Electrical types.. I need some help

[Char-Gar]

After thirty five years of living in houses not my own, I now own my own retirment home. I will at long last have my own shop space. I am in the process of doing the design work and need some help in deciding how to wire it.. don't worry I will use a professional, but I want to be able to tell him what I want.

Here are the specs.

The shop is 19' X 19'

I will have 6 to 8 double grounded 110/115 single phase plugs installed 42 inches above the floor. I want them above bench top height.

Here is what stuff that runs on electricty in the shop.

There will be six overhead light fixtures, three on each side and an switch for each side.

There will be an overhead fan with some lights in it as well. It will have a seperate switch.

A computor, printer, scanner etc. set up

A Radio

A 5" vent fan over the casting table

Lyman 20 lbs melting furnace

Floor model drill press (3/4 hp motor)

8" bench grinder (1 hp motor)

Logan 9 X18 lathe ( I forget what motor is on it, but it is not bigger than 1hp and is 115 volt)

If I can find the money I will get a Square D or Burr King belt grinder

A window air conditioning unit. I don't know whether to get a 115 or 220 volt unit....suggestions appreciated.

Throw in the occasional dremel, hand drill etc, and you have it.

None of the big tools will run at the same time.

I of course want a seperate breaker box and my questions are..

1) How many breakers?
2) What size breakers?
3) Which of the above goes on each breaker?

Like I said, I will use a professional electrician, but I don't want to be at his mercy dumb as a rock on the issues.

Thanks for any suggestions and help...please don't use much electrical speak as I really don't understand many of the terms.

[1Shirt]

Only advise that I would give, is for you to over estimate niumber of plug ins needed. Better to have extra and not need them than to go the other way around. 1Shirt!

[Pilgrim]

Just buy a standard 200A panel with 20 or so breaker slots. You will use two slots for 220 V stuff, and one slot for 120 V stuff. Use box mounted GFCI's instead of panel mounted GFCI's. I did the latter and it was a mistake cost wise, although I have no complaints re: effectiveness. The reason for the 200A panel is two-fold. First, they are the most commonly used panels and thus less expensive, plus it will be big enough to service anything you might want to do, including a welder should you decide to add one in the future. Additionally, the panel will have enough breaker slots so you can add more circuits in the future if you want/need more. Brand doesn't really matter, Square D is a good one but just check your local "Building Mart" and buy whatever they have that is big enough (breaker slot wise) and is at the right price. Most of your circuit breakers will be 20A, single pole and those will handle anything you have listed. However, I would buy a wall mount air conditioner (roof mount would be better, but probably more expensive...check) rated for 220V. Check around and you might be able to get a used one in really good condition from a HVAC outfit.

Ask away as you get farther along...PM would be OK to keep it off of the board if you would prefer. I put in a 400A service to my house and have been adding to it ever since. A 400A service is merely two ea. 200A panels side by side. It has been nice to have more capacity than originally needed, as adding circuit breakers is relatively inexpensive vs. a whole new panel. I've even put a 60A service from my panel to provide a second breaker panel for my pole barn. Added a 220V circuit for a Spa, and I still have slots not yet used.

Enjoy...FWIW....Pilgrim

[shooter2]

You should be able to give a good electrician just what you wrote here and he will advise you. It sounds like 150 Amp service would be more than sufficient. The number of breakers the box will hold is determined by the service size (100A, 150A, etc.). Be sure to put in some 220V outlets. Have GFI's put in on all circuits.

[Char-Gar]

What does GFI or GFCI mean? I have no idea what that is.

[GSM]

How about an outlet for a refrigerator?

Also, if there is room, look at a mop sink and a small water heater.

