How do I wire up a 480v Single Phase circuit? I'm familiar with 480V
3P but not single. The machine has a preinstalled 3-wire cord, one of which is a ground so I'd only be using twom wires.Also what exactly does poles mean? Like a circuit breaker is either
1-2-3 poles, is that the same as phase? Thanks.
"Single phase" 480 is just like single phase 240 residential service, only at a higher voltage. It's called single phase because the voltage is derived from a center tapped transformer fed from one single primary.
I've never seen a single phase 480v service. 480 is commercial/industrial in nature and it's generally supplied as 3 phases.
This is Turtle.
480 volt single phase motors / equipment is very rare to say the least. There is only one i know of and it is the 480 volt HVAC rooftop systems which have 480 volt condenser fan motors on them. First you have to get 480 volt service to the building which only comes in 3 phase service and just use two of the hots of the 3 hots for power. If your thinking of running this at your house. the cost is going to be high to get 480 volt service to your house. The electric company will supply you with 480 volt service for about $4K atleast and then you have to be set up to have the switch box for the 480 volt serice.Now you can look into getting a buck and boost transformer and get 480 volt service out of your home 220 volt service. That will run you about $2K atleast.
You got me here with what you would have that runs on single phase 480 volt that could be useful to you. It would be nice to know what it is.
TURTLE
According to HA HA Budys Here :
I think "poles" means "hots" in this context. You have two.
I think he's just pulling two hots (out of three) from a 480V three phase feed.
At that voltage, I'd normally hire an electrician just to be _damn_ sure I don't do something dumb.
Most 120V stupidities are survivable. I consider 480V instant death.
[During the ice storm we wired a 600V three phase 200Kw generator. In an emergency, you gotta do what you gotta do. But you can damn betcha we were careful, and warned everyone that sticking one's hand into the step-down transformer was not just dangerous but instant death. They paid attention.]480 volt single phase is any two phases line-to-line of a 3 phase 480 volt system. If you had to ask a simple question like that, it would be in your best interests (and possibly others) NOT to be messing with it. Call a qualified Commercial/Industrial electrician.
Poor description--two phases ???
According to PrecisionMachinisT :
Not really. "Two phases from a 3 phase circuit" is a perfectly reasonable way of saying it. Doesn't make the resulting circuit two phase tho. It's single phase. Hint: if you were to scope one hot relative to the other, it's still a simple sine wave.
Yes, really....
"Two phases from a three phase circuit" would better describe a circuit connected to a three phase supply through three wires but having no load across one of the phases.
Hint: our shop has a single phase service at 400 amps, we buss 170 amps of this to generate our own three phase power via rotary transformer in order to supply the machinery.
At any rate, a better description IMO would have been something like " a two wire service, usually one phase of a three phase supply"
Hello, Turtle.
You gots me there too--mebbe he found some lights for cheap and is gonna grow dope or something.....
Now for a small load, a transformer for 220/440 shouldnt be too expensive on the surplus market though--Ebay, perhaps.....
This is Turtle.
I have very seldom that a small load on something that uses 480 volts to pull it. You use 480 volt service to get it on for power of anything using it. other than that 220 volt service will run a great deal and easler to find power for it.
Awwwwww E-bay for quality stuff. Not Me.
TURTLE
Okay--agreed......
Still he leaves me to wondering what exactly is it he is trying to fire up here ???
I have transformers do this 220/440 and vice versa but alway for 3 phase stuff.
One phase to neutral of a 480 volt 3 phase supply is single-phase but the voltage is only 277 volt. The OP wanted to know what single-phase 480 volt was. Chris was absolutely right, whenever 2 phases of a 3 phase system are combined, the resultant sine-wave is single-phase. (It's called single-phase because _that's_ what it is.)
On a 277/480 volt 3 phase Wye connected system (which is VERY common and most likely what the OP has): Single-phase 277 volt is one phase to neutral. Single-phase 480 volt is any two phases, line-to-line.
