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Drott-150

How many amps does your shop need?

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I'm going to build a pretty big workshop on my lot (about 45' x 85') including a living space inside and plan on having a decent array of welders and machine tools along with normal things associated with a home - i.e. HVAC and possibly electric heat for the living area (about 1500 sqft), washer/dryer (all electric), general lighting, and maybe a Jacuzzi in the future. The large shop space will be heated with wood and or oil (no AC), so that shouldn't be factored.

Any ideas what level of service I should get (amperage wise)? They offer 200-350 amp service at a standard rate. Anything over 400 amps requires a load letter and a riser diagram (whatever those are) from an electrician. But apparently if I have the letter and diagram I can get 400 amps and over for no extra charge...if I properly understood the field rep yesterday anyway.

I need to decide here real soon, and as always big $$$ are at stake, so any advice from you experts would be real helpful. Thanks in advance!

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I work in the construction industry commercial and some residential, and this is my recommendation but by no means am I an electrician or electrical engineer. Typically a 200 amp service will run a normal household and a descent sized garage. This gives you ample power to run all major appliances, and have 100 amps dedicated to the garage with one 220 plug in the garage. You mentioned multiple welders...I get the impression you are looking at a mini machine shop. In this case you are talking at least the 350 amp service. Just my opinion...trying to help. It's always better to have more than you need than not enough.

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How long do you plan on working in this shop? Is three

phase available? In the long run 3 phase is cheaper, so I have been told.

Keep in mind I now nothing about electricity, but I am from the school of

thought that you over build now because at some point in time you will use

those resources later. Really depends on what your short/long term goals

are. Are you going to be doing any of the work yourself? Are you going to

start up a buisness at this location?

This topic will probably be a hot one & may give you

more questions than answers!

Good Luck!!!

Gilligan

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200 amps is plenty. 100 will work if you don't run the big energy

hogs at the same time ie. not welding while the wife is in the

hot tub. BTW I had one of those big tubs it could blow a 50 amp

breaker with all the pumps and heaters running, Just a big waste

of electricity and water.

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Thanks for all the advice so far, let me clarify a few of the questions brought up. I don't plan on having a business per se, but I do envision having a pretty well outfitted machine shop. I plan on having a nice arc welder (Mig/Tig/SMAW) capable of light and heavy welding, a lathe, milling machine (or two), shaper, grinder, bandsaw, drill press, and maybe a few other powered tools as the need arises. But for the most part I'll be working by myself, I won't have "employees" or anything, so it would be rare for more than one machine to be running at the same time. Although there may be times when someone is helping me, or that I might be running an automated CNC process on a mill while I work at another machine. Or maybe have something in a sintering oven while I work at another machine. So I suppose there are situations that could arise where a few machines are running simultaneously, but certainly not all at once as might occur in a commercial application.

Thanks so much for the help, I'm in "I'm my own general contractor rapid decision mode" right now!

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One thing you might do is add up the biggest items that will be running simultainously. That might include the "residence" if you are willing to work through dinner. :D

mike

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AM TRING TO GET AHOLD OF DAD(ELECT.DESIGNER-COMMERCIAL) TO TRY TO FIND OUT WHAT HE THINKS.

UNTILL THEN

WITH THE POS. OF ELECTRIC HEAT I WOULD THINK 200 AMP IS PUSHING IT. DAD HAD OIL HEAT AND REPLACED WITH HEAT PUMP WITH ELECTRIC BACK UP AND HAD TO HAVE SERVICE UPGRADED TO 200 AMP. HE USES NO GARAGE TYPE EQUIPMENT JUST HOUSEHOLD LOAD. SO FOR THE TIME BEING I WOULD THINK MINIMUM OF 350 AMP.BUT ON THE OTHER HAND THE POWER TO MILKBARN IS ON 50 AMP BREAKER AND I HAVE NOT BLOWN IT, YET! HAVE A LARGE FREEZER,7HP.60GAL.COMPRESSOR,MILLER 120/240 WIRE FEED,225 LINCOLN,BUT IF A WELDER IS ON I TURN THE COMPRESSOR OFF, IF I NEED AIR AT SAME TIME I HOOK UP 5HP 220COMPRESSOR TO AIR LINE TO KEEP PRESSURE IN BIG COMP. UP.THE 7HP TAKES 52AMP FOR START UP BUT IT WILL START AND RUN WITH 30 AMP SLOW BLOW FUSES FOR SHOP MOTORS AND HEATING SYSTEMS WITH OUT BLOWING FUSES.

