Increasing Electricity into your home question

I have a 150amp panel in my home, which is decently full, but probably has space for about another 70amps worth of breakers, but only about 4
spots left.
I HAD planned on running a 70 amp breaker, and then 4 gauge wire to my garage to a new breaker panel. That will probably max out my panel in my house. I've done all of the math, and I'm pretty sure it can handle that.
One of the reasons I am doing this is to run some 230V tools in my garage. Now recently, I may have come across the opportunity to get a used cheap Millermatic 250 Welder, which is going to pull 44-45 amps vs the original 20 amps, I was going to pull with a smaller Welder. This welder all by itself would require a 60 or 70 amp breaker. So now, I would like to run 100 amps to my garage instead.
Because of this, I'm thinking I need to increase my House Panel from 150amps to 200amps. What all is involved in this? Does the electrical company usually do this for free? I know I will need to buy a bigger main breaker, will there be anymore cost involved?
Is 4 gauge NM-B still ok for 100 amps, or is it pushing it too much? Pushing that much through it, does that present a fire risk, or is 4 still enough? That kind of distance should be a 2% or less drop, which is ok, just curious about heat.
This will be through my Basement Ceiling Joists, then up a Garage finished wall, then through the Garage Attic, then to a Breaker Panel. Should be about 70-80 feet.
Thanks, James
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At the *VERY* least, you're going to need a new main breaker. Beyond that, well... You've heard that old line "The sky's the limit"?
Your first step is finding out what the power company has you hooked up as. If you're on a 150 amp feedline, then without a service change, that's your ceiling - Period. If you're wired as a 200 amp or higher service (fairly common, but NOT universal) the power company won't need to be involved - Just the panel/inside wiring changes that might be required. Otherwise, you'll need a new service drop of the right capacity, and that's going to run into medium-to-large dollars.

Are you out of your everluvin' skull???
I want to try some of whatever it is you're smoking to get yourself *THAT* stoned! :)
Expect to be charged if they need to change out or rewire your pole-pig and/or change your drop line - Wouldn't surprise me if they charged it the same as a completely new installation, all the while telling you what amounts to "Poor planning isn't our problem. You should have thought of that when you had the service installed in the first place". And grinning all the way to the bank, of course.
Also expect to need city/county/state/whatever's applicable permits, and a demand from the local powers that be that the work be done by a licensed electrician, then inspected the same as when the initial hookup was made - each one wanting their piece of the pie, of course.

I imagine the breaker will be the smallest cost involved, with plenty more piled on top of it. Sucks, but that's pretty much reality if you want it done (A) right (B) legally, and (C) insurably.
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Here's my 2 cents FWIW:
How often are you going to be welding at full amperage? I would gues very infrequently... so you will very rarely pull that kind of current. Also, welding is an intermittent load... so, you can get away with less current capacity, cause you aren't running continuously. And, anyways, 70A is plenty... you're not planning on welding at full current while running a big lathe taking a .500" DOC, with a load of wash in the W/D, the electric stove boiling spaghetti on every burner, and every light in the house on, right? I'd suggest work with what you got if you can't up your service easily. Get to buildin'!
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That's pretty much what my power company told me when I told them 200 amps wasn't enough.
I have 2 edms 1 cnc lathe 3 cnc mills air conditioned shop (over 5 tons) large air compressor to run the place And multiple manual machines and welders.
They said to contact them when I noticed power problems....It's been 5 years, and I still haven't had to call them.
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I ran my whole shop on a 70 amp breaker,2 phase convertors, 2 cnc knee mills, 5 hp lathe, 2hp tumbler, 5 hp fully auto cold saw, saws, drill presses, compressor, 1200 watts of light. Did occasionally pop the breaker. That is with 2 cncs running, the FA saw and compressor going and the tumbler going
What I would have done different, which I don't see mentioned: much bigger feed wire ga. try a 1/0 instead of 4 ga, you will be happier.
The power company replaced the wire from the pole to the house because the other side of the 2 family the lights blinked when I powered up a machine.
I now run my shop on a 175 amp breaker, 3phase, with 3 cnc mills, much bigger compressor, tig welder, 80 kva VMC, 3 tumblers an tons more lights.
400 amps is nuts
Dave Lyon wrote:

