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10/20/2017 1:01:18 AM
9/22/2017 12:11:25 AM
Posted: 6/18/2002 9:09:17 PM EDT
i just built a home workshop and i'm going to wire it next week, i will have a welder (50amp) plasma cutter in the future (around 50-60amp) air comp. recepticles, lights etc my question is: i need about 100feet of wire to supply the shop what guage would be sufficient for this distance and service? and i'm going to run off my existing meter because the electric company has some kind of scam about having more than one meter, a minimum monthly charge. what size breaker will work with room to grow in the future?
Link Posted: 6/18/2002 9:27:36 PM EDT
Link Posted: 6/18/2002 9:49:20 PM EDT
From what you're saying about the meter it sounds like you're talking about single phase. I would think that a 50amp welder would be three phase. First, if it is three phase then your house must be wired for three phase. Most houses i've seen are not wired for three phase.
Link Posted: 6/18/2002 10:13:54 PM EDT
3 phase electric supply is only used in commercial and industral applications... All residential electric is 110/220v 60hz single phase... You will NEVER see 3-phase electric in a residential environment unless you are running industrial equipment or 75+hp electric motors... If you have a 200amp box in the house, you can use a 100amp breaker to supply the garage...(feeding a smaller breaker box in the garage) Unless you plan on operating all your equipment at max output at the same time, you will be fine with a 100A supply... Most 250A DC welders will pull around 45-55Amps (220V) at max output... I don't have a electrical code book in front of me, but wire size will be determined by the equipment load/breaker size, length of wire, and conductor material (aluminum or copper)... I did my garage several years ago, and can't remember for sure what size wire I used... I sorta think it was 100ft of 2/0 gauge from a 100A breaker... I'm sure someone else can give you an exact wire size... Just my 2 cents...
Link Posted: 6/18/2002 10:31:05 PM EDT
I agree with ComputerHater_Art, a 100A service should suffice. Of course, that is assuming your main panel can handle the added load. If so, the minimum allowable conductor size for a 100A subpanel is 3 AWG (assuming THHN in conduit...for UF cable min. size is 1 AWG). But since your subpanel will be 100 ft away from your main panel, I'd use at least 1/0. If your air compressor draws more than 15-20 FLA, I'd go even bigger. And just a bit of advice, pull THHN through conduit, don't direct burry the cable.
Link Posted: 6/18/2002 10:58:07 PM EDT
I would figure a 120V,15A circuit for the lights. One circuit for the compressor(how big is it?) 120V, 20A for 1.5HP or less. At least one additional 120V, 20A circuit for everything else. You don't really need a huge service for a home workshop where there is one person working in it, just enough to supply everything that you will be using at the same time. 100'is kind of a long way, so I would do something like putting a 40A double pole breaker in the main box feeding a subpanel in the shop through #4 wire. Put breakers in the subpanel for the lights, compressor, and two general purpose circuits. Since the subpanel is close by, #12 wire will be fine for 20A circuits, #14 or #12 for 15A circuits.
Link Posted: 6/19/2002 2:12:11 AM EDT
I can help you. Need to know amperage rating of your existing panel in yor home. You would be looking for something that says perhaps 220/120 volt, 200 amp. Need to know electrical rating of the equipment you have. Your welder and/or air compressor should say something like 220VAC/100amp, 120VAC/200amp, 1PH. Need to know physical dimensions of your workshop. Is your workshop a separate building? Or is it attached to or an integral part of your home? Does your home have electric heating? electric hot water tank? electric clothes dryer? electric range? All these will diminish the power available for your workshop. Just for your information. You can get three phase service to your home. You will have to pay the utility company to have them set it up at the utility pole, but it may be worth it depending on how serious you are with this workshop. I used to know a guy who did this. This allowed him to purchase used industrial equipment. He had a drill press, a small lathe, a welder, a bunch of other stuff. Again, it depends on what are your plans for the future of this workshop are. Just don't get too excited about being able to use all your large equipment at the same time. Your loading may not allow this. Perhaps you may want to consider Ox/Ace. welding tanks.