I ALSO AM NOT AN ELECTRICANN OR AN ELECT. DESIGNER OR ANY OTHER QUALIFING OCCUPATION,I HAVE DONE A FAIR AMOUNT OF ELECTRICAL WIRING AND DID SPEND ABOUT 6 MONTHS WORKING AS ELECTRICANS HELPER BACK IN LATE 70'S MAINLY COMMERCIAL(WHY I PREFER CONDUIT OVER HOUSE WIRE).

THIS 20 YR OLD MODULAR HAS 200 AMP PANEL 90AMPS FOR FURANACE,40 AMP FOR STOVE,30AMP DRYER,25AMP HOT WATER,PLUS LIGHT AND OUTLETS, WASHER AND 2 KITCHEN OUTLETS ARE 20 AMP REST AND LIGHTING ARE 15 AMP.

LOAD LETTER IF I UNDERSTAND DAD RIGHT SOUNDS LIKE LETTER STATING AMP DRAW OF ALL EQUIPMENT TAKEN FROM ALL EQUIP./MOTOR TAGS,AND FIGURING X WATTS OF LIGHTING TO X SQ FEET AND OUTLET WIRING,ETC.BASICLY NEED DESIGNER/ELECTRICAN TO DETERMINE TOTAL LOAD DRAW YOU WILL NEED FOR YOUR BUILDING,RISER DIAGRAM SHOWS SERVICE ENTRANCE AND ALL PANELS CONNECTED TO IT,AS I UNDERSTOOD DAD.SUGESTION WAS YOU NEED AN ELECTRICAL CODE BOOK (IF YOU CAN UNDERSTAND AND FIND WHAT YOU NEED IN IT (CAN BE COMPICATED TO THE UNKNOWING-FROM MY EXPERIANCE TO UNDERSTAND/INTERPITE)OR NEED TO CONSULATE ELECTRICAN,SUGGESTS THAT 350 AMP OR 150 AMP PANEL MIGHT BE HARD TO COME BY BUT MIGHT BE ABLE TO CHANGE MAIN BREAKER TO 150 AMP/350AMP(IF EXISTS-HE DON'T RECALL AND MY CODE BOOK IS NOT AT MY FINGER TIPS CURRENTLY)IF CODE/POWER SUPPLIER ALLOWS IT-MORE QUESTIONS NOW TO FIND OUT.

I THINK YOU JUST OPENED A CAN OF WORMS,GOOD LUCK, WILL TRY TO FIND SOME OF THIS IN CODE BOOK AS SOON AS I CAN GET TO IT,HOPEFULLY WE HAVE AN ELECTRICAN ON HERE SOMEWHERE THAT CAN GIVE YOU BETTER ANSWERS.DAD HAS A LOT OF THINGS GOING ON THE NEXT FEW DAYS AND IS NOT ABLE TO GET ON COMPUTER FOR AWHILE,PLUS HE NEEDS TO JOIN RP FIRST.

TAKE CARE,HAVE A GOOD ONE BEST OF LUCK,!

PAUL

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I have basically a similar setup for power needs, lathe, 3 welders, grinder, plasma, big compressor, mill with another on the way, electric washer/dryer, all electric kitchen plus the entire house. I have a 200 amp service and it is more than enough.

My basement shop is wired on a 20 amp circuit for the outlets, the lathe, compressor and milling machines are on a 30 amp circuit and the welders are on a 60 amp circuit. I have NEVER popped a breaker in 25 years and I don't make a habit of running more than what a circuit can handle. I have never worried about running shop equipment while anything else in the house was being used.

You will be just fine with a 200 amp service. Put the money you will be saving by not going to 350 amps (it's overkill and have you priced out a 350 amp box? big $$$) into another shop machine. :rolleyes:

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I have 400 amps in my barn/shop with an apartment over it. I have a 2.5 ton heat pump, 7 hp compressor, 5 hp tablesaw, 15" planer, 8" jointer, mig welder, stickwelder, dust collector, two fridges, instant elec water heater (3 - 50 amp circuits for that). The compressor will dim the lights in the apartment when it comes on. I tried to get 3 phase installed, but I had to prove a 15HP min load to the power co. If you intend to run any decent machine tools you should try to get 3 phase. You need to look at phase converters both as to price and HP capacity. Factor the cost of the converter against the cost of 3 phase installation. You can get some really cool big old machine tools that are 3 phase reasonably cheap. The 220 stuff is smaller and more expensive to buy and run. Just my two cents, but its always cheaper and better to put in adequate service up front than to go back in a couple of years and try to upgrade.

