Garage Wiring

[Red90YJ]

I just can't find a straight answer. I am purchasing my first 220V machine a MM175. My detached garage is approx 20 ft away and currently is fed by 10/2 romax.

I'm getting mixed answeres on whether this will be sufficient or to upgrade and If I have to upgrade do I go to 8,6 or 4 gauge wire. I will purchase enough cable to run through the recommended 40 amp breaker to the welder outlet.

Please, someone with experience lay down the law on this. I would like to be up and running before this weekend.

Thanks

[ventureline]

10/2 Romax, if I remember right is a solid conductor, not stranded cable. Since your welder draws what, 26 amps at 230. You should be more than fine. Still as other forums pointed out, we don't know the codes in your area, sooooooo.

You still need some sort of ground, an 8-10' lightning rod stuffed into the ground will suffice.

[Sundown]

I think that the MM175 needs 19.5 amps, so even a 20 amp breaker should work. That is unless I am wrong, it's possible I have been before. Someone please correct me if I am reading the specs wrong!

[KenCo]

ok, this is what I have. For the past 15 years or so, I've ran an old monkeyward 220v crackerbox stick welder on about a 40' 8/3 line thru a double 50 amp circuit breaker in the house box. Two months ago, I sold the ac welder and bought a MM175. The Miller is ran on the same line. The 8/3 is connected directly to the circuit breakers on on end and a 220v female receptacle that matches the welder cord plug on the other. I'm thinking about rewiring my shop with a new circuit breaker box with about 12 circuit spaces. I'm going to run number 2 wire from this box to the house power box. I also have a 50' line of 8/3 with a male plug on one end and a female plug on the other. I use this line on my gas driven Hobart Champion 16 portable welder for the MM175. Again, this is what I do, hope it helps....Ken

[Sberry]

Detatched garge wiring can be complicated. Is this 10/2 wg already a 240V wire? If so feed it with a 30A breaker,,, but there are quite a few issues with garages. You are only allowed one power feed circuit to it so usually there will be a feed to a new panel so you can branch off circuits for lighting and recepts. New panel requires a ground rod. If a garage is fed with a single or multiwire circuit there is no ground rod needed. There needs to be a disconnecting means though. Here is a link to look at for powering garages and some options.
http://www.homewiringandmore.com/homewiringusa/2002/accessory/detgarage/detgarage.html

[echo8287]

Electric Upgrade

1.Is your whole garage on the 10 wire?
2.You cannot run anything else on the 10 wire as it will be hooked to 240volts for the welder.
3.Does this wire feed lights or recepts?
4.I don't know what the MM175 pulls but if its less than 30 amps it should work(not much voltage drop in 20 feet)
5.You cannot use any 120 volt items off the 10/2 if you have it wired 240 for the welder.
6. If you are going to upgrade run a 6/3 with grd(4 wires over).It is the cheapest for the money and it will have insulated neutral for lights ,grinders,etc. then you can use the 10/2 also maybe for a large compressor,or whatever.
David
Dixon Plumbing & Electric

[Sberry]

David, if he provides a new feed to the garage he has to dicontinue the 10, the code does not allow for 2 feeds to a detatched garage.

[lranch]

If you are going to do the work yourself I would suggest the following. Locate the electrical wholesaler/supplier in your area. Talk to the person at the counter. Tell them what you intend on doing, ask them "how much" for a 100, 200amp? service panel Look on the counter. There you will find the latest NEC book AND any nasty grams for your area. Look in the book (lots of charts) (or ask any of the electricians loafing about) what size conductor, type, etc. you will need. Ask for advise (unless code) for install. I.E., overhead, bury, (don't go with the "have the ol'lady hold it up while you mow" method). You will find everything you need, stuff, advice, more advice, and Code REQUIREMENTS. Or you could give one of the electricians loafing around some candy and point towards your house. P.S. don't buy the NEC book (unless you want to) just lookup what you need. Good luck.

[Sberry]

He will never find all the details pertainent to this job in the book browsing thru it. It can take years to dechiper as they are in several different sections. Either hire it done, ask for help or do some study. I gave the link to home type jobs and even that can be confusing, here is another forum to ask questions. If he is going to be welding the need for additional equipment will add up in a hurry. A 100A panel install is almost a requirement although he may skate on a 60, but the install will be the same.
http://forum.doityourself.com/forumdisplay.php?forumid=9

[INTP]

A good book for anyone wanting to do their own home wiring is "House wiring with the National Electric Code" by Ray C. Mullin. There are two versions, and I have the smaller (cheaper) one. It's a nice reference for all kinds of things.

Maybe this is already obvious, but a 240V circuit can only have one receptacle or hard-wired device attached (with obscure exceptions, that aren't really relevant here). This means you really need a sub panel in the garage. I put one in mine just so that I wouldn't have to go inside the house to reset a breaker in case I trip one while working. The panel itself is really inexpensive. The wire costs more.

For a detached building, I really recommend running a larger wire than you think you'll need. I pulled a 4GA, with a 70A breaker feeding the subpanel. It's more than enough for now, but should I decide to get a big transformer welder, I'll need more ampacity.

[Red90YJ]

There still seems to be alot of contraversy here. I blame myself for not completely expressing my situation.

The detached garage is 20 ft away. There already is a 10/2 in 1/2" pvc pipe underground feeding a sub panel. I can get a new 100 amp sub panel for $15. (I checked I can feed the subpanel with any amps upto 100, Hence If I want to get 60 I can do that without breaking code.)

I have already run 3 circuits in the garage. North wall, South wall and Ceiling. They terminate where the new sub panel will be located.

(at least for four months)
I would like to run another circuit for the MM175. Will the 10/2 be sufficient to run the garage. I figure at any given time Only a few lights, the radio and the Welder would be running at once.

I don't expect to be operating a grinder and power saw and welder at the same time.

My problem is Time and Money like everyone else. I already have everything I mentioned. But the feed to the garage is run in 1/2" pvc. I'll never be able to squeeze a 4 gauge wire in there. So I'll have to trench the back yard.

I'm not afraid of the labor but the cost will get me killed, that and telling the wife. I'm tearing out her roses.

I hope I explained it better. I know everyone wants more power. And I'm sure come spring I will run a new service to the garage for the 220V compresser I'm building. I just don't want to redo that preexisting connection for a few months.

Thanks for any replies
Heck thanks if anyone bothers to read my gibberish

[Sberry]

As David pointed out the 10/2 cannot run dual voltages. You need 10/3 with ground to do that and it may be marginal at best. You can feed a 100A panel with any wire,, say a number 6 as long as you put a 60A breaker in the main panel. You might be able to pull out the 10/2 and replace with 10/3 with ground as a temp measure but can only feed that with a 30 from the main. As long as you were not doing more than some lights it would work and usually you dont grind at the same time as welding. You could re-feed at a late date with bigger wire. You will need ground rod and seperate equipment grounding bar in new panel though and as long as you use only a 6 space panel you do not need a main breaker in the garage.

[aircraft]

Originally posted by Red90YJ
I don't expect to be operating a grinder and power saw and welder at the same time.

Always expect to operate at the same time and wire accordingly.

[lranch]

Well.........Everyone is correct on this, only suggestion left would be: If you plan upgrade later on, and the Furher is on your case, you might want to make a Good E-cord and tough it out till the stock splits. Throw up an outlet in house and let her rip. If you look in the right places you can power welder this way for about 30-100$ (just don't drag cord through roses.) I know what you are thinking about the dual voltage. Yes it will work but don't do it. Hope this helps.

[Franz]

Horizontan boring under the flower garden is always an option, and will usually save your life from an enraged rose grower.