120V quad outlets- multiple circuits

[tealetm]

I'm planning out the inside of my new woodshop and would like to install multiple general use quad outlet boxes at 50" above the floor, probably every 6' or so on all walls. (Yes I have to have these outlets GFCI protected but that doesn't really come into the question at hand)

Its a one man shop, but I like the idea of having two different circuits in one quad box, say one powering the left side duplex and the other circuit powering the right side just in case I'd ever be using two tools at once that would trip the breaker (or a space heater/tool or air compressor/tool, you get the point). Repeat this all throughout the shop so all these quad boxes are internally split between two circuits.

Am I crazy for thinking like this? It would be lots of wire, two in and two out of each box but I don't see any other way (I think I'll avoid multi wire branch circuits just to avoid confusion in the future)

 

[mike93lx]

What confusion would a mwbc cause? It's a simple way to do it and saves a wire.

 

[tealetm]

What confusion would a mwbc cause? It's a simple way to do it and saves a wire.

I'm just not familiar with it that's all- but maybe its time I become familiar with it. Running one 12/3 wire box to box around 110' of wall space would indeed be cheaper and simpler than running two 12/2 wires...

 

[mike93lx]

I'm just not familiar with it that's all- but maybe its time I become familiar with it. Running one 12/3 wire box to box around 110' of wall space would indeed be cheaper and simpler than running two 12/2 wires...

It's really the perfect application for it. Two pole breaker, GFCI's in the first box and you are good to go.

 

[TRWham]

I'm just not familiar with it that's all- but maybe its time I become familiar with it. Running one 12/3 wire box to box around 110' of wall space would indeed be cheaper and simpler than running two 12/2 wires...

It might be simpler, but possibly not cheaper. Check the price of cable locally and you may find that 2x quantity of 2 conductor is not >=2x the price of 3 conductor, especially when you factor in quantity price breaks.

 

[PelicanPines]

This is a true story... I bought a house that was rewired by the previous home owner, who was a professional. ONE outlet next to the basement sink ... I wanted to eliminate it and rewire it in a different location with new wire. Everything HE DID was with BX metal armored cable. I stuck a line tester in the outlet... flipped the breaker... power was off. I pulled the box off the wall... disconnected the BLACK WIRE in the breaker panel. Grabbed a hack saw and started cutting the box off the BX by the sink. Bare hand on the metal armored cable... cutting thru it. I was suddenly faint and realized I was being electrocuted.

The previous professional guy... used 3 wire cable... Had the RED wire on a different breaker... decided he didn't need the live end so cut the red wire flush with the box I just pulled off the wall. He setup a suicide situation for the next person.

Before you chime in... this PREDATES those cheap voltage tester pocket things. I DID check the box and only saw the black live wire and neutral and ground. I tested the wires with a METER before disconnecting at the breaker box.

Two sources of power into a box can be dangerous. If not you... for the person who inherits your location.

It sounds like you are putting in a number of boxes... don't put two sources of power into one box... alternate them. Label them Line A, Line B.

 

[mike93lx]

Two sources of power into a box can be dangerous. If not you... for the person who inherits your location.

Two pole, handle tied breaker makes that a non issue. Both get shut off at the same time

 

[yatg]

It's really the perfect application for it. Two pole breaker, GFCI's in the first box and you are good to go.

need separate neutrals past the GFCIs.

 

[mike93lx]

need separate neutrals past the GFCIs.

Dammit, you are right

 

[TobeyA]

My shop is wired like you are thinking. Left and right sides of each box on separate breakers. Works fine for me.

 

[PelicanPines]

Two pole, handle tied breaker makes that a non issue. Both get shut off at the same time

YES tied breakers... in my case that would have been the solution... over the years... breakers change... swapped around... new wiring... etc. I could not justify a reason to have dual sources of 110 power in one box split between two sets of outlets. If you are running vacuum ...have that plugged into the second set of outlets... compressors in my life are dedicated lines... so what would be a valid purpose of putting two sources in one box? Provided you have multiple boxes to begin with... why put two sources in one?

Just because you can do something doesn't mean it should be a hold my beer thing.

 

[mike93lx]

YES tied breakers... in my case that would have been the solution... over the years... breakers change... swapped around... new wiring... etc. I could not justify a reason to have dual sources of 110 power in one box split between two sets of outlets. If you are running vacuum ...have that plugged into the second set of outlets... compressors in my life are dedicated lines... so what would be a valid purpose of putting two sources in one box? Provided you have multiple boxes to begin with... why put two sources in one?

Just because you can do something doesn't mean it should be a hold my beer thing.