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I'm not familiar with 1/0 or 2/0 wire. I guess that is just a thick copper wire shielded. So I would need 3 of those to run Hot, Hot, Neutral wire? Plus I would need a ground wire? How does that compare price wise? Also, what is the best way to wrap them together, and do you have to run it through condiut?
Also, the Millermatic 250, that I was trying to buy, fell through, so I won't have anything that big now. I know I would never need anything bigger than a Millermatic 210, but saw the 250 for a good price and that fell through.
I just bought a Hobart Handler 180 reconditioned welder off Ebay today for cheap, so will be using that for a long time. That is rated for 20 amps, and something like a Millermatic 210 or Hobart IronMan 210 are rated at 25 - 27 amps. So now I know I won't ever need a 45 amp welder, 25 - 27 amps max. Also the more I think about it, I will never be using the Air Compressor and Welder at the same time. So I'm sure I could take my Air Compressor off the list, math wise.
I think this may be good enough for the math
Welder, Tools Outlet, Outdoor Lights. What do these Welders draw usually just being turned on and not used? Just incase I have it on, and am running saws or grindings at the same time.
I'm starting to think now, I could easily run 6 ga wire and a 50-60 amp breaker and be just fine. Any opinions on that? I can get 6 ga wire pretty easy and cheap in my area. I can get that as low as $1.10 / foot, where I got quoted $2.46 / foot for 4 gauge. I may still run the 4 ga though to be safe. Would cost me about $100 or so more to run, but might save me in the future, if I don't need to up the amperage.
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    That's where you wind up after going through the normal wire gauge sizes -- from say 22 or 18 ga (zip cord), 16, 14, 12, 10, 8, 6, 4 and 2, you then hit 0 (which is also called 1/0), then 2/0, 3/0, and 4/0. That last size is about the diameter of my middle finger, exclusive of the insulation. There are smaller and larger wires, but these are the ones which I have worked with.
    Suffice it to say that 2/0 is capable of carrying eight to sixteen times the current of the wire sizes which you mentioned in the part which I trimmed below.

    You mean "insulated"? Shielded requires a layer of insulation one or more layers of electrical braid or foil, and another layer of insulation, and shielding is uncommon on power wiring -- more for low level signal wiring to keep electrical noise out.
    Good Luck,         DoN.
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Sounds a whole lot like what I went through a few years ago. I bought a house which had a large 2-car garage below, and planned to use that full-time as my shop. All good except there was very little wiring down there. There was a 220A connection for an electric hot water heater which wasn't used, so I cobbled up a long extension cord and just used my machines one at a time. My house at that time had a 200 amp service which was absolutely maxed.
After about a year we did a significant addition which doubled my shop space. I decided to deal with my power issue properly. I had to start by finding out what was available from my power company. I discovered that 400A services (what I wanted) are only granted sparingly. I managed to get them to agree, then I had to get hold of the local electrical inspector and ask him what I'd have to do. He said I could put in a 400A service which split to two 200A panels, one to my existing panel, and I could pull the other 200A down to a subpanel in my shop, but I would have to have a disconnect outside at the service entrance so the firemen could shut off the power if they had to. You don't have to do this if the panel is right inside the back door, but if the panel is down through to the basement, you gotta have it. The meter box (Square D) cost me about $600 wholesale on my electrician buddy's account, another $200 for the adapter it needed (it was set up for buried power feed and ours is overhead). Then about another $2800 in electrical labor and parts and I had a nice Square D 200A panel in my shop.
In my shop, I have a bunch of machines, some 220 single phase, some 220 3-phase running through a phase converter, and some 110 single phase. Included are 2 welders (one a Millermatic 250) which should by rights have a 60A 220V plug. They are wired into a 40A circuit, one or the other (never both) and are never used at anything like full amperage. My philosophy is this is a one-man shop, so I can run my 30A three-phase power all over the place and as long as I only turn on one machine at a time nothing bad happens.
You can't realistically do a major electrical move like this without getting a permit. Think about what happens if something in your shop starts a fire which does a lot of damage, and the insurance company were to find out you had major unpermitted uninspected wiring. They could legally refuse to pay. Unless you're as crazy as friends of mine who own large houses and drive cars without insurance, you won't go there. So I suggest you do what I did and start by calling your local building department and talking to the electrical inspector, then call your power company. What they say is what you will have to pay for. It's simple, but not cheap.
GWE
sparty wrote:

