Electrical Circuits

[lucky13]

I am having an Electrician friend of mine come over this weekend and fix a couple of circuits for me. I am thinking about having him drop in another circuit for a welder "to be named later". I guess what my question is, for a home garage, how many amps should I be running? I haven't talked to him about it yet but he's not a welder at all, so I thought I'd ask here first. I have 220v 30amp in the garage already, but the compressor is on that circuit. I know for sure that I want a dedicated circuit for the welder. Thanks

[Rodsmachineshop]

at least a 60 amp

[Tritium]

Depends on the welder. 60A is what I use for my PU205P but it has excess capacity.

Thurmond

[lucky13]

I haven't completely chosen the welder yet. Keep tossing around a couple of different models. Most likely wont go over 200 amps, but maybe up to 250. I'd like to have some room for growth for, just in case purposes. I don't like doing things over again. So i'd like to do it once and not worry about it. Thanks for the help guys

[kenwhite]

I haven't completely chosen the welder yet. Keep tossing around a couple of different models. Most likely wont go over 200 amps, but maybe up to 250. I'd like to have some room for growth for, just in case purposes. I don't like doing things over again. So i'd like to do it once and not worry about it. Thanks for the help guys

It really depends on the welder and its source voltage and current requirements. For 220-240 VAC single phase welders a 60A branch should be more than adequate.

[everlastsupport]

220vac 60AMPS, 50 will work fine too. But I would go 60. It will handle anything we have single phase.

[Brian Ski]

50-60 amps is sufficient. But for me I would go with a 100 amp sub panel. If you already have 30 amps for a compressor, another 30 for a welding, and a lighting circuit.

The other way I look at it... #6 copper is rated for 50 amps, to provide service for the garage. It is pretty expensive. If you go with #2 alum triplex in conduit it will cost about the same amount (probably cheaper) and the breaker box should be about the same amount. Run it past your electrician and see what he says.

BTW it also depends on the room you have in you main breaker box. You can't put a 100 sub panel breaker in a 100 amp main box. (or shouldn't) Also need to look at the distance between the 2. The wire gets expensive fast...

[lucky13]

50-60 amps is sufficient. But for me I would go with a 100 amp sub panel. If you already have 30 amps for a compressor, another 30 for a welding, and a lighting circuit.

The other way I look at it... #6 copper is rated for 50 amps, to provide service for the garage. It is pretty expensive. If you go with #2 alum triplex in conduit it will cost about the same amount (probably cheaper) and the breaker box should be about the same amount. Run it past your electrician and see what he says.

BTW it also depends on the room you have in you main breaker box. You can't put a 100 sub panel breaker in a 100 amp main box. (or shouldn't) Also need to look at the distance between the 2. The wire gets expensive fast...

The house has its own panel thats set just for the garage. I'm not too worried about room on the panel. But I will ask the electrician about it. And I totally agree about the wire getting expensive in a hurry!!! Thanks for the help

[lucky13]

And yeah it'll just be a single phase welder. I really don't forsee the need to build a battleship

[Brian Ski]

And yeah it'll just be a single phase welder. I really don't forsee the need to build a battleship

Yea... You will have to stick with single phase. They do not wire residences with 3 phase. You can get or make a 3 phase converter. I have one but I have heard they are not the best way to run a welder. A phase converter is better for items with a motor, like a drill press, or mill.

[lucky13]

Thats good to know. I will be getting a lathe and mill, but that is way later down the road

[Brian Ski]

Thats good to know. I will be getting a lathe and mill, but that is way later down the road

Search the net on how to build a phase converter... If you are fair with electronics it is pretty easy. You need a 3 phase motor, several capacitors, couple switches and a relay. I did mine right with a 220 plug on a cord, hard wired the motor to a metal enclosure and put a 220 3 phase receptacle on the box. That way I can plug in different things. Looks nice and works great.

BTW 3 phase stuff, used, is usually pretty cheap because nobody can run it.

[lucky13]

Thanks for the info! This got put on hold for the moment. Found out that I have to change out my panel. Apparently the Zinsco panels have caused many issues and house fires when the breakers refuse to trip (happened yesterday also!). So i'm gonna upgrade the main panel and sub panels ASAP. Going from a 125amp service to 200amp. Just gotta pay for parts as me and my buddy trade the labor ( I work on his 69 Firebird). We're gonna be running 6/3 wire and a 50 amp breaker for the welder.

[Rodsmachineshop]

Zinsco panels are bad news its from there bad set up for the breakers get loose on the shunt bars and short and breakers don't shut off . Sounds like your guy know his stuff do it rite the first time , then you don't have to do it over later its good you installing a new 200 amp box a lot safer

[Rodsmachineshop]

I have a 10HP Rotary Phase Converter at my machine shop since most my engine machine shop machines are 3 phase . lucked out i found my inverter on ebay used for 450 bucks . use to have 3 phase in my shop but the stupid power company disconnected it about 4 years ago when one of the transformer took a crap on the power pole . what a difference on the electric bill when you have 3 phase and switched to single phase ,, the electric company is such a rip off

[lucky13]

Yeah he is a good friend of mine and he would not steer me wrong. I've done some reading about the Zinsco panels and am not a fan!! Seems like they were used alot around this area. Just sucks that now I'm gonna have to save for a little bit longer to get a better welder

[Rodsmachineshop]

check on ebay i got my box's cheap they don't have to be new,, got good used siemens got both 200 amp load centers for under 150 bucks they even had some breakers in each box

[lucky13]

cool I'll look em up. Any brands to watch out for (Zinsco obviously)? On a side note I see you own a machine shop what kind? I work part time at a friends automotive machine shop.

[Rodsmachineshop]

zinsco is the only one i know of , but ask your friend since he will know what breakers are the cheapest and best , is your box outside or inside ask him what box you need , my both boxs i got was for outside , didn't mind since there just mount on my machine shop walls, Hey i didn't know you was in California . I grew up in Palm springs ca before moving to Parker AZ its next to Lake Havasu

[lucky13]

The main breaker is outside (also Zinsco) and the main sub-panel is in the garage. So far the plan is to gut the main breaker and replace all internals. Then drop in 200amp service and change out the entire main sub-panel. The panel upstairs is good still and so is the panel outside for the spa. Shouldn't take more than a few hours he says. Yup I'm a Cali/bay area boy for my entire life. Spent 28 years in Pacifica (5 min south of SF), and the last 3.5 in Antioch (50 miles east of SF). Rhats when me and the wife bought our house