The same is true for the also so very common 120/208 volt 3 phase Wye connected system: Single-phase 120 volt is one phase to neutral. Single-phase 208 volt is any two phases, line-to-line.
Like Turtle said, a single-phase 480 volt load is very uncommon. Usually you'll see single-phase 277 volt loads (one phase to neutral, very common for Commercial lighting) sharing the neutral on 3 phase branch-circuits, or
3 phase 480 volt (with no neutral) for motor loads.One example of a single-phase 480 volt load, though, is Commercial parking lot lighting. While 277 volt for parking lot lighting is more common, in somes cases the light ballasts are sometimes connected single-phase 480 volt (any two phases line-to-line), when the runs are very long. A 3 phase 480 volt feeder is provided and the load is balanced accordingly. That is, the first light pole is connected phase A to phase B. The second light pole is connected phase A to phase C, the third light pole is connected phase B to phase C, then repeat for each additional light pole.
Another example of a 480 volt single-phase load is a control transformer for a motor controller. Usually the motor circuit is 3 phase 480 volts, but the desired control voltage is 120 volts. In that case, a single-phase 480 volt (line-to-line) control transformer is connected across any two phases of the feeder (properly fused, etc) and steps it down to the 120 volts.
Like others have stated, I'd like to know what the 480 volt single-phase load is that the OP is talking about. If I were to guess, I'd say something with a heating element. That's why I told the OP to call a qualified COMMERCIAL or industrial electrician, because if the load is really single-phase 277 and he slaps 480 single-phase on it, it's toast. Plus there are other, mostly safety issues, that he probably isn't aware of.
I originally thought it might be a heater too, as I've seen very few single-phase 480 motors. Many of the mid-sized infrareds I've seen are 480 single phase... the bigger ones above 7 kW or so are three phase but can be wired single if you've got the amps.
Dope growing is something I've heard these things are used for.... my brother's a police officer and has told me some of the stories on these nutty hookups. I'm also told that in some areas they ask the power company to report 'unusual' high residential loads to the cops for further investigation. They even have heat-sensitive cameras so they can sit outside your house and look for warmer rooms.
It would be interesting to see what the OP has here, and what he wants to do with it.
Jake
Jake wrote: ...
Ah, the 4th amendment. How I miss it.
I wonder if he (the OP) really wants "single phase" or is misunderstanding his own needs.
Horse shit.
Makes absolutely no differance how it is derived--could be from a single phase generator, or battery backup with an inverter and still be single phase.
You need to toss the three phase reference out the door because it is of absolutely no value in defining single phase power.....
You have the cart in front of the horse--three phase being three single phase circuits that are 120 degrees out of phase from each other, connected together in a star or a triangle configuration.
And by the way, anyone who knows diddly squat about power distribution is likely not very impressed at your obvious attempts at further clouding the issue by your rattling off various types of three phase service, bringing in line to line and center tap voltages, control transformers, streetlight wiring and all the rest of the irrevelant crap.
Have a nice day.
As you know from your experience with 3-phase power, the voltage between any two of the hots is full voltage while the voltage from one hot to neutral is related by square root of three. Thus 480/277 volt systems that are common in commercial industrial buildings where the lights use 277 and the motors use 480. To get 480 single phase you can use any two of the hots and wire them to the two wires that are not your ground. If you have more than one of these items to hook up, do what you can to balance the load by not hooking all of them across the same two hots (say phase A and phase B). Be sure to use boxes and switches rated for 600 volts not the usual sort rated for 240 or as they say you'll be sorry.... If you have any doubts, hire a qualified electrician.
Get a clue, dummy. In order to get 277/480v from the power co. it's gonna be 3 phase. Obviously you have NO conception of how single phase power is derived from 3 phase power.
What do you think a WYE connection is?
I should have known that a moron like you couldn't understand basic electric disribution.