Link Posted: 6/19/2002 5:56:14 AM EDT
i should have mentioned my home has 200 amp service, the compressor is small 1hp, welder is 220v/50amp (small lincoln welder) no plasma cutter yet but i will get one, the one we have at work is 80amp i'll be getting a smaller one about half the size, the shop is 30x30 100ft from house and my house is gas heated, i also forgot to mention i will put in a small a/c window unit i'm going to enclose a small area to reload in. 3phase is out of the question, $10,000 to run another phase down my line i may in the future produce my own 3phase, my dad has it in his shop i'm not sure how he does it but it has something to do with 3 motors thanks for all the help
Link Posted: 6/19/2002 7:01:16 AM EDT
Oops...when you said 50A welder, I thought you meant a little one that produced 50A, not one that sucked that much power. A subpanel fed by a 100A breaker through 1/0 wire is the way to go, as others have suggested. Another alternative may be to run a 50A circuit with #2 wire from the main panel just for the welder and plasma cutter(but not both at the same time!). Then use a 40A with #4 (or 50A with #2) for a subpanel for everything else. May be easier this way than dealing with that bigass 1/0 wire. If you have an electric stove/dryer/water heater, it may be a good idea to replaced those with gas units. It's a relatively cheap way to give you extra electrical capacity. If you use your shop alot, be prepared for the police to visit. I've heard of cases where search warrents have been issued due to excessive electricity usage, because they were using it for lights to grow pot.
Link Posted: 6/19/2002 7:12:32 AM EDT
50 amp is what the manufacturer says it has to have so i'm sure it will probably never draw that much especially in a home shop
Link Posted: 6/19/2002 7:27:09 AM EDT
I'm not an electrician, but 2 thoughts: 1: Make you you do not cut any corners, make sure what you do meets or exceeds all code & safety requirements. 2: Think about how high off the ground you will have the wire from the house, unless you are going underground,(which has its own issues). You may someday need to move something tall under the wire & it would be a pain to have to take it down or have someone fry like that newslady did.
Link Posted: 6/19/2002 7:41:49 AM EDT
[Last Edit: 6/19/2002 7:47:59 AM EDT by BlammO]
OK, based on your parameters, I'd say the biggest load you'll have would be the plasma/compressor combination, plus lights & misc. stuff. I'd recommend putting an 80A or 100A breaker in your main panel and running #4 (#2 is even better) for your two hot legs and #4 or #6 (one size smaller than the hots) for the neutral. On the subpanel in the shop, run a #8 wire (either bare or insulated) from your ground bar to a copper ground rod outside. Use #10 Romex from the subpanel to your outlets. You can use #12 Romex with 20A breakers, but in a shop, I tend toward a little heavier wire. I'm fond of twistlock outlets & connectors for the heavy 220V stuff, but those get expensive in a hurry. I wouldn't recommend doing any of this if your main panel is a 60A service. 200A service is best (common for newer homes). If you have access to a clamp meter, it's very nice to be able to turn on all your appliances and measure the load on your mains. That will give you an idea of how much capacity you have to play with. Here's something else you might want to consider; install a second meter in your shop before the subpanel. It's nice to know how much of your total electric bill is consumed by the shop. You can get meters cheap on eBay. Mount it inside, away from the main meter so you don't create confusion with the electric company. 50A double-pole breaker is pretty standard for a 220V arc welder. I've run a 230A (output) welder at nearly full output on a 30-amp double breaker without tripping it, but I wouldn't recommend that for safety reasons.
Link Posted: 6/19/2002 8:01:51 AM EDT
From what you're saying about the meter it sounds like you're talking about single phase. I would think that a 50amp welder would be three phase. First, if it is three phase then your house must be wired for three phase. Most houses i've seen are not wired for three phase.
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I don't think you will see this anywhere in the US not becuase you may not have the equiptment but it's most likely against every zoning ordinance in the US. Ben
Link Posted: 6/19/2002 10:52:24 AM EDT
you've all pretty much answered my questions thanks for the help!
