Electrical decision time and advice requested

[Ken Fitzgerald]

Folks.....I am at the point of starting the electrical rough-in today. I need some advice. My new shop is 30'x24'. One wall has a 36" entry door and a 10' insulated garage door in it. Each of the 30' walls will have 8 120vac outlet boxes. The one uninterrupted 24' wall will have 6 120vac outlet boxes. The 24' wall with the doors will have 2 120 outlet boxes. I am wiring the 120 outlet boxes with 12-3 using the "Edison" concept. What I need advice on is the number of 220 outlets you'd recommend. I am considering 3 220vac in each of the 30' walls.......2 in the uninterrupted 24' wall and one in the 24' with the doors. I am planning on using 10-2 wire for the 220 outlets. The catch is that each of the 220vac outlets have to be on a separate circuit and breaker and takes up 2 spaces in the breaker panel. I am planning to keeping enough space open so that I could add a 220vac 60 amp outlet immediately below the panel, in case I might learn to weld and need same for future use. Any suggestions?

[Steven Wilson]

I would run the 220V lines in conduit, surface mounted once I have the tools placed and then run what is needed.

[Dick Bringhurst]

Ken, have you considered putting a couple of 120 outlets in the ceiling so you can mount self retracting extension cords. They sure come in handy especially over the assembly area. Dick B.

[Ken Fitzgerald]

Dick.....yes I'll place some 120 outlets in the ceiling for that very reason....thanks for the suggestion.....I'd thought about it ....and forgot about it......

[Tyler Howell]

Hey Ken.

I like Steve's Idea. You've heard me rant about conduit. Just because it's run doesn't mean you have to hook it up. As you get use to your shop, make changes and stettle in you may find you'd like another arangement. You've planned ahead, it's a matter of some simple changes. Just make sure you ID every ckt.
Good luck and play safe!;)

[Wes Bischel]

Ken,

When my dad did the layout for my garage (I was the grunt - he was the brains), he had me run two seperate circuits to each of the quad boxes along the back wall (I used 110 until the 220 was needed). That way when I bought my compressor, I had 220V at any of the boxes. I cannot remember the exact layout, but the inspector thought everything was okey dokie. Maybe one of our resident electricians knows the details.

Just food for thought.

Wes

[Jim Becker]

It's hard to recommend a placement for 240v outlets since they are more dependent on tool location than 120v setups. You may actually need one or more overhead in the future as your tool collection changes. Frankly, some of my 240v circuits have changed location several times over the past five years as new tools were aquired and the shop layout evolved. Keep that in mind since flexibilty is key to that.

BTW, you can have more than one 240v outlet on a circuit, but you cannot daisy chain them. Branch off in a large j-box. But keep in mind that certain things do need to be on a dedicated circuit, such as the DC and the compressor, since they conceivably could be used concurrently with other tools.

[Gary Max]

My bandsaw was drawing to many amps and I had to run a single line overhead for it.
I used 10 gauge wire and made the run straight from to box to the saw. Having the least amount of wire that was a larger size made everything safer. I still had to replace the motor but ended up with a nice outfit.

[Ken Garlock]

Hi Ken.

If I were you, based upon what was done on my shop, I would put 4 240V 20A circuits along the 30' walls. I would decide where I wanted/needed 240V 30A circuits and locate them.

What you need to accommodate all these circuits is to install a sub panel. right next to your current distribution panel. Put a 100A breaker in the main box, and wire in the sub panel with some heavy gauge wire, like #4. Then you should have sufficient slots for all the breakers you will need. Remember, you do not jumper the neutral and the earth ground in the sub panel, only at the main.

Do it right now, and not have to mess with conduit on the walls later :eek:

[Steve Cox]

I am actually at the finishing stage of re-wiring my 20 x 25 shop (2 car garage). I would recommend that you sit down and do a plan of where your 220v tools will be and install accordingly. In my shop I have a tablesaw, jointer, planer, bandsaw, cyclone, and air compressor, all 220v. My bandsaw and tablesaw are powered by drop cords from the ceiling and all the others are off one wall in the shop because that's where the tools are. 115v I can see placing evenly around the walls, that's what I've done too. 220v is a different story. As you said each one takes its' own circuit and that takes up room in the box. BTW, because my walls were insulated but the ceiling is not (go figure:confused: ) I ran NM cable in the attic and then ran external MC drops from the ceiling. Works well for me.

[Frank Pellow]

...
220v is a different story. As you said each one takes its' own circuit and that takes up room in the box.
...


Ken and Steve why do you both say that each 220v outlet takes its own circuit? That is certainly not what I am doing with my shop.

[Frank Pellow]

I planned very carefully where I would likely place my 240 volt machines both now and in the future. This planning resulted in 3 240 volt ceiling receptacles and 3 240 volt wall receptacles. Then, just in case I am wrong, I added 5 junction boxes wired with 10/2 in other parts of the walls. There is a 2 metre loop of wire behind each of these junction boxes.

