Questions tagged [mwbc]
Use this tag for questions about Multi-Wire Branch Circuits, sometimes called "Edison circuits".
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Can I run one or more cables through conduit? [duplicate]
I'm running outlets in my workshop. The wall has modular insulation blocks, which have a wiring channels already designed into them, so running cable through the wall is not difficult; I've already ...
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Multi Wire Branch Circuit for Kitchen Small Appliances Circuit, AFCI and GFCI required
I need to redo the electrical in my kitchen. I want to add an EMT ring around the kitchen with two lives and a neutral inside in a multi wire branch circuit configuration for the two required small ...
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Can't figure out this multi-wire branch circuit
I recently replaced my kitchen island, and found out that I have some MWBC in my home. I figured it out and the new receptacles are working.
On a separate line, at the countertop, I went to replace a ...
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Need advice tracing and troubleshooting old to new wiring and an accidental ring circuit in 100 year old US house
I'm in the US (Minnesota) in 100 year old house that has a c.1980 Square D 150 amp panel. I am working to de-energize some knob-and-tube I've recently discovered that is buried under insulation in the ...
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Derating for wires in conduit
I'm wiring my workshop (standalone 200-amp service) and running wires in 1-1/4" PVC conduit under the slab from the breaker panel on one wall to another wall about 50 feet away. I have one 50-amp ...
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Can I wire a MWBC with GFCI's using separate neutral wires on the load terminals?
I want to wire the circuit shown in the attached image in my garage. I want to have two circuits, and they need to be GFCI protected due to being in the garage. I've read through a number of posts ...
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Tesla model 3 6-20 charging from existing circuit
I have a 20amp double pole 240v breaker suppling power to my 120v dishwasher and garbage disposal. They share the same circuit. It’s 12-3 awg and I have a access to this circuit before it runs to my ...
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Radio transmitter nuisance tripping AFCIs
I've got a DC powered ham radio in a spare bedroom converted to an office, with a coax feedline running up to an antenna up in my attic near the ridge. About six months ago, I upgraded my feedline to ...
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MWBC old outlet to new 2 connection outlet usb Cand A
I am updating my outlets to leviton usb A and C outlets. The new outlets only have hot common and ground.
My old outlet has a white, black and red.
It appears to have its own breaker from the other ...
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Why are MWBC's permitted by NEC, given the neutral can take up to 2x the rated current?
I'm familiar with MWBCs and how they're used, especially as a cost saving mechanism when running home-runs for nearby circuits (e.g. dishwasher + food disposal).
What I don't understand is how these ...
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multi wire branch circuits with 12/3 cable for 6-20r and 5-20r receptacles on the same circuit in a workshop
I am planning on similar MWBC wiring in a new shop we are constructing (40x30 pole barn). I plan to use a double pole 20 amp GFCI breaker for each circuit in a 200 amp panel, and put at least one ...
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MWBC and GE Spacesave dual-pole breaker spanning over different pole/phase
I have 3 multi-wire branch circuits. And two of the 3 set of MWBCs were each put on same phase. An oerloaded neutral has occurred on one MWBC. (It was actually the case of oxidation, not overload, ...
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Existing same-phase multi-wired branch circuit
Bought a 1960s home with aluminum wiring.
I noticed that I have two sets multiwire branch circuit? (also known as "multiwire circuit", "multiwire branch circuit", "shared ...
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Can you cut the outlet-bridge clip and run a 2-phase MWBC to a single receptacle?
Many outlets have a bridge clip on each side of the receptacle. (I have seen these used for things like making one outlet switched on one side but always-on for the other.)
Question: If you have a ...
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I installed a new outlet and tripped the whole power panel... Does a 30 amp circuit need special outlets?
So... I tried swapping two outlets in my kitchen, and tripped the entire power panel!
The old outlets were wired with FOUR wires: red, black, white, bare.
I wired the new outlets using the same ...
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When did Handle Ties become mandatory for MWBC?