[felix]

See, you are already adding stuff! Go with the cheapest boxes per Pilgrim. If you can get 3 150's cheaper than 2 200's, so be it, do it. It is not really the number of AMPS, it's the number of seperate circuits that is important. This makes it handy to put in bigger wire for areas that will use the bigger amps. I use 10AWG wire for air conditioners, or anything that will drive a compressor, like an icebox. If you have an option for a particular peripheral that is 120 or 220, pick the 220. Not cheaper to run, but easier on the wires. This will allow you to use 12AWG for the lighter duty machines. If you have the bucks, put in a slow-start for all motors that start and stop often, like air conditioners and exhaust fans. Not cheaper, but 10 times less maintenance. Trade-off. ... felix

[Bigscot]

GFI/GFCI- Ground Fault Interupt/ Ground Fault Circuit Interupt.

http://www.doityourself.com/stry/gfci

Bigscot

[1Shirt]

Charger, GFI=Ground Fault Interupter, GFCI = Ground Fault Circut Interupter
They are safety devices and all new electrical installations should include same. Might save a fire!
1Shirt!:coffee:

[grumpy one]

Our Australian supplies are different (240 volt for general purposes, 410 volt three phase for anything serious) but some of the lessons I have learned might still be relevant. First, a 19x19 room is big enough to be flexible as to future use, so it makes sense to allow for this in the first place - rewiring is only easy if you are staying within the original capacity intent. Second, all the things you have mentioned are very low load items, but the future might hold something quite different.

A couple of simple examples of what can go wrong. I started out with normal (for us) 10 amp (same power output as your 20 amp) 240 volt circuits all over the place, and two three phase outlets for lathe and the odd 3 phase item such as my filing machine. The three phase power shared main fuses with the 5 horsepower central air conditioning, so I could only use 15 amp 410 volt fuses or I'd compromise the protection of the air conditioner. This set-up didn't work: 10 amps at 240 volts (or 20 amps at 110 volts) won't run a decent arc welder. Even 15 amps at 410 volts won't run one of mine (because it uses series resistors in the transformer primary to adjust current, it is very inefficient). So, I had to add a specific 15 amp 240 volt circuit so I can run a proper 230 amp choke-type arc welder. I still can't run my 410 volt welder above 100 amps, or it blows the air conditioner fuse. The outcome is two arc welders to do the job of one - for sheet metal I use the 410 volt one, and for heavy stuff I use the 240 volt one. In the end I get the job done but I'm doing it the hard way.

The second problem was number of 410 volt three phase outlets. I only had two installed, but I finished up with way more three phase devices than that, so I have to keep switching plugs, which is a small irritation though nothing important. My lathe, mill, filing machine, disk sander, and one of my welders are 410 volt, because that was the best deal when I was buying them (private buyers detest 3 phase stuff here, because they don't have three phase wiring in their homes. Consequently I can buy that kind of machine second hand dirt cheap.)

If I were starting again I'd have a lot more 410 volt outlets, and they wouldn't share fuses with the air conditioner. I should have invested more in the wiring in the first place - which is the point I want to suggest here.

The other comment I'd make is that your exhaust fan plan sounds hopelessly inadequate to me. I use a 12 inch exhaust fan just to extract the smoke caused by heavy cutting on the lathe and mill - I'd want a bigger one if I used that room for smelting.

[PatMarlin]

Here's another consideration to the equation...

You need to know how long a run from the breaker to your amp draw on each machine etc, to size your wire gage and circuit accordingly.

Here's a cool calculator to tell you exactly what size to run:

http://www.powerstream.com/Wire_Size.htm

:drinks:

[schutzen]

1st Service sizing : Are you going to make this a separate electrical service with a separate meter or will this be a sub feed from your house? This will probably depend on the size of your house meter. 200 Amps on a small to moderate sized house, sub feed 60-70 amps to your shop. If your house is larger or if the electrical meter is less than 200 Amps, you will need a separate meter. The size you choose will depend on your electrical distributor's rules. In my area a 100 or a 200 Amp meter cost the same, but 10 miles down the road a 100 Amp meter is $10 per month less than a 200 Amp meter.

2nd Receptacles : All general use receptacles should be the 20 Amp duplex receptacles. I prefer to place them at 52" in a shop or a garage. A 4'X8' sheet will prop against the wall and leave the receptacle useable. I also like a receptacle every 36" along a bench.
Every other receptacle should be on a different circuit breaker. Example: receptacle 1 on circuit A, receptacle 2 on circuit B, receptacle 3 on circuit A, receptacle 4 on circuit B. This allows you to use several electrical tools on a bench without overloading a single circuit. Definitely place your casting bench on a separate circuit. A 20 LB pot draws 17-18 amps. I would also dedicate a circuit to each of your major power tools, i.e. the grinders, drill press, and lathe. Larger electrical motors tend to falsely activate GFIC's. (If the grinders and drill press a small bench models, this may not be necessary.)