Two circuits saves you from buying and installing a second box. I have one in my garage and it's great when I have my table saw or miter saw setup with my large shop vac. Extension cords run to one spot.

Works great, but that doesn't mean you need it in your shop.

I install stuff safely and in a code compliant manner. I don't worry about someone down the line doing something dumb

 

[tealetm]

Dammit, you are right

So is the option of multi wiring branch circuits really not an option if I have to run separate neutrals after the GFCI's anyway?

 

[PelicanPines]

Two circuits saves you from buying and installing a second box. I have one in my garage and it's great when I have my table saw or miter saw setup with my large shop vac. Extension cords run to one spot.

Works great, but that doesn't mean you need it in your shop.

I install stuff safely and in a code compliant manner. I don't worry about someone down the line doing something dumb

I have one 20amp 4 gang plug. My 30 gallon compressor. My Ridgid table saw. My Dewalt 12" chop saw. Are all plugged into that 4 outlet box. My vacuum is on a 2nd circuit that's 15 amp. I never need to run the compressor, with either saw... nor would I use both saws at the same time. My point is... there is never a need to put two sources of 110 in a single box, that's all I am trying to say.

 

[mike93lx]

So is the option of multi wiring branch circuits really not an option if I have to run separate neutrals after the GFCI's anyway?

If you are going to have them in the same boxes, I'd still use a two pole breaker, but yeah, it means you would be running separate neutrals.

Aside from the gfci issue, it's a great application for mwbc, but being in a shop, you need the gfci

 

[mike93lx]

I have one 20amp 4 gang plug. My 30 gallon compressor. My Ridgid table saw. My Dewalt 12" chop saw. Are all plugged into that 4 outlet box. My vacuum is on a 2nd circuit that's 15 amp. I never need to run the compressor, with either saw... nor would I use both saws at the same time. My point is... there is never a need to put two sources of 110 in a single box, that's all I am trying to say.

There isn't a need to do a lot of stuff. Doesn't mean mean you can't or that there isn't a benefit.

I'm glad you have a setup that works well for you.

Having two circuits in a box is safe though

 

[RonnieC]

My shop is wired like you are thinking. Left and right sides of each box on separate breakers. Works fine for me.

That’s what I’m doing in my new woodworking shop, but I just ran them down one wall where I thought I’d be using power tools.

 

[PelicanPines]

There isn't a need to do a lot of stuff. Doesn't mean mean you can't or that there isn't a benefit.

I'm glad you have a setup that works well for you.

Having two circuits in a box is safe though

Agree to disagree.

 

[mike93lx]

Agree to disagree.

No way.

Disagree to agree

 

[ycgoat]

Is there a code requirement for the separate neutral past the first outlet? Other wise you could use individual GFCI at each location.

 

[dcg9381]

I'm just not familiar with it that's all- but maybe its time I become familiar with it. Running one 12/3 wire box to box around 110' of wall space would indeed be cheaper and simpler than running two 12/2 wires...

That's how I did dad's wood shop. I didn't use quads though, I just alternated duals every 3-4' off 12/3 and a dual pole breaker.

 

[rlitman]

Is there a code requirement for the separate neutral past the first outlet? Other wise you could use individual GFCI at each location.

That's an option, but the second neutral wire is cheaper than the truckload of GFCI's you'd need if you wanted to skip using the load terminals.

 

[eejack]

So as an alterative, run two totally separate receptacle circuits in different alternating boxes, 6 feet apart. The likelihood of being out of range of both circuits is zero ( most appliances, tools have a 6' cord ).

Honestly it would be cheaper to space them further apart and purchase a couple of very good and relatively short extension cords. Maybe a cord reel or two strategically placed might make some sense.

 

[yatg]

Siemens and probably others make a 2 pole 20A 120/240 GFCI breaker. Ain't cheap.

https://www.amazon.com/dp/B01HQGLX06/?tag=atomicindus08-20

 

[alfredeneuman]

Re: The MWBC
To save some $ (Those 2 pole GFIs are expensive)
Just run 2 separate neutrals (and keep track of which one is which) to each box.
That way you can use 2 GFI receptacles (and the other recps. on the load side) with single pole breakers. A bonus is if you accidentally trip one breaker the other won't trip (as with a 2 pole).
The amount of wire involved will cost much less than the breaker.

 

[dscheidt]

That's an option, but the second neutral wire is cheaper than the truckload of GFCI's you'd need if you wanted to skip using the load terminals.

A shop I used to work in was wired like this. there two 20A circuits for the general purpose outlets, wired as a MWBC. Each location had a 1900 box, with two GFCI receptacles. they get tripped enough that the expense of a bunch of gfcis is less than the hassle of dealing with your drop light going dead because Cletus drill a hole in a bottle of antifreeze.

