Individual branch circuit

[paulyoung]

Here's what we have going on,
I have a piece of equipment that states on the label that it needs an individual branch circuit. The debate that we're having is if that equipment can be on a multi-wire branch circuit or if it must be on a circuit that doesn't share a neutral.

 

[MAC702]

This is common. A dishwasher and a garbage disposal are on individual branch circuits. To make it easy, we use a MWBC, since it goes to the same place. Same thing is common with a washer and gas dryer on individual branch circuits on a common yoke with a MWBC. I don't know what is currently common with the invasion of bribery and AFCIs, and I don't care. Not relevant anyway.

 

[oldsparky52]

Here's what we have going on,
I have a piece of equipment that states on the label that it needs an individual branch circuit. The debate that we're having is if that equipment can be on a multi-wire branch circuit or if it must be on a circuit that doesn't share a neutral.

Since the equipment is requiring this, maybe a phone call to the manufacturer (maybe better an email for trace-ability) for clarification. If you feed it with a MWBC, and there is operational difficulties that are not easily solved, it may get pushed to a wiring issue. If it isn't that big of a deal, I would install the circuit with a dedicated neutral for that individual branch circuit.

What is this equipment?

 

[paulyoung]

Since the equipment is requiring this, maybe a phone call to the manufacturer (maybe better an email for trace-ability) for clarification. If you feed it with a MWBC, and there is operational difficulties that are not easily solved, it may get pushed to a wiring issue. If it isn't that big of a deal, I would install the circuit with a dedicated neutral for that individual branch circuit.

What is this equipment?

It is a central vacuum unit.
I was thinking the same thing about contacting the manufacturer.
The problem we're running into is at rough we don't know what brand they are installing and not all brands are labeled this way. Which makes me think that their intention is that it be a circuit by itself, (dedicated for lack of a better term), which a multi-wire would comply with.

 

[LarryFine]

Paul, I agree with your reasoning.

 

[infinity]

I see no reason to not use a MWBC if it suits your needs. As MAC stated a MWBC can be an individual branch circuit(s) by NEC definition.

 

[paulyoung]

I see no reason to not use a MWBC if it suits your needs. As MAC stated a MWBC can be an individual branch circuit(s) by NEC definition.

That is where we are having the disagreement!
I also think that a MWBC can be an individual branch circuit but I seem to be in the minority, not alone but in the minority.

I have dispatched an e-mail to the manufacturer and will let you know their response.

 

[oldsparky52]

It is a central vacuum unit.

I would not be concerned about using a MWBC. But, will it require an AFCI? Would that be an issue?

 

[paulyoung]

I would not be concerned about using a MWBC. But, will it require an AFCI? Would that be an issue?

I am in Idaho. AFCI is only required in bedrooms. However the units are usually located in the garage so they do have to have GFCI protection.

 

[oldsparky52]

I am in Idaho. AFCI is only required in bedrooms. However the units are usually located in the garage so they do have to have GFCI protection.

So you can do that (GFCI) at the equipment with a receptacle instead of at the panel (if it AFCI was required). So a MWBC should be no problem.

I am curious, what's the cost savings by running a MWBC? What else would share the MWBC (the other circuit)?

 

[paulyoung]

So you can do that (GFCI) at the equipment with a receptacle instead of at the panel (if it AFCI was required). So a MWBC should be no problem.

I am curious, what's the cost savings by running a MWBC? What else would share the MWBC (the other circuit)?

Generally, it is usually a freezer, but it could be a water softener etc

 

[MAC702]

On the plus side, sounds like everything might be close to the panel anyway? Around here the panel is almost always on a garage wall.

 

[LarryFine]

I say that a multi-wire branch circuit can supply multiple individual branch circuits.

Sharing a neutral does not preclude a circuit from being an individual branch circuit.

 

[synchro]

I suspect that the equipment's requirement for an individual branch circuit just reflects a need to have an adequate source of power that's not subject to being overloaded by other equipment. So a MWBC does not have any issue in meeting that need.

However, it probably would not be wise to have loads on the other MWBC conductors which are sensitive to conducted noise like audio, entertainment, telecom, and similar functions. This is because many, if not most, central vacs have brushed motors that create a significant amount of interference on their load current that would produce a noise voltage on the shared neutral conductor of a MWBC. The freezer and water softener mentioned and similar loads should not present any problem.

 

[paulyoung]

It is a central vacuum unit.
I was thinking the same thing about contacting the manufacturer.
The problem we're running into is at rough we don't know what brand they are installing and not all brands are labeled this way. Which makes me think that their intention is that it be a circuit by itself, (dedicated for lack of a better term), which a multi-wire would comply with.

Just to update here is the response that I received from the manufacturer.

"They do suggest yes that is is on its on circuit or it may case the unit to continually shut down or trip the breaker , I have seen this be a problem in the past when people do not put it on a dedicated line." H-P Products Customer Service

So the response was pretty much what was expected, Basically just want it on a circuit by itself.