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I'm gonna agree with Rawleigh99, if you can, get 3 phase. Especially if you plan on running lathes or vertical mills. We built a similar shed alittle over a year ago(50x80). We ran 220 single phase to it with 200 amps. But less than a year after I had the shed wired up we wished we would have ran 3 phase to it. The main reason we didn't was because it would have cost $3per foot, thus it would cost over $1500 to get 3 phase to the shed. It seems cheap now. You'll be suprised how many things you'll find that are 3 phase.

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You need to look at phase converters both as to price and HP capacity. Factor the cost of the converter against the cost of 3 phase installation. You can get some really cool big old machine tools that are 3 phase reasonably cheap. The 220 stuff is smaller and more expensive to buy and run. Just my two cents, but its always cheaper and better to put in adequate service up front than to go back in a couple of years and try to upgrade.

QUESTION HOW MUCH ELECTRICITY DOES IT TAKE TO RUN PHASE CONVERTOR?

SOMEONE ONCE TOLD ME THEY ARE POWER HOGS, DON'T REMEMBER WHO OR KNOW WHERE THEY GOT THEIR INFO.

AGREE ON BETTER TO BE OVER THAN HAVE TO REDO LATER,BUT RESONABLE AMOUNT,NOT OVER KILL,SOUNDS LIKE COULD GET BY WITH 300 OR 350 AMP.400 AMP WITH REQUIRED ITEMS MIGHT GET COSTLY JUST TO GET POWER CO. TO APPROVE IT,WOULD REQUIRE RESEARCH TO DETERMINE LOAD NEEDEDAND WOULD PROBABLY WOULD NOT BE ABLE TO GET 400 AMP WITH OUT LOT OF EXPLAINING AS TO WHAT ALL THIS EQUIPMENT WAS ABOUT IF NOT A COMMERCIAL USE.I KNOW OF ONE CASE IN WA. THAT PERSON GOT HASSELED BY INSPECTOR BECAUSE OF SERVICE AND WIRING HE PUT IN HIS LARGE 2&1/2 CAR+BOAT GARAGE.

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200 amps should be enough for all of the equipment. I agree with others that three phase power would be desirable for machine tools. The EMC we buy from has a much higher minimum charge for a 3-phase service; something on the order of $60 per month plus a hefty installation charge, and that's only if the additional 2 phases are available at your location. You should definitely consider radiant heat in the slab for the shop area. Remember that you only need enough power for all of the equipment that you plan to operate at one time. For shops, it's not uncommon to have a load factor of less than 20% since there are a lot of circuits, but only a few are in operation at any one time. I use my backup generator for three phase loads, since it is 3-phase and i only need 3-phase power for a welding machine. Keep us posted on progress!

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I agree with the radiant heat in the slab. I don't have it but wished I did. I convinced my friend to put it in his shop and he loves it.

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I have heard bad things about phase converters. They will get you by in a pinch, but they also decrease the life of your equipment. I know of a few welders that have burnt up because they were hooked up with a phase converter. Not right away, but over a few years they start by not working to full potential and having quirky problems you wouldn't normally experience and then the smoke rolls out of the machine and it's junk. Just my two cents.

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"I use my backup generator for three phase loads, since it is 3-phase and i only need 3-phase power for a welding machine. "

Good idea here. The generator needs to be run on occasion anyways and you need a backup generator so why not take care of your 3phase needs that way?

I would go for the full 350. The larger wire will create less voltage drop during the typical light loads and more is better for future stuff. It really comes down to additional cost for going from 200 to 350 amp service though and there is a point where it won't be worth it.

