Multi-wire Branch Circuit (Line-Line and Line-Neutral Loads)

[Exmark]

Hi everyone,

I am a long time reader of this forum, and I am excited to make my first post. Thank you in advance for any insight you can give me .

Today I ran into a situation that I do not know the answer to 100% and my efforts to find the answer (with absolute certainty) were in vain! I know this is the right place to find the answer, hence my first post.

We are under the 2008 code cycle. This pertains to an individual dwelling unit. The circuits in question are feeding pool equipment (pump, service outlet, and lighting). The dwelling unit has a 120v/240v single phase service. If I missed any relevant background information let me know, its been a fairly long day.

Can a 2 pole 20 amp GFCI breaker feed a 230v pool pump 1.5 HP, a 120v lighting load (small load, don't know specifics off-hand), and a service outlet using a Multi-wire branch circuit (2 hots, neutral, and ground)? This is the part I keep going back and forth on. Can a multi-wire branch circuit feed 120v and 240v loads at the same time according to the NEC? My gut tells me no, but I can't find a specific reason. Please settle my mind so that I can sleep!

I have not visited the jobsite yet, so lets make a few assumptions. 12-3 NM running inside the building, changed over to THHN/THWN before leaving the building. Lets assume proper bonding and pipework outside the building also, just to keep things on subject.

Thank you again in advance!

Exmark

 

[Dennis Alwon]

When you bring in pool pump and light there may be an issue-- is the light in the Pool????

If not this may answer your question

210.23(A)(2) Utilization Equipment Fastened in Place. The totalrating of utilization equipment fastened in place, other than
luminaires, shall not exceed 50 percent of the branchcircuit
ampere rating where lighting units, cord-and-plugconnected
utilization equipment not fastened in place, or
both, are also supplied.

 

[Exmark]

I'm unsure if the light is in the pool, or outside the pool. Would it matter either way?

Great point with 210.23(A)(2), I hadn't considered that. This pump should have a FLC of 10 amps according to 430.248. This would be within the "shall not exceed 50%" if I understand correctly. Pushing the limits though for sure...

Do you see any other potential code issues? (particularly with using a Multi-wire branch circuit)

Thank you,

Exmark

 

[ActionDave]

.... Can a multi-wire branch circuit feed 120v and 240v loads at the same time according to the NEC? My gut tells me no, but I can't find a specific reason....

The answer is yes.

210.4(C) Line-to-Neutral Loads. Multiwire branch circuits
shall supply only line-to-neutral loads.

Exception No. 1: A multiwire branch circuit that supplies
only one utilization equipment.

Exception No. 2: Where all ungrounded conductors of the
multiwire branch circuit are opened simultaneously by the
branch-circuit overcurrent device.

 

[Dennis Alwon]

I'm unsure if the light is in the pool, or outside the pool. Would it matter either way?

Great point with 210.23(A)(2), I hadn't considered that. This pump should have a FLC of 10 amps according to 430.248. This would be within the "shall not exceed 50%" if I understand correctly. Pushing the limits though for sure...

Do you see any other potential code issues? (particularly with using a Multi-wire branch circuit)

Thank you,

Exmark

It may matter in that the pool light must be in conduit all the way to the panel.

 

[Exmark]

The answer is yes.

210.4(C) Line-to-Neutral Loads. Multiwire branch circuits
shall supply only line-to-neutral loads.

Exception No. 1: A multiwire branch circuit that supplies
only one utilization equipment.

Exception No. 2: Where all ungrounded conductors of the
multiwire branch circuit are opened simultaneously by the
branch-circuit overcurrent device.

I kept falling back to the same code section while searching for the answer. So far I agree that the answer is yes. Thank you ActionDave.

It may matter in that the pool light must be in conduit all the way to the panel.

Thank you Dennis. I will add that to my things to refresh on.

This is an existing installation that is roughly 15 years old (I did not perform the installation.) The home owner purchased a 230v pump to replace his 120v pump. He did not realize that his main panel is completely full.

There are currently (2) 20 amp single pole breakers being used for over current protection, one for each leg of the 12-3 (no, they do not have handle ties:happyno His basement is finished of course, so running another circuit would be difficult. The original pump was not GFCI protected (I don't believe code required it when the installation was performed.)

I am trying to figure out if I could have installed a 2 pole 20 GFCI breaker and used the existing 12-3 to feed the 120V and 230V loads (switching over to THHN/THWN with conduit in the wet locations, insulated equipment ground, etc.)

I do not work on pool equipment very often, so I decided to play it safe and recommended that that he returned the 230v pump, and purchase a 120v pump. I am just hoping to find clarification for future reference.

The thing that I find scary is that the gentleman that installed the 230v pump (everything besides power obviously) did not realize that 15A and 20A pool pumps need to be GFCI protected... Supposedly "he installs hundreds of pumps and he's never seen any of them GFCI protected." He clearly thought that I was delusional and he wasn't interested in the NEC code section that says otherwise :slaphead:.

Thank you both again. Any more information or confirmation would be greatly welcomed.

Exmark

 

[Dennis Alwon]

The thing that I find scary is that the gentleman that installed the 230v pump (everything besides power obviously) did not realize that 15A and 20A pool pumps need to be GFCI protected... Supposedly "he installs hundreds of pumps and he's never seen any of them GFCI protected." He clearly thought that I was delusional and he wasn't interested in the NEC code section that says otherwise :slaphead:.