Looks like you're another one of those alt.H(ack)VAC wannbe electrician's........as you are making an ass of yourself over knowledge common to the electrical industry. There is no doubt that you have never done electrical work for a living to make the statements that you have made. Go back to doing machine work and leave the wiring to the sparkies before you kill yourself or someone else.
This is Turtle.
There is no electric company that supplies electric service to any building in the United States which is 480 volt service without it being 3 phase. You can't seperate 3 phase service from 480 volt service for you can't have one without the other.
Now he did go with a drawed out explanation of the services but everybody does get carried away sometimes.
I just can't get your counter point here with your reply. Awwwww.
TURTLE
.........DAMN........I'M IMPRESSED.........
Fuck off, you imbecile--and just see how far you get by calling people names.
The OP never mentioned 277 volts....YOU DID THIS, ostensibly as an excuse to call someone a "dummy".....But if I want 277v though, I certainly dont have to derive it from a polyphase system.....
Again, voltage has nothing to do with it. Single phase is nothing more than a single a/c circuit, you scope it and it alternates between a high and a low voltage.
You only have a single phase.....this is as opposed to a polyphase system....
The voltage can be changed easy enough with transformers--run it here....run it there....isolate it....center tap it, its split phase---but STILL, SINGLE PHASE......makes no differance how it was derived.......use an old telephone crank for all I care......
FWIW, I actually have some motors that run on FOUR and some that even run on FIVE PHASES--commutation is via PWM technology.....
Could be one of the examples above--why dontcha just go ahead and take a wild guess ???
You havent a clue as to what I might or might not understand, and your doing yourself no favors by continuing with the name calling here.
....LOL.....
I was wiring residential and building shortwave radio from scratch at the age of ten years old.......
....AND.....
As to your "alt.H(ack)VAC wannbe" statement--you are really starting to sound a LOT like some of them guys there with this "leave the wiring to the sparkies before you kill yourself or someone else" attitude, no?
...ALSO....
Where *I* live, you dont need a license to do electrical work, it just has to pass inspection--you just can't charge for it with no license.....
I've wired up many, many new services--and I never once been gigged by the inspectors.......
The last one I did was for myself, a 400amp ct single phase setup with a pair of 200 amp panels, each panel also feeding a 100 amp to a 50 hp rotary transformer to generate three phase for the machine shop, this "generated" power being fed into a pair of three phase panels, branch circuits then feeding the machinery.
The rotary units I engineered and wired myself, inside of a pair of hoffman
24x36 cabinets--they're protected with overload contactors and they start at the push of a button, a 220/120v transformer providing control voltage.....if mains power is interrupted for even a split second the entire system drops out in order to prevent possible utility line spikes from damaging the connected load.You can fool some of the people some of the time.....
"Single phase power systems are defined by having an AC source with only one voltage waveform."
Doh!!!
Only point being it doesnt HAVE to come from an electric company is all....
I could bump it up with a transformer, for instance to power a well pump that is fairly far away, then step back down again at the wellhouse.....
Or I can run a small hydropower installation remotey--and easily feed for a fair distance at 440, 440 or even 575 volts, dropping the voltage again at the point of use.....
Or I can fire up my little coleman generator.....there aint no three phase output on that puppy now is there ??? ( though I could easily step this up to be 480v if there was a need )
Single phase simply does not have to come from a three phase source in order to be single phase--yes if it comes from a utility company it has almost certainly been derived from a three phase supply someplace upstream, however this is just fluff when it comes to describing as to what single phase power really is.
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My whole point only being that Mr. "Volts5000" can't handle anyone so much as suggesting he might have given wrong or incomplete information without him going off on a tizzy, because he is such an arrogant know it all.
I seen it before over in alt.havoc and it was so damned easy to bait him into repeating the exact same behavior all over again here it's pathetic.......sheesh--all it took was for me to post "Poor description--two phases ???" to set him off this time.
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