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I have seen something you have posted earler

I have a few questions, and comments. Any one who don't agree feel free to set me strait. First thing the new welder will only use 47 amps when you turn it up all the way. Not that you would not want to use it cranked up all the way, but when you do you can always turn the compressor off. the next thing you have shown, but was not clear was the 120v loads. The loads could be put on opposite phases so the load will not be 40 amps when you have 20 Amps on the black phase and 20 amps on the red phase it will be 20 amps. How many horse power compressor do you have if you take the horsepower and multuply it by 746 that will give you the ammount of watts. Just because you use a 20 amp breaker that doesn't mean that the circuit will automatically draw 20 amps it just means that the wire that runs to the load is protected at 20 amps. And on the outside lights you would have to have alot of lights burning to equal 2400 watts. If you take the ammount of watts off the bulbs you plan to use that will help your equation out alot. I am not wanting you to change your mind, just giving some food for thought before you spend three thousand dollars on electrical instead of more metal working equipment. PLE
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Service upgrades don't cost anything here unless you go underground. The utility doesn't always change the drop anyway. Electricians like to be paid, however. The electrician has to do everything beyond the service drop from the pole.
I know I will need to buy a bigger

Unless your existing panel is UL rated for a 200 amp breaker you will be buying a new panel, which will come with a breaker. You might as well get the new panel, which will have more spaces.

I think you'll be fine with your 70 amp subpanel. Install it and take some current readings before you change your whole service. You'll probably be surprised how little you're drawing.
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Depends on where you live. In North Carolina the property owner can do their own electrical work. Still has to be permitted, inspected and meet code but an electrician isn't required.
Steve. Who is currently installing a 200A panel and all the wiring in my new shop.
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I didn't mean to imply that a licensed electrician is required. Very few homeowners are up to the task of bugnutting the live service drop, which is part of the job here since the utility's responsibility ends at the drop.
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I can easily run wires and hook them up no problem. Just for kicks though, I'm going to call the city and ask them if I can take a test or something along that to do my own electricity and get it inspected. I know someone where I used to live in TX, that called and they let him take a test and get a temporary license to do his own.
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Irving, TX, where I live, just requires you have a permit and have it pass inspection. The inspector I dealt with told me he would help in any way but would not pull wire. If I had a question he answered it. When I was finished it was to code. He also told me of shortcuts to save money. When I asked about brands of breakers he said he couldn't recommend any brand BUT brand x would not trip as fast as brand y. (Drag test of a live wire to ground, x would let the wire weld before opening. Y opened as soon as it touched, my choice).
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On Sat, 11 Feb 2006 00:49:50 +0000, Clif Holland top-posted:

Sounds like a right neighborly fellow! :-) Was he charging by the hour? ;-)
Cheers! Rich
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Nope, once I paid for the permit he was the inspector, no additional charge. As you can figure out a super nice guy.
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wrote:

The chap who inspected my last house when I re-wired it, noticed that I had not installed a gasket where the overhead service stack (scepter aka plastic conduit) connected to the meter box, provided the required cork gasket and showed me how to instal it without pulling the wire out - just unbolt the flange, break the gasket on one side and slide it into place. Later he noted that I had grounded the copper drain from the kitchen sink and commented that this was not required by code but was such a good idea that he intended to do the same in his own home so I paid him back for the gasket with the proper ground clamp salvaged from work. I never had any problem with inspectors even though they always knew that I was not licensed, but had been working at the trade part time since 1948. The city building inspector, on the other hand, just about blew a fuse when he discovered my lack of license,however, the house had been passed and the service connected. His only recouse was to tell me not to wire any more houses in his territory, so we built the next house in a neighbouring village. His main concern was that he wanted to sell me a city business licence and couldn't do it without a journeyman ticket. Gerry :-)} London, Canada
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The Local Electric is usually responsible up to the meter base. You might be able to contact them regarding the transformer capability, how many homes are connected with yours, etc. The last time I counted, I had 1800 amps of breakers on a 225 amp main. It doesn't matter how many breakers or feeds you might have but how much you turn on at one time. You might want to make sure the electric oven is off when the welder is running. You should be OK. Respectfully, Ron Moore