3rd Lighting and Ventilation : All of your lighting and ventilation can run off a single 20 amp circuit.

4th Heating and Air Conditioning : Given your location as south Texas, this may be A/C only. Regardless, dedicate a 240 Volt 40 Amp circuit to this. That is 2 poles in any box.

5th Your Main Question : Ok what are we looking at? 5 dedicated single use receptacle circuits for specific tools. (These should not be GFIC protected and should be single, not duplex receptacles.) 4 general use receptacle circuits. 1 lighting circuit. 1 240 Volt heating and A/C circuit. 5+4+1+2 = 12 poles 40amps A/C + 20 amps dedicated tool + 20 amps general use receptacle + 20 amps lighting = maximum usage of 100 amps. My answer would be a 100 AMP 20 pole Distribution Panel. This could be either a sub feed from a larger panel if it has the capacity or a separate 100 Amp meter.

One other piece of advice, definitly hire a professional to wire this for you. In my area there are numerous "handymen" who wire house projects. Some of these guys are very good, but some create "death traps". Hire someone who has an "electrical installer’s license". These guys do not make the wages a "union electrician" makes, but they do have enough training to make a good installation.

Addendum to #5: I may have confused you. The 5 dedicated single use receptacle circuits are 1 single receptacle on a single 20 amp breaker for a single tool. i.e.: Lathe plugs in to a single receptacle on a single breaker. The general use receptacle circuits have multiple duplex outlets wired in series. The National Electrical Code requires all general use receptacles in a shop or a garage to be GFIC protected. The dedicated single use receptacles are exempt from this requirement.
Installing these in surface mounted conduit in a block building is much easier than installing the conduit in the wall as it is laid up.

[trk]

Let me toss out a few things:

The NFPA (National Fire Protection Association) publishes, among other things, the NEC (National Electric Code).

The NEC is a volume of RECOMENDATIONS that is usually adopted within a year of publication (every 3 years) by the state legislature.

In Virginia, may be different in your state, it is the BUILDING OFFICIAL that has the ultimate approving authority for the locality's building permit. Some, obviously are more strict than others. He is THE person to make happy.

Residential rules are different from commercial.

Some general rules of thumb:

Motors: allow 5/4 the amperage (to account for starting current).

20 amp circuits: may have up to 12 outlets (might be a little light considering shop use, but then if it's a one-person shop maybe not).

30 amp - 10 ga wire
20 amp - 12 ga wire
15 amp - 14 ga wire
(Use heavier wire for longer runs.)

Figure 2 different circuits for lighting - just incase one goes down you're not in the dark.

ALL outlets should be GFCI (it's a shop).

Run separate (dedicated) circuits for larger or specific pieces of equipment.

Plan your equipment layout and design you electrical plan around it. The NEC manual has examples - you CAN do the calculations yourself.

You may have to submit the plan to get building permit approval.

[454PB]

I've been where you are, only I did the work myself. Here is a link to a post some time ago that may be helpful:


http://www.castboolits.gunloads.com/showthread.php?t=7078

[Dale53]

Chargar;
No one here has mentioned using computer gear in a smoky, dusty, atmosphere. I would strongly suggest that you contact a really knowlegeble computer technician and see what he recommends regarding putting computer equipment in that environment.

Understand, I don't know, myself, but dust and smoke is generally considered a BAD thing with computers.

Just a simple "heads up" to carefully check out (computer equipment is entirely too sensitive and expensive to put it at risk).

FWIW
Dale53

[Catshooter]

Trk has given you the most accurate advise, as far as electrically technically correct.

GFIs. The way they work is they measure the power going out and compare it to what comes back. If there is too much difference (in your case, about 5 thousanths of one amp) it kills the power. It is not there to stop a fire, it's there to protect you from the power that isn't coming back the way it should: it may get loose and try to go through you.