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When I built my shop (32x52) the power company gave me the option of converting to a 400 amp service with 1 meter at the house and splitting 200 for house and 200 for garage or going with a separate meter for 200 amps at the garage. At the time we were renting a basement apartment and shared the house bill with the tennant and I didn't want them to have to pay for shop stuff so I went with the separate meter. I also thought I might do some "for profit" stuff out there and would then be able to deduct the electric cost. What I didn't realize at the time was that "general electricity" costs more than "residential electricity" and I have to pay a minimum monthly charge on 2 meters instead of 1. So, I'm paying about 300$/year for the priviledge of having that separate meter. We no longer rent the apartment and eventually I'll get around to converting to the 400 panel on the house with a garage feed going from there. It is little details like this that drive me crazy. Like them charging 7$/month for one of those street lights when you can buy one for 75$ and run it for pennies/month. Another related thing to watch out for is if you are considering propane. A lot of the gas supply companies charge a flat minimum fee equivilant to 1 tankful whether you use that much or not. The company I started with did not, but they got bought out and the new company did. I heat with wood now.

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yellowrosefarm

"At the time we were renting a basement apartment and shared the house bill with the tennant and I didn't want them to have to pay for shop stuff so I went with the separate meter."

RUNNING THE MAIN-SUBPANEL SETUP THERE ARE NOW METERS THAT YOU CAN BUY TO MONITOR POWER THAT THE SUB PANEL USES.THEY ARE NOT LIKE YOUR POWER CO. METER DIGITAL AND MUCH SMALLER

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That's great to know about the sub panel meter. I hope I don't ever have a need for it though. We rented that apartment for 12 years and while most folks who lived there were nice, not having strangers coming and going is a lot nicer.

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I'm going to build a pretty big workshop on my lot (about 45' x 85') including a living space inside and plan on having a decent array of welders and machine tools along with normal things associated with a home - i.e. HVAC and possibly electric heat for the living area (about 1500 sqft), washer/dryer (all electric), general lighting, and maybe a Jacuzzi in the future. The large shop space will be heated with wood and or oil (no AC), so that shouldn't be factored.

Any ideas what level of service I should get (amperage wise)? They offer 200-350 amp service at a standard rate. Anything over 400 amps requires a load letter and a riser diagram (whatever those are) from an electrician. But apparently if I have the letter and diagram I can get 400 amps and over for no extra charge...if I properly understood the field rep yesterday anyway.

I need to decide here real soon, and as always big $$$ are at stake, so any advice from you experts would be real helpful. Thanks in advance!

I am getting into this discussion a little late but was excited that I actually have something to offer. I build houses and small appartment buildings and am often deciding what size service to go with.

The rule of thumb I use is that if it is possible that I might need 400 amps then go with 400 amps. It sounds simplistic but the cost of upgrading a service for 200 to 400 is a few hundred dollars. Wire from the pole, meter, and panel. The cost of doing it twice because the 200 amps is not enough is, of course, much higher.

In my area of the country 200 amp is standard for a 2000 sqft house with gas heat. If you have EBB then the service goes up.

Basically comes down to a preference. You can definately get by with 200 amp. If you run into problems you can turn off the stove, some of the baseboards, A/C, ect. But if you can't do that because thoses things are being used by a tenent (or something like that) then get the 400 amp.

Just my two cents/Doug

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I'm going to build a pretty big workshop on my lot (about 45' x 85') including a living space inside and plan on having a decent array of welders and machine tools along with normal things associated with a home - i.e. HVAC and possibly electric heat for the living area (about 1500 sqft), washer/dryer (all electric), general lighting, and maybe a Jacuzzi in the future. The large shop space will be heated with wood and or oil (no AC), so that shouldn't be factored.

Any ideas what level of service I should get (amperage wise)? They offer 200-350 amp service at a standard rate. Anything over 400 amps requires a load letter and a riser diagram (whatever those are) from an electrician. But apparently if I have the letter and diagram I can get 400 amps and over for no extra charge...if I properly understood the field rep yesterday anyway.

I need to decide here real soon, and as always big $$$ are at stake, so any advice from you experts would be real helpful. Thanks in advance!