Link Posted: 6/19/2002 9:27:30 PM EDT
I know the thread has probably run its course, but here are a few bits of useful info for ya: For service entrance, #4 copper wire is good up to 70 amps. #2 is good for 95 and 2/0 will carry 175 amps. You can also use 2-2-2 aluminum up to 100 amps. It has all the conductors you need in one jacket, but it's really bulky. The neutral can be one size smaller than the hots. I'm unaware of any zoning codes that prohibit residential 3-phase, but it is rare. In many areas, you can have it if you 1) have the bucks to pay for getting it to your house, and 2) your electric company is willing to do it. 3-phase usually isn't a problem in rural & semi-rural areas. Generally, you gotta have a lot of *really* heavy duty equipment in your shop to warrant 3-phase. But then, you weren't really asking about that . . . [:)]
Link Posted: 6/19/2002 10:05:23 PM EDT
[Last Edit: 6/19/2002 10:08:06 PM EDT by Naked80]
Originally Posted By thebeekeeper1: I have grown frightened, BTW, of hearing licensed electricians say, "We just . . ." I am doing the job [b]right[/b], and per NEC (National Electrical Code). No cutting corners. Like you. [shock]
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Some electricians complain because they have to unfortunately DEAL with Mr. Handy/Maintenance man. [shock] I have seen some REALLY scary S%^& that I had to pretend I didn't. 100 amp panels fed with Green #10s, free air 480v 3 phase wires, lack of grounds.....huge differences in potential, and energized equipment that isn't supposed to be! 14.4 KV High Voltage wires Live underwater, coiled on the floor of manholes and not racked per NEC code.[soapbox] BTW-You can get 3 phase power if you're tricky. [}:)]
Link Posted: 6/19/2002 10:12:54 PM EDT
Originally Posted By sr15: And just a bit of advice, pull THHN through conduit, don't direct bury the cable.
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Underground Feed cable can be a friggin' nightmare. Go with conduit.
Link Posted: 6/19/2002 10:54:20 PM EDT
Originally Posted By BlammO: I know the thread has probably run its course, but here are a few bits of useful info for ya: For service entrance, #4 copper wire is good up to 70 amps. #2 is good for 95 and 2/0 will carry 175 amps. You can also use 2-2-2 aluminum up to 100 amps. It has all the conductors you need in one jacket, but it's really bulky. The neutral can be one size smaller than the hots.
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Yes, but I'd go up one size for long runs like 100' to reduce voltage drop and heating, especially if it's run in conduit and not in the open air. For 100' with less than 2% voltage drop, use #4 up to 45A, #2 up to 70A, and #1/0 for 100A Naked80 - When I found #14 wire fused at 30A and splices made by loosly twisting wires together without wire nuts or even electrical tape, I knew it was time to rip the whole mess out of my house and replace it.
Link Posted: 6/19/2002 11:31:43 PM EDT
Originally Posted By MadMatt: Naked80 - When I found #14 wire fused at 30A and splices made by loosly twisting wires together without wire nuts or even electrical tape, I knew it was time to rip the whole mess out of my house and replace it.
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FWIW For an efficient operating system voltage drop should not exceed 3%. Last month my sister's fiance was having power problems. After 20 minutes of removing S%^& from in front of the fuse panel, I found ALL of the #14 gauge wires to have either 20 or 30 amp fuses in them. The wire WILL burn up before the fuse will trip. It always is a really big funny if you ask the homeowner, "has this one ever blown?"[}:D] when refering to the over sized fuses. [b]If you have old house you might want to have your service upgraded, or at least looked at to see if the previous owners are trying to KILL you.[/b][shock][flame][pyro]
Link Posted: 6/20/2002 2:01:32 AM EDT
If you need three-phase at some point, ask over on USENET in rec.crafts.metalworking . The home shop machinists there will be able to tell you exactly how to do it.
Link Posted: 6/20/2002 2:47:34 AM EDT
Originally Posted By ComputerHater_Art: 3 phase electric supply is only used in commercial and industral applications... All residential electric is 110/220v 60hz single phase...
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True but we've had power companies here offer a price break for people who wanted 3-phase in their homes for Washers and Dryers. I know a guy who has his laundry room wired for 3-phase and i've met others who have had 3-phase air conditioners in their homes. Not common thats true! They offer price breaks because they don't have to have the transformers needed to drop one leg of three phase (277v) to 110-120v single phase.
Link Posted: 6/20/2002 2:57:03 AM EDT
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