You can do GFIs two ways; with a breaker or with an outlet. The breakers will protect you no better than the outlet but cost about 4 times as much.

In no case inside your shop do you need to allow for distance. You don't need to go up a wire size, your shop is way too small for it to matter.

More outlets is much better than needing one more.

I run everything you list out of a small panel covered by a main 40 breaker. I also have a 5 horsepower air compressor (220 volt). But mine is a one man shop, so how much equipment can you use at once? Any automatically controlled load you should take into account, like your A/C because it can start while you are running something else.

I have been an electrician for more than 32 years. Hope all these posts help.


Cat

[Char-Gar]

Dale.. Thanks for the heads up.. I don't think it will be much of a problem. All of the power tools and casting bench will be on one side and the other side will be books, gun safe, storage and computor desk.

I am not going to be doing any welding or power sanding. The only smoke, might be a little off the flux in the casting furnace, but it will be under a hood with a good vent fan.

Guys.. Thanks for all of the great information.. I am very greatful.

[crazy mark]

20 amp circuit according to NEC has an allowable max draw of 16 AMPS. 80% of max ampacity. Lead pot should have a dedicated service.
15 amp circuit has a max allowable of 12 amps. These are for safety reasons. Most states won't let you have a 200 amp panel feed another 200 amp panel. There is the 12' rule however that lets you put another panel a max of 12' from your meter base but you would have to upgrade your meter baseand wiring to same and drill and tap for lugs to go to a 200 amp fused disconnect to feed your new panel. Best bet is add another service and pay the extra dollars.
Also check with your local building codes division as they can be more restrictive than the National code.

[Dale53]

when I had my utility barn built, I had two separate circuits run to my casting area. I wanted to be able to run two lead pots at once, if need be. The separate outlets are just 36" away. Both walls of my shop have outlets at six foot spacing.

If you use fluorescent lamps overhead, you will need "cold weather" lamps unless you have a constantly heated building. Standard lamps will not want to light in cold weather.

Good luck!
Dale53

[MtGun44]

GFI isn't intended to "prevent a fire". A fuse or breaker will prevent a fire
just fine. The point of a GFI is to sense a fault to ground in a VERY short
time and shut down the power, MUCH, MUCH faster than a breaker or
fuse. WHY?? To prevent you from being shocked or electrocuted if you
manage to get well grounded with a hot wire in contact. I haven't kept up
with code changes, but IMHO GFIs are only necessary (likely to provide
benefit for their significant cost) where you can get something electrical
into water. In the past (may change as the code folks seem to be primarily
interested in keeping the electrician and plumber's unions in a lot of work)
this was primarily in the kitchen and bathrooms (water to make a good
ground). Maybe today we aren't safe if they aren't on every circuit. BS
IMHO, but ultimately you'll probably have to meet code. I get a bit
cranky at codes because it seems like a never ending increase in cost
and complexity in the name of safety, and who can argue against safety?
Do we all need to wear crash helmets all the time 24/7? It would make
us safer . . . .

One recommendation. Put in an outlet every 4 feet on the wall. Outlets
are dirt cheap and I really am sick of extension cords and outlet multipliers,
etc. Just wire up a whole bunch of outlets, even double or triple outlets
where you may need more. Cheap as heck to do at installation, really.

Bill

[Lee]

Chargar; what they have all said so far. Unlike casting boolits[smilie=1: , everything these guys have told you is correct. Better safe than sorry. Now my advice is this; Get 3 estimates, and tell them that you are looking for an estimate(documented with what is going to be done) That will give you an idea of what it will cost, and might save you from getting screwed by a "handyman" or other scoundrel.......... Just like in medicine. If you don't like what the Doc tells you, get another opinion. When they all tell you the same thing, well then it's time to put your affairs in order!:(
Estimates, along with references and applicable "licensing" will allow you to make a confident pick of who will do your work............Lee:)

[spottedpony]

(Licenced master electrician here)
per NEC calculations minimum general purpose recepticles and lighting load calculates out to just under 10 amps (sq feet x 3va / 120 volts) so in theory 1 - 15 amp circuit is adaquate, HOWEVER there are additional factors to apply here.