Original Question
I was extending a circuit in my kitchen last week as part of a remodel and discovered something that had been under my nose the whole time I've lived here but I just paid enough ...
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Multiwire Branch Outlet GFCI/AFCI breaker need but no product
I have a multiwire branch circuit (MWBC) connecting my dishwasher and disposal that connects to a Cutler-Hammer (using Eaton breakers) panel. After a renovation, an inspector told me I need the ...
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Sharing Neutrals - How To Correct?
I have a 12/3 NM cable landing on two separate 20 amp breakers sharing a neutral between the two. They are landing on a Dishwasher/Garbage Disposal outlet.
I understand this is NOT to code since there ...
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Is this MWBC setup allowed?
I'm continuing to fix the issue introduced by someone else (Why run the same phase twice to a series of outlet?).
The other room they did has this setup:
a 3-conductors cable brings the same phase ...
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Replacing single duplex outlet on MWBC with two of them in kitchen?
My kitchen has a single duplex outlet (so two devices can be plugged in) on a multiwire branch circuit. I'd like to tear that out, replace it with a larger box and install two GFCI duplex outlets.
...
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Changing Tandem Breakers with Potential Unmarked MWBC
I have two adjacent 20A tandem breakers in my panel. I need to change one of the breakers on each tandem to 15A (in order to protect 14 gauge wires on the respective circuits).
The possibility exists ...
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House Wired Incorrectly? - MWBC [duplicate]
I am working on finishing my basement. In my basement there is 3 junction boxes fed by 12/3 wire. Each junction box feeds a single 12/2 line (White-White, Black-Black, Ground-Ground, Red-Nothing). My ...
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Is a 120V/208V MWBC good enough for 240V loads?
As detailed in a previous post, I was planning to use the dryer circuit in my condo as a MWBC. A 120V/20A outlet between one of the two hot conductors and neutral would power my small washer and dryer ...
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Replacing receptacle & switch on a MWBC in kitchen
Background:
The house was built in 1983.
Previous owner(s) have been creative on some DIY projects around the house. The receptacle was wired half direct & half sideways.
Problems:
The switch on ...
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How can I safely utilize a dryer outlet to power 100V and 220V loads?
In my house there is a dryer outlet that, even though inconvenient to me (my dryer is 120V), I don't want to eliminate for house reselling reasons. As it was until now a 3 prong outlet, I have been ...
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Shared neutral on two circuits using a single-pole tandem breaker
I just looked inside of my sub-panel for the first time, which has ten single-pole tandem breakers. They all have two black wires connected, except for one breaker, which has a black wire and a red ...
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MWBC with both circuits on the same bus -- any easy fixes?
While moving some wires around in my garage (to make space for attic storage), I discovered an electrical issue that might be concerning: In my garage there are two circuits delivered as a MWBC, but ...
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Is this a bunch of wrong MWBCs?
I've just opened up my main panel with the plan of adding a new circuit, but have temporarily aborted that idea after squinting for a while, followed by getting worried.
I put some pictures from more ...
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Wiring for switched NEMA 6-20R and 5-20R in same box in garage
My goal is to have 20A receptacles in a particular spot in my garage dedicated to power tools (such as saws) whose motors can be configured for either 240V or 120V, with a switch as a handy second ...
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Look over father's plan to fix outdoor electrical circuit
So to begin with, I am not a DIY'er when it comes to electricity. I prefer to allow the professionals to handle these matters as it's not something I'm confident in and not too knowledgeable about... ...
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Splitting 240V into two 120V Circuits
I think I have this figured out for the most part but looking for validation from expert strangers on the internet.
Renovated the kitchen in this 1960's house. I think it probably has been renovated ...
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GFCI breaker on a MWBC (Shared common)
We are doing kitchen reno. We had to replace the main breaker panel. Local code requires we use arc fault breakers. This is not an issue for most of the project, however, the inspector is insisting ...
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GFCI receptacle connected to Multi-Wire Branch Circuit
I have a Multi-wire branch circuit & would like to connect GFCI receptacles. The MWBC currently powers dimmable LED lights in basement. In process of finishing basement. I would like to extend ...