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See interlinear comments. I upgraded my house from 60A service to 350A service. I'm not an electrician so I had to do a *lot* of research. Was able after some self education (bought and studied a copy of the NEC) to get a city permit and do it safely myself. The inspector was impressed, so I must have done at least a decent job. =) See comments interlinear.

I ended up completely redoing the service to my house. Put in twin 200 Amp panels to match the large twin lug meter, swapped a 150 into the panel for the house for a total of 350 amps.

In Omaha at least the power company is required by the city to provide service on their end (appropriately sized transformer, meter socket, meter, wire from the pole to my wires protruding from the mast thru the roof) at no charge. Before I started the project, I called the power company and got in touch with the service designer over my area. He was pretty helpful. Didn't hurt that I sounded motivated to do whatever my part was and not be a nuisance. My neighborhood was built in the late sixties. He came out and looked things over. Said they would have to upgrade the current transformer that runs the block. Turns out they dug a new hole in my yard, installed my own utility pole and hung a commercial sized transformer just for my house. The old can stayed one house over and runs everyone up the block from me while mine now runs everyone from my house down. It seems they didn't want the block to brown out when I cranked things up. =) I'm tapped directly off the big can.

You need to make sure the existing panel is rated for the bigger breaker. For me to replace the 200A breaker with a 150 in one of my panels it was actually cheaper to buy another main breaker panel kit with the same style breaker and use the one it came with.
I realize you are talking a much simpler project, but for mine the basic order was something like this: -call the power company to make sure the project was doable and glean what I could in the way of their special requirements -get the city permit -power company issued me a new meter socket, no charge -power co sends a team to install "my" new utility pole in preparation for my upgrade, also no charge -install a complete overhead service about 20' from my old one to place the new panels directly in the garage -install new monster grounding rod system sized for the new service. Interestingly enough the conductor running just to the ground rods is bigger than the old main service lines -convert my old panel into a subpanel (just separating neutral from ground, had to install another ground bus) -install a single breaker to feed the old house subpanel from the new house panel -wire everything literally just short of connecting the new panel to the old main breaker. I ran the wires all the way and taped the ends to avoid fireworks before the power company came out to shut off the old and transfer to the new transformer -make sure everything is perfect, then have the inspector out to have his look -inform the power co that the inspection is complete and approved -schedule a day for them to come do the switch -wait around most of the day for them to come =) -power co. crew arrives and kills power to the block -with a flashlight i do the final hookup inside between new panel and (old, now sub)panel -give the crew the thumbs up that I'm done and everything is squared away inside. ie: no shorts. =) -line outside goes live -check voltages inside before throwin' the switch -done. From tabulated resistance values, I calculated that at full 350A load the aluminum wiring between the house and pole becomes an approx. 1000 watt strip heater. The power company does not have to obey NEC for distribution lines. Even so, the voltage drop at that load should be less than 4 volts. Better than the guys at the far end of the block get even at low loading.
The only cost to me was for the permit and inspection, the hardware and wire inside the house and some of the stuff outside the house. I bought and own the mast and the copper wire inside. The meter socket is now an integral part of my house and they tell me it is mine to keep. The meter itself and the wire going from my mast to the transformer at the corner of the yard are owned by the power company, provided at no cost to me.

There are so many tables for the various insulation/environment combinations it takes me a bit to find the right one. Hopefully someone will chime in with an expert tip.

hth,
StaticsJason
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Personally, I would just upgrade the entrance service (meter base) to a 400 Amp unit with a 350A disconnect and split between the existing 150 Amp service and a new 200 amp box in the basement. This will cover any future additions (lathe/mill/surface grinder/other cool tools) you may do also.
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