what sort of lighting fixtures? flourescents, calculate @ .75 amps for 4 foot two tube fixtures, and 1.5 amps for 8 foot two tube fixtures, unless your going with HO (high output) those draw just over 2 amps per. with transformer type lighting to be calculated at 100%

What about heat? you mentioned no heat source, but again per NEC, when calculating service size the smaller of the two loads can be ignored, as a dissimilar load, NEC assumes heating and air conditioning will not be used at the same time. oh and go 240 volt on your AC, as it will be more energy effecient. half the amp draw as 120 volt, and amps are what you pay for when the bill comes.

My suggestion, and the way i'd do for myself would be to dedicate a circuit for your melting pot as it will see more continuous use then the following circuitry as a general guideline.
All general purpose outlets will be required to be gfi protected and i suggest using the gfi recepticle, not the gfi breaker, due to cost. protection effeciency of both types of device is the same.

depending on local code you may be able to share 2 motor loads per circuit, IF its not likely you will use 2 tools at the same time, though code may require a seperate circuit for each one.
the 3/4 hp motors will pull a nominal 14 amps per motor and the 1 hp @ 16 amps per. if the one hp motor ratings are higher (and this depends on motor type) you may have to go to a 30 amp circuit again with the possibility of sharing as long as 2 tools will not run at the same time.

one thing to check, if your tool motors are split phase, that is can be wired to run on 240 volts instead of 120 volts, then at 240 voltage, your amp draw will be half of the amp draw of the same motor at 120 volts.

calculated load for your building size, with the load you have mentioned, is 75.75 amps EXCLUDING allowances for electric heat and with additional electric heat load right at 80 amps, (because of dissimilar loads AC which would be the smaller load can be ignored)

In any event a 100 amp panel would be adiquate, though i would install a 125 amp to allow for additional load in the future.
I saw in a previous post, a 200A service suggested, but imho that is greatly overkill and you'd be spending needless dollars.

To give you an idea, my shop is 24 x 32, 6-eight foot flourescent lights, garage door opener, 2 welders, bench grinder, drill press, wood lathe, radial arm and table saw, band saw, 2 disk/belt sanders, 60 gallon air compressor, electric heat/ac plus a multitude of various hand power tools, And hot tub load is also on the shop panel. all this is connected to a 100 amp panel and no problems what so ever in 10+ years.


100 or 125 amp 16 or 20 circuit panel would be sufficient.

note that the circuits listed below are breaker size NOT actual amp draw of the load mentioned. & may vary with local code requirements.

lighting one circuit @ 20 amps
AC (240 v) two circuits @ 20 amps
Lead pot one circuit @ 20 amps
dedicated tools 4 ckts @ 20 amps with the possibility the 1 hp motors may require a 30 amp circuit each.
general purpose circuits 3 ckts 20 amp

breaker capacities:
# 14 wire = 15 amps
# 12 wire = 20 amps
# 10 wire = 30 amps

A suggestion too, while it may cost a bit more initially, i would run all circuitry in conduit in the walls, as opposed to romex, particularly if you plan on insulating and finishing the walls. This would make it much easier for future maintence and additions. at the very least, have your electrician run 2 or 3 spare 3/4 inch conduits into the ceiling space for future use.

You will find its more dollar effecient to have a seperate service installed, rather than upgrading an existing house service if necessary to meet the additional load requirements.

[Char-Gar]

The house and garage, which will be the shop, is built from cinder tile block. Ergo, the shop walls are solid masonry and I don't intend to chip into them to recess the wiring. All wires will be in conduit attatched to the inside wall.

[hpdrifter]

that makes it real easy. listen to spottedpony, catshooter, and trk and run all circuits in conduit; emt. Addding later will be easier also because it's all "exposed". can't really see why you'd need over a 100 amp capacity, but like some have said, if you live in a city where you need a "permit", the inspector is the final hurdle.

