208 v. equipment is a little smaller and cheaper, and 208v. is slightly safer to use. However, 480v. runs on half the amperage 208v. equipment does, which means equipment or devices cost almost 50% less to operate.
With respect to energy consumption, the answer above is incorrect. It is true that equipment that operates at 480v does operate at roughly half the amperage vs. 208v, however, it operates at over twice the voltage. Your local power company charges you per kilowatt hour (voltage x amperage), not on amperage alone.
Example, a 208v motor that draws 10 amps would consume (208v x 10a) 2.080 kilowatts per hour.
The same motor on 480v would draw roughly half, 4.3 amps (480v x 4.3a) and would also consume 2.080 kilowatts per hour.
So in terms of power consumption, they are virtually the same. The main reasons one would opt for higher is the fact that you can install smaller wire and you can run longer distances.
It's a ratio that is directly proportional (at least with electric motors/inductive loads). If you were comparing a 240v motor to a 480v motor the ratio would be exact, if a 480v motor draws 5 amps, the same motor on 240v would draw 10 amps.
There can be an advantage for larger equipment. For the same amount of power delivered, the 480v circuit will have lower current than the 208v circuit, and thus smaller (and less expensive) wire can be used.
your equipment will not run as hot (motors & drives will stay cool)
the higher the voltage the less the amps
so when running circuits to equipment you will be able to run smaller conductors, smaller pipe. It's cheaper
To install high power equipment it is not always feasible to increase the current rating of the equipment.
for a 3 phase system power P = 1.732VI. where V stands for voltage and I stands for current.
Increasing voltage instead of current is more feasible for achieving higher power in most of the cases.
It is the line to line voltage divided by 1.73. 600V / 1.73 = 347V 480V / 1.73 = 277V 380V / 1.73 = 220V 208V / 1.73 = 120V
yes,
1kw=1.25kvaby this relation 75kva=60kwp=1.732*380*I*1I=60000/1.732*380*1I=91AmpsCommentPower factor is irrelevant to this question. You don't need to convert the kV.A rating to kilowatts, simply divide 75 000 V.A by (1.732 x 380). The answer is 114 A.This, of course, assumes that the question refers to a three-phase generator and that 380 V is the line voltage.
Only one neutral conductor is typically in a 3 phase panel.
A 277/480V box should be clearly marked, but not always. The only way to be certain of a box's voltage is to use a voltmeter on it. This type of voltage is very dangerous. When voltages start to get this high, at best you may loose a finger or limb, at worst, you die. I recommend calling an electrician, who will be able to safely check this out.
Not directly, you would need to transform 480v circuit to 120v with a transformer first.
Mathematically, just divide 480 by the square root of three. Electrically, 480V refers to the line-to-line value of a three phase system. For example, measure the voltage across A-phase and B-phase and you'll get 480V. 277V is the line-to-neutral value. Measure the voltage across A-phase and the neutral conductor and you should get 277V.
Standard household and business power in the entire US is 120V single phase and 240V double phase. Light industry will likely use 208V three phase, 240V three phase, 400V three phase, 415V three phase, or 480V three phase. Heavy industry and subway systems use higher AC voltages and sometimes DC.
there isnt a high leg in a three phase 480v panel only on 240v panels
It is the line to line voltage divided by 1.73. 600V / 1.73 = 347V 480V / 1.73 = 277V 380V / 1.73 = 220V 208V / 1.73 = 120V
Line voltage equals phase voltage multiplied by the square root of three. a.k.a. E l = E p X 1.73 In a 3 phase 480v system the phase voltage is 277v. Therefore E l = 277 X 1.73 = 480v
In a star configuration, often called "Y", the voltage across one winding is from a phase to ground. Phase to phase you have voltage across 2 windings. And at the risk of confusing you, the phase to phase voltage is not double the other because the windings are only 120 degrees out of phase and not 180 degrees. To calculate this you take the voltage of one winding, 120v for example, and multiply by the square root of 3, or about 1.732, and get 208v. Or you take 277v and get 480v.
That's 277 volts of alternating current. This is typically one phase of a 480v 3 phase system. Don't worry that 3 x 277 adds up to more than 480v. A 277v line is typically one phase of a 480v 3 phase system.
In a typical 3 phase system you have multiple voltages and configurations that can be used in either single phase or 3 phase, depending on how the circuit is designed. A single phase system is just single phase. You can have multiple voltages but it is always single phase.For example, in a typical 277/480v 3 phase system you can power 277v single phase lighting or equipment, 480v single phase lighting or equipment (which uses 2 legs of the 3 phase system but operates like any other single phase circuit), or 480v 3 phase motors.When comparing motors, a 3 phase motor will be substantially smaller than a single phase motor of the same horsepower. You can also reverse a 3 phase motor by switching any 2 leads. A single phase AC motor runs in one direction regardless of how the leads are connected.AnswerFor a given load, a three-phase transmission system requires less volume of copper in terms of conductor size, compared to single phase, so it is more economical to use three-phase.
At 240v single phase it's 70.8 amps. If it runs on 2 wires plus ground, take the voltage rating of the equipment and divide that into the watts to get amps. At 480v 3 phase it's 25.8 amps. At 208v 3 phase it's 47.2 amps. <<>> There are zero amps in 14 kW. A voltage needs to be stated. I = W/E, Amps = Watts/Volts.
yes,
1kw=1.25kvaby this relation 75kva=60kwp=1.732*380*I*1I=60000/1.732*380*1I=91AmpsCommentPower factor is irrelevant to this question. You don't need to convert the kV.A rating to kilowatts, simply divide 75 000 V.A by (1.732 x 380). The answer is 114 A.This, of course, assumes that the question refers to a three-phase generator and that 380 V is the line voltage.