 

[dmittz]

Could I bring up a suggestion... instead of running two circuits into a 2 gang 'quad' box, why not just just do two 1 gang boxes close together on seperate circuits, you get all the benefits and no downsides...

 

[mogandave]

I would do closer together, duplex single boxes, odd boxes on one circuit, even boxes on the other. Odd box covers white, even box covers brown.

As I remember, wire & recepticles are expensive, while boxes, covers and holes in the wall are cheap.

 

[alfredeneuman]

duplex single boxes

What do you mean by duplex single boxes?

 

[Zeke]

What do you mean by duplex single boxes?

What do you call a duplex receptacle in a single gang box? He just left out a couple of words.

 

[alfredeneuman]

What do you call a duplex receptacle in a single gang box? He just left out a couple of words.

Duplex outlets in single gang boxes aka "handy boxes" are useless and ought be outlawed (IMO) There is not enough room in them.
A 4" square box with a raised cover or a mud ring is the way to go.
Edit: $1.57 for the handy box vs: $1.96 for 4-S box at HD

 

[Zeke]

Duplex outlets in single gang boxes aka "handy boxes" are useless and ought be outlawed (IMO) There is not enough room in them.
A 4" square box with a raised cover or a mud ring is the way to go.
Edit: $1.57 for the handy box vs: $1.96 for 4-S box at HD

I totally agree especially when a GFCI is involved. I see what you are asking now, What kind of single box?
I do like handy boxes and metal covers that fit the profile and not overlap on surface mounted work. 2-gang work very well with a single duplex recep and cover.

 

[n8n]

What confusion would a mwbc cause? It's a simple way to do it and saves a wire.

The one downside I can think of to that plan is if you trip the breaker on one circuit it's going to trip the other one as well (assuming a code compliant installation). Using two separate neutrals will allow the use of independent breakers.

 

[mike93lx]

The one downside I can think of to that plan is if you trip the breaker on one circuit it's going to trip the other one as well (assuming a code compliant installation). Using two separate neutrals will allow the use of independent breakers.

Could be a downside, sure.

In my shop, if I am using two 120v circuits simultaneously, tripping one stops work anyway, so having them tied wouldnt present an issue.

 

[dave*99]

GFCIs and MWBCs when used together need special consideration as some have noted.

I'll add another vote for 2 separate circuits feeding alternating circuits down the wall every 6 feet or whatever works for your situation.

Someone mentioned using white and brown covers to make it obvious which receptacle is on what circuit. An alternate method is to orient receptacles with ground up on one circuit and down on the other. I suspect either of those choices would get my OCD in a bunch.

 

[sparky 1971]

The one downside I can think of to that plan is if you trip the breaker on one circuit it's going to trip the other one as well (assuming a code compliant installation). Using two separate neutrals will allow the use of independent breakers.

If a two pole breaker is used. If a handle tie is used, chances are the other circuit won't trip. It will have to get shut off in order to reset the other breaker though.

 

[Joemctag]

GFCIs and MWBCs when used together need special consideration as some have noted.

I'll add another vote for 2 separate circuits feeding alternating circuits down the wall every 6 feet or whatever works for your situation.

Someone mentioned using white and brown covers to make it obvious which receptacle is on what circuit. An alternate method is to orient receptacles with ground up on one circuit and down on the other. I suspect either of those choices would get my OCD in a bunch.

What I do is when I downy electrical work Oman existing building, I start clearly marking anything I discover, so it’ll be known in the future. In a shop, I write, say “12” and “14” in black sharpie at the top of the 4-gang box cover over the side those circuits feed. If the numbers aren’t clear in the panel, I’ll re-write those too. I also don’t hesitate to write on junction box covers or, say conduits coming from or to a box with arrows and, say, “to receptacles/north wall”, or whatever.
My house has the panels covered with a large mirror on hinges, and the back has a scale map of the house with ALL receptacles, light fixtures, anything , marked and in color for each circuit. Also, drawing of the fuse boxes and sub-panel similarly color coded. I can see at a glance what feeds what and have a pretty good idea of how the wire is run from point to point.
No pencilled in stuff on the panel for me.

 

[Wrench97]

Not sure of the current code but years back if you ran 240v out of the panel and split the circuit in the box to 120v you were not required to have GFCI.

 

[Norcal]

Not sure of the current code but years back if you ran 240v out of the panel and split the circuit in the box to 120v you were not required to have GFCI.

120V receptacles have been required to be GFCI protected in garages for decades.

 

[Samh]

I'd just run 2 circuits. You'd only be saving 1 wire using a mwbc