[drinks]

Texas has been licensing electricians for the last 4 years, does not mean much as the law had a grandfather clause that let any jakeleg who could get some shop to sign a paper that the person had been twisting wire at least 4 years to get a license without taking a test.
Put plenty of receptacles, every 4 feet sounds good, the 42" high is great, GFCI protection is required within 6 feet of a sink, or similar. 2, 240v receptacles on each wall would be nice, the tools you describe would be happy with 20 amp circuits.
You do not have to worry about a GFI, they are used on switch gear of 1200amps and larger and trip at 200-300 amp. For an insulated building of 361 sq.', 10-12,000 btu would be plenty and would draw about 8 amps on 120v,with a eer of 10 or better, I cool 196 sq. ' with a 5500btu window unit, in Texas.
A 100 amp panel with a 12/24 space rating in GE or similar would be plenty, breakers are cheap and can be found in most any supply or hardware store .
Spotted pony;
You seem to have amps and watts confused, the wattage is what the power company bills you for and 10 amps at 120 v or 5 amps at 240v are both 1200 watts.
The only possible savings with 240v over 120v is in the slightly smaller I2R losses in the wiring due to the resistance of the wire.

[felix]

Air conditioning is somewhat tricky in that it is difficult to truly estimate the amount of cooling required. This is because of the humidity/heat built up in the building walls and its retention capabilities (when conditions immediately change inside), and mostly particularly based upon your temperament as you enter after mowing the lawn, for example. Typically, a workshop is kept entirely ambient during the time you are not present, allowing the building to join up with the average ambient weather conditions outside. Therefore, your best AC system, heat included, should be at least double the capacity as would be required during full time operation. When specing a system out, I like to have a unit that has a variable speed fan control to slow the fan when the humidity is too high, and then raise it above average when the humitidy becomes too low, especially during the winter when I want heat distribution as fast as possible and retain as much ambient moisture as possible. Something to consider as I have personally done. For example, I designed and installed an air augmentation system for my house that kept a 3200 sqft house at 25 percent humidity at 72 degrees during a July family reunion with the doors of the house constantly being opened and closed over a 8-10 hour period for 3 days. The party had no less than 60 folks continuously (it seemed). ... felix

[Nueces]

This is not a thread hijack, only a short, scenic side tour that I hope all will enjoy. :-D

felix, if you would, please elaborate on your air aug system. PM invited if you think it'll be too long for here.

Thanks, Mark

[slughammer]

...In any event a 100 amp panel would be adiquate, though i would install a 125 amp to allow for additional load in the future.


Great post, all of it. But that part about buying the amps? I buy kW. P=IE.

I like your ideas of sizing and running wire in conduit. I need to wire my 14 x 28 shop. I'm thinking about insulation and sheeting first, then using conduit on top of the sheeting. Any thoughts about using a running board and then dropping down conduit to receptacles? Makes the whole system easily adaptable for new equipment and changing floor plans over the years.

[felix]

Ask me some questions, Mark. That would be the best way to explain. I need a place to start, in other words. ... felix

[felix]

Yeah, Slugs, you are buying AMPS over time, where both vary considerably. They supply the voltage, which hopefully does not change. In reality it does, and you can really raise hell with the power folks if you want to. It is difficult for them to change the actual voltage from what you have, but you can optimize the voltage they deliver at your house by having them install capacitor(s) on your light pole, The objective would be to assure a constant phase angle between the voltage and current when you turn all the motors on in the house at once, and let them run hot, or as hot they will ever get. That would be the worst case. The best case would be when running the house/barn in the most usual fashion, like having the air conditioners running, stove, icebox running, washer and dryer, dishwasher, etc. during the day normally and have them trace the relationship between the voltage and current. I would have them see what the normal peak was, calculate the RMS values, and then place the proper sized average capacitor on your pole to make the best compromise. ... felix

[Nueces]

Ok, felix -

Since you mentioned humidity control and constant inside/outside air exchange, I figure you put in some combination of increased household air mixing, dehumidifiers and/or temporary additional A/C capacity. Sorry if the HVAC terminology is *****ed (I'm a physicist). I know that a major part of one's A/C energy use is air drying. So, I suppose one could use one of those mold remediation type air dryers to take the load off of the house A/C system, thus increasing it's cooling efficiency. Does this get you started? :)