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Identifying what receptacles and fixtures are on each branch of a MWBC
How should I safely identify which breaker controls which fixtures & receptacles in a Multi-Wire Branch Circuit? There is intentionally a handle tie for the MWBC in my panel which must be kept to ...
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Disposal Circuit Update
I moved to a house built in 1995 and want to update the disposal connection, but found some conflicting rules that I don't know how best to comply with.
The existing connection is a 14-2 NM cable run ...
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3 phase MWBC - 2 pole breaker with shared neutral
I’ve searched around and can’t quite find an answer to my question.
I understand that you can share a neutral on a 3 phase panel if you use a 3 pole breaker. But can you still share a neutral on a 3 ...
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MWBC exists, use for bathroom?
I am finishing my basement. The previous owner had ran a MWBC to the area that will be the bathroom. In the panel it is two 1-pole 20amp breakers. My questions are:
First to confirm, it seems I ...
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MWBC for split kitchen receptacle
When installing a split receptacle in a kitchen, where the top and bottom are each their own circuit, is there any way you can use an MWBC, or is your only option to run two normal circuits with two ...
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Can I have an MWBC plus another circuit in the same junction box?
The conduit coming in on the left carries a 15 A MWBC. In this junction box, it splits to the brown-to-black wire for the furnace, and the orange wires to some basement lights (top) and an upstairs ...
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Two Circuits on a Single 12/3 - Shared Neutral
I was recently trying to upgrade a 20A breaker supplying outlets in my kitchen and dining room to a CAFCI breaker. When I opened my breaker box I saw that the neutral on this circuit was shared with ...
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Multi-Wire Branch Circuit on wrong breakers
My electrical panel has a double-pole breaker that looks like it's for a MWBC, but actually the attached wires are from different cables.
In the below picture the black wire with the yellow rubber ...
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In a multiwire branch circuit, can the two hots be connected to the same phase?
This may be an obvious question, but I haven't been able to find a direct answer.
I believe I have a MWBC - I have two hot wires connected to two separate circuit breakers, sharing a neutral and ...
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Is this a weird or very problematic shared neutral?
I will try to explain it and I made a drawing that give an idea of what it seems to look like.
I just had some work done on my house (built in 1967) and the electrician found this weird connection.
I ...
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Neutral pigtails on MWBC
I've recently moved into a new home with a few outbuildings. Due to the property being in rural unincorporated area, no inspections or permitting was required on the outbuildings when they were built ...
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2 independent GFCI (or 2-pole GFCI) outlet in 1-gang box. Does that exist?
I have a 1-gang duplex outlet under the sink in my kitchen. The two outlets are on separate phases of a single MWBC circuit. One of them powers the garbage disposal, and is controlled by a switch. The ...
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Is it possible to wire 2 GFCI receptacles on 2 circuits with 12/3 wire shared neutral?
I am planning to run a few needed 20amp outdoor receptacles (and therefore want GFCI). My plan was to run 12/3 wire from 2 separate circuits in the panel to a double gang weatherproof box with 2 gfci ...
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MWBC and very low power factors
The principle of an MWBC is that two hots can share a neutral if they're on opposite phases, since the current on the neutral will cancel instead of adding. But isn't this only true for loads with ...
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Diagnosing a suspected multi wire branch circuit
Last week I lost power to my new garbage disposal. I opened the box to find this:
There are three cables coming in from the bottom. Two of these are somewhere downstream from the Panel, not too sure. ...
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Convert MWBC to single 240V receptacle
I currently have a 20 amp double pole breaker supplying a multi-wire branch circuit for two 120v receptacles in a double gang box.
I'd like to remove the 120v receptacles and install a 240v receptacle....
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Is this a MWBC?
I think I have some MWBCs that are not handle tied. Can you tell from this picture if the bottom red breakers and top blue breakers are MWBCs? I can't trace back to the conduit and they supply "...
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