[Ken Fitzgerald]

Frank.....the local electrical code inspector made it "perfectly" clear..on my 110v circuits...because it's in a shop I could put 8 boxes....he also recommended using 12-3 and using "edison" circuits to minimize the number of cables needed to wire them. He also made it perfectly clear....I could not daisy chain my 220v circuits as I could the 110v circuits. I suspect as stated by Jim Becker I can use a junction box and parallel the 220 v circuits from there but....I'll ask the inspector before I do it. I'm not sure but this might be a local "interpretation" of the code or a local code thing.

[Steve Cox]

Frank,

It depends on what you want to run. As it was explained to me I could put more than one 220v receptacle on a ckt provided that only one tool would be running at a time or more correctly, that any combination of tools wouldn't exceed the capacity of the ckt just like 110v. Looking at current draw that meant that my cyclone and compressor each had to be on their own ckt. I suppose then that my jointer and planer could be on the same ckt as could my tablesaw and bandsaw but that only saves me two breakers and it doesn't seem worth the trouble. The other thing is that I am very conservative when it comes to power. I like lots of it and having it run far below capacity. Leaves room for expansion.

[Frank Pellow]

Frank,
As it was explained to me I could put more than one 220v receptacle on a ckt provided that only one tool would be running at a time or more correctly, that any combination of tools wouldn't exceed the capacity of the ckt just like 110v...


I agree, but thats a lot different than a regulation saying that there can only be one outlet per 240 volt circuit.

[Don Abele]

Frank, regardless of code, it's the inspectors interpretation of the code that really counts. I have never seen one relax a code, but they will certainly tighten the constraints.

In Maine I was not allowed to run more than 1 outlet per 240 breaker. But, I did not have to run GFCI outlets as the inspector said that since it was a wood shop, they were "dedicated" outlets and didn't need to be protected (this was in a under-house 2-car garage).

In Washington the opposite was true. I could run multiple outlets off of a single 240 breaker, but they had to be run in parallel from a junction box, not daisy chained inside the outlet. This inspector also mandated the GFCI protection for ALL 120 outlets, regardless of being dedicated or not.

Personally, I only run 1 outlet per breaker for 240.

Be well,

Doc

[Ken Garlock]

Ken and Steve why do you both say that each 220v outlet takes its own circuit? That is certainly not what I am doing with my shop.

In my case, it was a personal preference. If I popped a breaker, I wanted it to only shutdown the one device/outlet. Given that the code in your area permits it, you could daisy-chain the 240V 20A oulets thus saving wiring and effort. But, remember the total load on the entire circuit cannot exceed the 20A breaker rating, that might a problem depending on how you set up your 240V tools. I plan on daisy-chaining my 240V 30A circuit laid in my dust collector "ditch" down the middle of the shop, but I know in advance that I will never be running a cabinet saw, jointer, and planner at the same time.

Also used the idea posted previously of using quad boxes with each duplex outlet on a different breaker within the box. That way if you pop a breaker on one duplex, the other is still functional. Here again, personal preference. My take was that I am only building this shop once, so I wanted it flexible. :)

[Ken Garlock]

Frank, regardless of code, it's the inspectors interpretation of the code that really counts. I have never seen one relax a code, but they will certainly tighten the constraints.
Doc

Don I know exactly what you mean. When my shop was inspected, the electrican had to install GFCI duplex outlet BECAUSE I had double/french doors at one entry to the shop, and he "liked to see the GFCI" under that circumstance. I guess he figured I was going to use it as an auto repair garage, and garages need GFCI. dumb, dumb, dumb :mad:

[Chris Padilla]

What is the issue(s) with daisy-chaining 240 V outlets as some AHJs see it? I guess I need to find out if it is allowed here now.

BTW, I would avoid putting conduit on the outside of a wall (especially a brand new one!) at all costs. It is just plain ugly and can get in the way. Take lots of pics and measurements and run extra stuff for future needs. :)

[Ed Breen]

I live in a rural part of the county, there is no inspection or code! When I set up my shop I ran 110v circuits all over the place (all four walls) most were prewired boxes. Can't remember the name but they are abvout 4 feet long and have two sets of double outlets. I set my 240v lines up every 5 feet, two walls are daisy chained. Most of my motors have been set for 240v with the appropriate drop in amperage. On my ts I use 240V 3 phase, ras is 240, bs is 240. If I had my way I'd change over every motor in the shop.I figure as a one man operation I won't be using more than one unit at a time.
Ed :D

[Mike Cutler]