Mark

[felix]

Yes, Mark, you are correct. Drying the air is a major consideration in making one feel it is actually colder than it is. It takes 7 degrees off of the body to evaporate sweat, making the room actually 7 degrees colder than it is. Of course, you know that. But how dry does dry have to be to make that happen? That is the 64 dollar question at any one moment in the house. Yes, a dehumidifier will work good. But.....using the typical dehumidifier won't work cost wise because you are using a compressor to press the water out of the air, without any additional cooling support from an artificial "coolant". If you are running a compressor, you might as well get all of the support you can. Using a 30 degree coolant (freon 12) you can subtract up to 30 degrees off of that air. Using a 20 degree coolant (freon 22) you can subtract up to 20 degrees off that air that actually TOUCHES the coils. You have to circulate that air over and over to get all the air in the room. A typical "under the curve" problem, if you will. Next question. ... felix

[Nueces]

Thanks, felix

What were the equipment components you used?

Mark

[felix]

Custom made here in AR, by Hydro-Temp. They have all kinds of stuff to do just about anything. You have to talk to them in detail about what you want, versus what they have in immediate stock. Their engineering is quite good when left up to them, after they know in detail of what you want. If you decide what you really want to do, I will help you talk with them. They know me quite well.

http://www.hydro-temp.com/

felix

[spottedpony]

Great post, all of it. But that part about buying the amps? I buy kW. P=IE.

exactly right
KW = kilowatts or 1000 watts = 1 KW
1KW/240 volts = 4.16 amps and at 120 volts would be 8.32 amps.


watts converts to amps, (watts/volts = amps) which is the more common term used, so in essence even though your billing comes as KW used, its all one in the same.

You do not have to worry about a GFI,
Not necessarily true, NEC requires gfi (or gfci, both terms are commonly used and are the same for all practical purposes) protection in certain cases, among others, shops/garages, whether finished or unfinished, though local codes are the final juristicting authority.



Spotted pony;
You seem to have amps and watts confused, the wattage is what the power company bills you for and 10 amps at 120 v or 5 amps at 240v are both 1200 watts.
The only possible savings with 240v over 120v is in the slightly smaller I2R losses in the wiring due to the resistance of the wire.

drinks,
contrary to what you have posted, watts (or kilowatts) and amps are exactly the same thing, just different units of measurement, as you stated, 10 amps at 120 v or 5 amps at 240v are both 1200 watts. However,while the following is only true in a scenerio we see in countries where 240 volt appliances are supplied by multiple conductors, if you research the difference in running a multi voltage compatable appliance, motor in this case, you will find that instead of supplying the entire motor load on one power conductor, the load is (more or less) equally divided between 2 power conductors. (look at a multi voltage motor sometime, and compare listed voltage/amp requirements at the different voltages) Thus if you have a 1600 watt draw at 120V, on one conductor, then at 240V, where the power supplied is carried by two conductors, the wattage draw per conductor is half, so you have (nominal) 800 watts on phase A, and 800 watts on phase B for a total combined wattage of 1600 watts. among other benefits the advantage of lower amp draws Per Phase, of higher (than 120 volt) usage are material costs, smaller conductors, smaller amp rated breakers, and the list can go on endlessly.
As far as not realizing any savings running 240V vs 120 V, when possible, try hooking a known load at both voltages up to a check meter sometime, you'll find that at 240, the amp (or watt, or kw) draw is half of the same load at 120.

[No_1]

Charger,
I am not an electrician. I am a person much like you. When I want to do or get something done, I research to get some knowledge then consult local professionals for their professional advice. (This is not a slam on anyone who has posted here but as everyone knows, each and every area has it's own particular rules and regulations.) Those locals will have intimate knowledge of the issues you will face when dealing with the local code inspector.

Where I live, a person can have the basic shop built (finished outside but bare inside), have it inspected, have a licensed electrician install the fuse panel (whatever amps) hooking up 1 light and 1 outlet, have the licensed plumber install the first water pipe, call the inspectors and get a clean bill of health. Then that person can work on his own to add whatever he wants without the hassle of the inspectors. This is the cheap way out HOWEVER, in case of catastrophe which involves work done by the owner there maybe issues with your insurance provider.