Thank you both again. Any more information or confirmation would be greatly welcomed.

Exmark

Back in 2005 NEC Gfci was not required for direct wired pumps

 

[Exmark]

They require them now though. 2005 was so last decade . The gentleman that installed the pump did not do the original installation either. He just installed the new pump. He is going around and doing this for a living without even realizing that they need to be GFCI protected now..

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[david]

if the lighting circuit could not be brought up to code including an un-spliced equipment ground i would not touch this installation, unless the lighting circuit was disconnected and the home owner signed stating that the lighting circuit would not be re-energized

 

[cpinetree]

if the lighting circuit could not be brought up to code including an un-spliced equipment ground i would not touch this installation, unless the lighting circuit was disconnected and the home owner signed stating that the lighting circuit would not be re-energized

:thumbsup: 10 X THIS!!

 

[Exmark]

Roger that. Thanks fellas.

 

[Smart $]

...
The thing that I find scary is that the gentleman that installed the 230v pump (everything besides power obviously) did not realize that 15A and 20A pool pumps need to be GFCI protected... Supposedly "he installs hundreds of pumps and he's never seen any of them GFCI protected." He clearly thought that I was delusional and he wasn't interested in the NEC code section that says otherwise :slaphead:.
...

Back in 2005 NEC Gfci was not required for direct wired pumps

They require them now though. 2005 was so last decade . The gentleman that installed the pump did not do the original installation either. He just installed the new pump. He is going around and doing this for a living without even realizing that they need to be GFCI protected now..

Exmark

Replacing a pump, and just the pump, is not the same as installing a from scratch a MWBC with a pump.

I don't do pools and such, but I believe many AHJ's wouldn't flag the installation for no GFCI because it is "grandfathered" compliant.

 

[iwire]

Replacing a pump, and just the pump, is not the same as installing a from scratch a MWBC with a pump.

In my area the reality is a simple pump replacement is going to be done without permit or inspection.

I don't do pools and such, but I believe many AHJ's wouldn't flag the installation for no GFCI because it is "grandfathered" compliant.

Neither do I, but in this area for better or worse I would expect the inspector to ask for a GFCI if it was an inspected job. Regardless of grandfathering or our 'Rule 3'.

They like GFCIs, we have inspectors 'ask' (AKA require it or get ready for an inspection with a microscope) for all standard receptacles on a bare slab store, or for refrigerators they consider vending machines and on and on.

 

[Smart $]

In my area the reality is a simple pump replacement is going to be done without permit or inspection.

Neither do I, but in this area for better or worse I would expect the inspector to ask for a GFCI if it was an inspected job. Regardless of grandfathering or our 'Rule 3'.

They like GFCIs, we have inspectors 'ask' (AKA require it or get ready for an inspection with a microscope) for all standard receptacles on a bare slab store, or for refrigerators they consider vending machines and on and on.

Reality does set in from time to time. That's why I dream when and while I can.

 

[david]

In my area the reality is a simple pump replacement is going to be done without permit or inspection.
Neither do I, but in this area for better or worse I would expect the inspector to ask for a GFCI if it was an inspected job. Regardless of grandfathering or our 'Rule 3'.

They like GFCIs, we have inspectors 'ask' (AKA require it or get ready for an inspection with a microscope) for all standard receptacles on a bare slab store, or for refrigerators they consider vending machines and on and on.

Replacing a pump, and just the pump, is not the same as installing a from scratch a MWBC with a pump.

I don't do pools and such, but I believe many AHJ's wouldn't flag the installation for no GFCI because it is "grandfathered" compliant.

I have as much respect for the two of you, but lets be careful here the most that can be said is this installation was existing when the OP got involved. The pump was never (retaliative term) compliant without GFCI protection of the multi wire 120 volt branch circuit supplying the pool pump, pool lighting and additional rec. in the pool area.

"Conductors. Conductors on the load side of a ground-fault circuit interrupter"

Conductors. Conductors on the load side of a ground-fault circuit interrupter or of a transformer, used to comply with the provisions of 680.23(A)(8), shall not occupy raceways, boxes, or enclosures containing other conductors unless one of the following conditions applies:
(1) The other conductors are protected by ground-fault circuit interrupters.
(2) The other conductors are grounding conductors.
(3) The other conductors are supply conductors to a feed-through-type ground-fault circuit interrupter.
(4) Ground-fault circuit interrupters shall be permitted in a panelboard that contains circuits protected by other than ground-fault circuit interrupters.

Further as Dennis pointed out the branch circuit for the pool light in no way meets the NEC requirements for a pool lighting branch circuit.

 

[iwire]

I have as much respect for the two of you, but lets be careful here the most that can be said is this installation was existing when the OP got involved.

For me, living in MA and I am sure for the all other electricians the fact that something was never compliant does not change what I am responsible for today.

Any conditions that existed before our arrival are issues for the inspector and the property owner.

While the following two rules are from MA I bet the reality is most areas the written rules are similar. I am not talking about inspectors shirt pocket rules such as 'You are working here, you must bring things into compliance before I pass the work you actually did do' I am talking about actually written policies. I doubt any written policy makes a EC responsible for the correction of work they did not do.