MY SHOP IS 100X80 I HAVE A 300 AMP POWER BOX AND THAT JUST GETS ME BY, I DONT HAVE ANY LIVING AREA BUT I ALLWAYS HAVE 5 OR 6 PROJECTS GOING AT THE SAME TIME I HOPE THIS HELPS I WOULD PROBELBY BE FINE BUT I ALWAYS HAVE FREINDS AND FAMILY OVER TRYING TO HELP AND GETTING ME INVOLD WITH THEIR PROJECTS

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We have 150 amps running to the shop IT WAS NOT ENOUGH. Fortunaly we have all the power we could need at the pole, we have a crop dryer set up and have some thing like 800 amps at our finger tips. so adding another 200 was not a problem. What I am trying to say is plan on running several machines at once that way if your neighbor stops by to help you out you can wield while he runs the saw and the drill press and moniter the mill while your brother decides to run the 9'' grinder with all of the lights on and the heat going and the air compressed kicks in you do not find your self in the dark. OVER BUILD wih in reason and you will not regret it. IF you have 3 phase near by GET IT, 3 phase is cheaper and as some one said you can buy cheap toys that are cool. :D:D

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That's great to know about the sub panel meter. I hope I don't ever have a need for it though.

IF I REMEMBER RIGHT IT CLAMPS OVER THE WIRES GOING TO THE SUB PANEL. A MINI STORAGE COMPANY,&OTHER THINGS,USES THEM IF RENTER NEEDS EXTRA POWER FOR TOOLS,ETC. TO BAD THEY ARE 60 MILES FROM WHERE I AM LIVING AS THEY HAVE 12'X25' UNITS, HIGH CEILINGS,&YOU CAN BUILD LOFTS IN THEM.ALSO HAVE SOME WITH SIDE AND/OR END WALLS REMOVED.AND THEY LET YOU WORK IN THEM!ONE GUY RESTORES CARS(HIS OWN) RENTS 7 LAST I KNEW A 3 UNIT AND COUPLE 2 UNITS.ALSO USED TO HAVE A WAITING LIST

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Thanks to everyone for the very enlightening input. Especially thanks to Teddybear for the lengthy, detailed and informative post, I really appreciate the time and effort!

I'm still struggling with the electric company, I've been through the wringer with them so far. The lady who came out to my lot said she couldn't install the electric on a temporary pole, only run it to a building. Since I have no building yet, this wasn't going to fly. Plus she told me the electric coop is going to raise the install fee from $875 to what would equate to over $9000 for my long (800') driveway!! I about passed out when I heard that one. The electric company is trying to slide this new policy in under the wire, they gave virtually no notice to anyone. The only notice is on their monthly website newsletter, which says new rates will likely be implemented on the 1st of January. And of course how much work can really be done during December in the construction biz? It's cold, frozen, muddy, people are taking off for the holidays. They deadlined it on purpose in the dead of winter during a holiday season and only gave a month's notice so people (like me) couldn't react and get our electric in beforehand.

But, hopefully things are working out. I finally got the electric co to agree to install to a "permanent" pole at the end of my long driveway instead of a temporary pole. The electrician installed it yesterday, and although I'm not out of the woods yet, the nice electric co lady said I should be charged the old rate even if they don't end up connecting to the pole until after Jan 1.

And as far as amperage is concerned, I went with 350A. The pole only has a 150A box, but a 350A meter is on it. When I'm ready to wire into the house, the heavier gage wire is already wired to the pole, which is positioned right next to where the end of the building will be (i.e. the side I want the meter on). The electrician guy told me he's been working exclusively on these large custom homes, which usually run from 4000-6000 sq/ft in size. Usually with only a few people living in them! And he says all of them run 350A or even higher. Big heat pumps with electric backup heat, hot tubs, lots of lighting...it all adds up, requiring some big amps. I don't know what's been happening in Canada or elsewhere in the world, but home sizes have absolutely ballooned here in the US to absurbly huge "supersized" proportions. Anyway, it's interesting to hear that many get by fine with 150A-200A, even with sizeable shops. But these huge "McMansions" everyone's buying need 350A+!

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GLAD IT HELPED! THE CODE BOOK IS NOT EASY TO FIGURE OUT(THE ONE I HAVE-FROM DAD-IS A 1999)SO I TALKED TO DAD INSTEAD.THEN WITH EVERYTHING GOING ON HERE I FORGOT TO LOOK IN CODE BOOK FOR MORE INFORMATION.

TAKE CARE AND HAVE A MERRY CHRISTMAS!

PAUL

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There is a free software program that you can down load off the net, it is called calc wizz & it does loadings with demand caculations for domestic or commercial applications, just go to google & put in a search for electrical caculations, cable sizes

Reg

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