The phase angle determines what you get.
Anyway - most 3-phase apartment house services are in fact 180 split windings. e.g. delta with centers of the delta sides are grounded. You don't get multiple phases for normal home use.
Mart> Or 120 degrees out of phase if fed off a network three phase system. Ths can
That would depend where your located. This 120 degree system is quite common in some areas.
The voltages aimed at are 125 / 216 vac so that the 120v loads get a little high voltage and the 240 loads get a slightly low voltage, all within legal acceptable standards.
The energy metering takes a full two element Whr meter instead of a 1.5 element meter used for regular 120/240 vac. Costs a bit more so it it typically only used in high rises and other large residential blocks.
In apartment or condo blocks, usually each floor will be fed off two out of three phases, in the construction I have been involved with. One neutral conductor and three phase conductors can feed the whole building up the electrical service shaft. This can save some copper and use one big 3ph 4W transformer for the building. 6 phase star can be used in a similar method but power theft is easier to accomplish by customers and it takes more copper.
With a delta configuration only **one** centre tapped phase can be grounded. This was called 3 ph 4 wire delta and the metering was too complicated for many EE people and abandoned. This was common with a 120/240 vac residential service where the customer wanted to run a small 3 phase meat slicer or saw. A second transformer could be added at 60 degrees for open delta, quite economically and get three phase and single phase.
Anyway - most 3-phase apartment house services are in fact 180 split windings. e.g. delta with centers of the delta sides are grounded. You don't get multiple phases for normal home use.
Mart> Or 120 degrees out of phase if fed off a network three phase system. Ths > can
--------------------------------- HUH?
Residential construction in the USA is provided with the following:
Either 120/240, 3 wire Edison from a single phase utility x'fmr
or
240V, 3 phase, 3 wire with one leg center tapped and grounded.This is known as "Wild leg delta".
If you grab the wrong leg, you get 167V (Remember vector addition?) to ground.
Heard more than a few "war" stories about wild leg delta.
At one time was used by the small RECs as a means of reducing the amount of equipment req'd, but fortunately is being replaced, but you still might find some in the boonies.
The 3rd configuration found in light commercial such as shopping centers and some apartment complexes is 208Y/120/3PH/4Wire.
You get 208V leg to leg, 120V any leg to ground.
Utility x'fmr is 3 PH.
You need to be careful to select equipment rated for 208V, not 240V, or you will need a buck-boost x'fmr.
Lew
Dedicated 240VAC Circuits using 10GA is what I would suggest.
Not at all sure why you would run 120VAC outlets near the floor in a shop unless you have a specific tool in mind.
Someone suggested a ceiling outlet. I have one every four feet or so running two independantly switched circuits - one for my fans and the other (using three and four-way switches) for the shop lighting. One oulet on the lights circuit could be extended to the location of your table or shelving where your battery charger (tv or radio) will sit. This allows you to connect the chargers (drill, wireless phone, etc) and shut them down when you leave the shop. The compressor might also be on a switched circuit to prevent it from leaking down and recharging at three AM.
If you have a bench up against a wall (I saw none in your pdf), the idea of running outlets along the front edge is one I fully support and have implemented using power strips run under the table and up into the wall outlets.
120VAC outlets every 4 feet along the walls and six or eight inches above the highest work surface makes lots of sense and, again, I have implemented the approach in every shop I've built. For a little more cash, you can gang two duplex outlets at each location "just in case."I ran 8GA to the shop breaker box and breakers for each circuit.
GFCI can be done at the breaker box, but is not needed in dry location and can be a pain if the GFCI pops at one end of the shop when you are using something at the other. If you do get one, look for those with an Indicator LED. You only want one for a circuit, the other outlets "hang" off it.
There is also the unwritten rule of putting outlets at about 50" above the floor, so sheet goods will not block access to them.
--------------------------------------- #10AWG /W/ 2P-30A c'bkr will provide the lowest cost of ownership over the life of the system for 240VAC circuits.
Same can be said for #12AWG /W/ 1P-20A c'bkr for 120VAC circuits.
Lew
Also, in case you want to put your workbench in front of them.
There is also the unwritten rule of putting outlets at about 50" above the floor, so sheet goods will not block access to them.
You can run 10ga if you want, but regular romex works just as well. The up side is that you do not have to buy any special wire. The white and black are both hot and the bare wire is your neutral. I have my tablesaw, lathe and welder wired that way and have had for quite some time.
Deb
Hoosierp> Dedicated 240VAC Circuits using 10GA is what I would suggest.
OMG! Don't do that one! The bare wire should never be a current carrying (neutral) wire.
What did you use for equipment case ground?
Deb
No inspections in your pat of town obviously, that is dangerous.
Oh?
Please explain, in detail, exactly what you imagine is dangerous.
FrozenNorth wrote in news:i0u6ve$9u8$1 @news.eternal-september.org:
It's not a rule, but it's definitely written. It's one of my favorite "DOs" when someone asks about outlet placement and the like. (I suggest
54" to be sure the whole box clears if the installer measured from the top.)Puckdropper
Bare neutral instead of ground. No mention of proper tagging of the white as a hot.
For a pure 220V circuit it may be safe, but the bare is a ground, and wrap red tape on the ends of the white so it is *really* obvious if someone else ever opens that box.
HoosierPopi, I think I went with many of the suggestions you and other provided me with a few months ago. The electrical boxes are in and I spent about $400 on wire, circuit breakers, and accessories today!
Hoosierp> Dedicated 240VAC Circuits using 10GA is what I would suggest.
That's was I did. 3 on the bottom of the wall on the right.
See:
I put one near the back door, and a light switch where one would expect to find it.
See pdf above. I spent the cash! : )
I'm going to use 6-3 NM-B and a used a 60 amp breaker
I'm doing it at the breaker box.
Best, Bill
He's talking about a 240V circuit -- there is no neutral. He incorrectly referred to ground as neutral, but it's still a ground, and it's perfectly OK for it to be bare.
Technically, that's a Code violation, but it hardly qualifies as dangerous IMHO.
No. *Is* safe.
True.
Troll bait.
For a pure 220V circuit it may be safe, but the bare is a ground, and wrap red tape on the ends of the white so it is *really* obvious if someone else ever opens that box.
How is a 240V circuit supposed to be run? Do they make red/black/bare
12/2? I've always used a sharpie to paint the white, red.Use the black and white for the two hot legs. The bare is not to be used for a current carrying conductor...against the code(s) and DANGEROUS. In addition to many other dnagers of this you would not have a case ground for your electrical boxes and frames of equipment. Not a good idea and an inspector would make you take it all out and kick your ass hard!
I would run a 12/3 or 10/3 cable to have a neutral in case I wanted to install a device needing a neutral in a mind or usage change, later on. Then you would have red and black for hots and white for neutral, bare for ground.
12/2? I've always used a sharpie to paint the white, red.
Not that I've ever seen.
Same here. Red or black.
Oh, I musta misunderstood you incorrectly above, when you said that "tagging of the white as hot" was a code violation. I considered painting the insulation as "tagging".
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