Ken. If I am reading your post correctly you are looking to install a total of 6 220 receptacles. My first question is do you have 6, 220 loads. Layout your equipment and see where the logical flow of work will be and then locate the receptacles. I like the idea of conduit for future modification, but conduit runs do have some special grounding requirements. You may be able to get an exception from your inspector on the individual breaker required for each receptacle, based on the fact that no more than two, or possibly three motors will be on at any one time. If your DC/Cyclone or a compressor sits on a circuit and has an auto start function, the inspector will most likely require a dedicated circuit for these. By the way, there are some specific criteria for welders in attached and detached garages, you may want to review them with your inspector so as not to have a hitch later on. The question in this thread about "Dedicated 220 Circuits" is not exactly black and white. While there is no stated criteria for dedicated circuits, there is a criteria based on theoretical expected ampacity of the circuits and this is what may be pushing you into the dedicated circuits. I would expect that the inspector, or the liscense doing the work if you have one, are basing the criteria on the largest motor size and are applying the 125% rule, this may be where you can be granted an exception. if the total ampacity of two motors on one circuit can be demonstrated to not exceed the theoretical ampacity of that circuit an exception can be granted, however with movable machines it's a hard sell. The section of the code most pertinent to what you are doing is in the section on wiring for attached and detached garages. One question i do have for you is; How did you meet the GFCI requirements on the 110 circuits with an Edison setup. I may be visualizing this incorrectly, but it seems as if the shared neutral wouldn't test properly. Maybe I'm just not thinking straght on this one. I'll wire on up at work tommorrow for fun.For the record the NEC applies to all states and local municipalities, the local munincipality may not be on the 2002 code, but it will certainley be on some prior code, ie 1999, 1996.
It sounds like your shop will be very nice when you are finished. Good luck with the rest of it.

[Chris Padilla]

What the heck is Edison wiring/setup? I've never heard of it.

[Steve Cox]

Mike,
Does the NEC (or something very similar) apply up in Canada as well? Some of our discussions on this topic have crossed the border and I was curious if we are all reading from the same book.

[Ken Garlock]

What the heck is Edison wiring/setup? I've never heard of it.

DC, isn't it :eek: :D :D

[Mike Cutler]

Steve. I would have to believe that Canada has it's own version of the "NEC". I would expect the intent to be very similar Tho'. We get power from Ontario Hydro and Hydro Quebec that comes down into the NEPEX Pool and I know we have to do something with the ground reference potential on our side of the border before it hits the grid, but 'trons are 'trons. As far as I know Canada uses 60 cycle and has nominal 120 and 220 vac residential loads. A google search shows me that the Canada Electric code was last updated in 2002. The previous version was 1990. It appears that the code in Canada is linked with the NFPA(Canadian Authority), as it is in the US. When I was in high school in the mid seventies, it was taught to us that the purpose of the NEC was to maintain and protect the integerity of the conductor, not so much personal safety, thus possibly the link and roots in the NFPA. The code is anything but black and white in the US, and I'm sure the same can be said of Canada. This is why I always advise to leave the wiring to a local reputable liscense if you are unsure.
Chris. "Edison Wiring "is the practice of sending out three condutors Black, Red and White. The Hot side is either the Black or the Red and the White, Neutral is shared between the two "hot" conductors on the return. It allows you to run a single 3 conductor cable and branch off and share a common return.It essentially saves 1 wire. The only potential fault is in some how ending up with an unbalanced return, and that was my question to Ken regarding the GFCI's

[Steve Cox]

This is making me nervous. I am in the process of fininshing a complete shop re-wire and will be calling the inspector soon. I DON'T WANT TO HAVE TO REDO THIS!!!!:eek: Mike I know what you mean about not black and white though. I have received so much conflicting advice through this it makes my head swim. I have 9 years as a Navy Electronics Tech and while trons are trons, this code stuff just doesn't make a whole lot of sense sometimes from a purely electrical perspective.

[Ken Fitzgerald]

Chris....as Mike stated Edison wiring is using 12-3 for example...you wire alternate outlets one using black/white and the next one red/white. The main advantage is using one cable to run 2 circuits. That is probably the only advantage....2 circuits 1 cable.......fewer cables and installation labor.

Mike....interesting question about the GFCI.....the inspector is the person who recommended Edison wiring even though I told him I'd heard that proposed changes to the NEC will disallow Edison wiring.....I'll be talking with him in the morning......

[Mike Cutler]

Steve. In the US there are "primers" so to speak on residential wiring, available at most Home Depot's, libraries and bookstores that cover most of the basics of code wiring requirements. I'm fairly certain something of this sort is available in Canada. In you're situation, I would contact the inspector ahead of time and talk to him. Ask him what he will be looking for, and generally be honest about what your intent is. Electrical Inspectors get a bad rep that is generally undeserved. Most of the time they are looking ahead at future potential and basing their criteria on that. With a garage shop it's hard to hide the fact that you will have multiple large load motors connected and running simultaneously. While some of the stuff may seem silly, ie a twist lock receptacle can meet the breaker line of sight requirement, but a normal convenience receptacle cannot. Most of the requirements are actually for your protection. I've yet to meet an inspector that was unwilling to work with a person, if the person was upfront and honest about what they were doing and were genuinely trying to do it correctly.
Ken. I'm sure that there is no problem with the Edison circuits. They used to be the norm in some areas of the country. It was just a question that popped into my head after a long day.

[Frank Pellow]

Mike,
Does the NEC (or something very similar) apply up in Canada as well? Some of our discussions on this topic have crossed the border and I was curious if we are all reading from the same book.

The standard in Canada is the CSA (Canadian Standards Association) which is similar to the NEC in the USA. Each provice also has its own electrical code and I do not know how much that differs from the CSA electrical code. In Ontario, there is a very well written and illustrated book (now in its 23rd edition) on residental wiring that I have used for many years. It is called "Elcetrical Code Simplified -Residenetal Wiring -Ontario Book 1".