I am sure you have dreamed of the perfect shop for many years just as I have. I work out of a 2 car garage since my deed restrictions on the present house do not allow out-buildings. In my garage I have 2 drill presses (220 and 120 volts), a small lathe (120 volts), a 60 gal air compressor (220 volt), a medium size mill (220 volt), a grit blast cabinet, a pedestal grinder (120 volts), fridge, microwave, computer, TV, radio and so on. My breaker panel is in the garage and is 200 amps. It has 10/220 volt breakers and 14/120 volt breakers. There are still 6 slot left. Keep in mind I have 2 central a/c's on the house, a pool, double ovens and a huge spa tub. Anyway, for my shop additions all work was done by a licenced electrician and he said I am at the limit for my existing setup.

With your design which is simular to what I would like to have at the next house (and I have consulted a license electrician for the following info) I would use the metal conduit running at ceiling level that drops down to the outlets that are needed. You should be able to make 1 large run that circles the shop. Connection boxes would be equally spaced along that run and you could drop down from those for your outlets. For the time being you drop down where you need and the extra connection boxes are for future use if you need them and easily wired since you can use a fish tape to pull addition wires. My area allows (when using ridgid conduit) the use of single wires (not romex) to be used. He also recommeded that the shop has it's own meter.

He indicates that even though most houses have decent breaker panels, they are pretty much set up for the stuff that is in the house. The home builders do not try to "forecast" the needs of the future occupants, they only see present needs and the least amount of $ spent to meet those needs. Since a majority of the owners are not fiddlers like us the existing (house only) power needs are met but when you start adding stuff like we have, the power needs increase dramaticaly.

What I have written is just info I gathered through my research. Use what is useful and discard the rest.

Good luck and post pics when done!

Robert

[slughammer]

As far as not realizing any savings running 240V vs 120 V, when possible, try hooking a known load at both voltages up to a check meter sometime, you'll find that at 240, the amp (or watt, or kw) draw is half of the same load at 120.


Just the Amp draw is half, but then voltage is 2X, and therefore the power purchased and the electric bill is the same (ignoring a very slight benefit in efficiency).

Watts are power, a measure of work, same as HP, just different units.
Amps are a measure of current, or flow.

http://www.sengpielaudio.com/calculator-ohm.htm

[felix]

The only real savings you are going to get is getting the power factor corrected by the utility company for a normally working day. If you cut the voltage down by not having the power factor corrected, the amperage will go up to compensate to make power requirements that are demanded by the equipment being powered. The power station still sees the voltage as delivered to the light pole, and not the voltage as delivered at any one moment within the house. After the entire remodel job is finished, and stabilized for a few months, perferably a year, then call the power company for a power factor checkout. It might save you 100 bucks over year of billing, but more importantly, it will save your motors wear and tear that are everywhere throughout the house/barn, not to mention your electronics (power supplies, more specifically). .... felix

[Nueces]

Thanks, felix - I did a quick walk-through of their website and will keep them (and you) in mind, since we will likely move soon and I may be able to spec a shop. I confess I had thought of your 'fix' as being temporary, to deal with a one-time load of people. It now appears that you had much more in mind. Thanks much for the link and the offer of help - very nice of you.

Mark


Custom made here in AR, by Hydro-Temp. They have all kinds of stuff to do just about anything. You have to talk to them in detail about what you want, versus what they have in immediate stock. Their engineering is quite good when left up to them, after they know in detail of what you want. If you decide what you really want to do, I will help you talk with them. They know me quite well.

http://www.hydro-temp.com/

felix

[felix]

Mark, their website stinks! Obviously, they put their time into the operation where it really counts. Their marketing is done only by one person, who caters to commercial installations only. I by pass him everytime I need to talk to someone. ... felix

[Nueces]

felix - Ok, then (back from getting daughter from movie theater). I'll feel free to pester you directly, when the time comes. :-D Thanks again for offering your expertise.

Mark