agree.

(And no conspiracy this time. :lol: )

 

[david]

There's no magic to it. If your dishwasher pulled 5A, then you are at less than 50% for the fixed appliances of that portion of the circuit, that leaves you 15A worth of lighting to add if you desire.

I read 210.21(A) (2) to say the total rating of utilization equipment if it’s a single branch circuit would I not have to add the 5 amp dishwasher to plus the amps for the ? HP disposal?

In other words what would be the difference in applying 210.21(A) to a single pole 12/2 Branch circuit verses a 2 pole 12/3 branch cercuit

 

[George Stolz]

I read 210.21(A) (2) to say the total rating of utilization equipment if it?s a single branch circuit would I not have to add the 5 amp dishwasher to plus the amps for the ? HP disposal?

I suppose you could read it that way - if you add the two poles of the breaker that say 20 together to equal 40 - you'll get the same results.

You could look at it any number of ways. Since the rated load of the dishwasher is 5A @ 120V then you could simply figure the load for a 240V circuit, 2.5A.

 

[david]

I suppose you could read it that way - if you add the two poles of the breaker that say 20 together to equal 40 - you'll get the same results.

You could look at it any number of ways. Since the rated load of the dishwasher is 5A @ 120V then you could simply figure the load for a 240V circuit, 2.5A.

I thought the rating of the branch circuit would be determined by the 20 amp Over- current protection.