what is conneting delta-delta in system 3 phase?
343720
If i got u rite, it means connecting 2 delta connections together. 3 phrase shd b refering the 3 phrase ac current.\n Not sure if i answered ur question, sorry if i didn't.\n\nbut i think yahoo search shd b able to show u the actual thing
574032
Normal household voltage is 115-120V rms single phase.  A center tapped transformer is used to give you the 115-120V across a pole to centertap or from pole to pole you will see 230-240V. This is all single phase.\n\nFor 3 phase a typical voltage from 2 phases (called line to line) is 208V rms or 480V rms.\nThe 208 is realized by having a "star or Y" setup with the center node as neutral.  Line to neutral is 120V and the 3 phases are 120° degrees apart.  That would mean the Line to Line (LL) is 120*SQRT(3) = 208.\n\nI am not certain why any voltages are specific multiples of 1.1.  The voltages that are commonly used in the USA are 120, 240, 208, 277, and 480 all rms.  Now for transmission purposes, the high side of the transformer voltage should be an integer multiple of one of these voltages.  I do know that transformers typically have integer ratios to either step up or step down the voltage.\n\nHere is some good reading for you:\n\nhttp://www.elec-toolbox.com/usefulinfo/xfmr-3ph.htm\n\nhttp://en.wikipedia.org/wiki/Three_phase_power\n\nBTW, you can become an Electrical Engineer if you know when and where to divide or multiply by either the SQRT(2) or the SQRT(3)!  ;^)
731401
Correct.\nD. when delta G is positive the reaction is non-spontaneous
847868
Are you talking about Distribution transformers ? Then that 3-phase transf. becomes free floating, which means the 'nutral' line receives ALL the phases WITHOUT nutralising them to the Earth reference potential (Standard 0 volts) and hence all the SINGLE PHASE equipment connected to power will experience the 3-phase voltage (up to 440 volts) rather than single phase (about 230 volts). You know what it will do. In case of single phase transformers, and looking at most common load-connection configurations, not much will happen. But you may find more interference on the electronic equipment connected to it.
927155
The addition of a neutral wire with a three phase electrical supply allows a lower voltage, single phase sub-assembly or appliance to be powered by the same line in (one phase to neutral).\nThree phase alone merely conducts between phases.
572836
Three phase power is delivered perhaps to a machine shop with large electric motors.  The motors and transformers (if needed) are often connected in "Y" or "Delta" configurations using all three phases.  The machine shop may also use single phase (for light bulbs?) and two phase (for heaters?).  A single phase to ground provides 110 volts.  Two phase connected together provide 220 volts.  When all three phases are connected 440 volts is provided.  You can often see all three phases up on most power poles and only two phases are connected to most homes (for 110 and 220 volt service).\n\nConsider the analogy between the flow of electric current and the flow of water.  Voltage is like water pressure and current (amps) is like flow rate (gpm).  The three phases represent three different "pipes" between the generator plant and the customer.  Each phase is like a piston pump at the generator that shoves a pulse of water (amps) to the customer then sucks it back (alternating current).  The three phases are connected to the same shaft (like pistons in a three cylinder car) but are evenly spaced (360 degrees/3 = 120 degrees out of phase).  The electrons shoved into the pipe at the generator need not reach the customer before being sucked back.  A like quantity of electrons are pushed into the ground at the customer's installation (communicated at the speed of light!) then pulled back out of the "ground" for reuse.\n\nObviously the power that can be transmitted to the customer depends on whether he/she is using single, two or three phases where P = EI (Power = Voltage x Current).  Hope that helps a little.
200344
W=f.delta(x) \nx=w/f = 49821/717= 69.49 metes
831085
"Three-phase electrical generation is very common. Three separate coils in the generator stator are physically offset by an angle of 120° to each other. Three current waveforms are produced that are equal in magnitude and 120° out of phase to each other."\n\nFrom Wikipedia, the free, online encyclopedia at:\nhttp://en.wikipedia.org/wiki/Alternating_current\n\nMore on three-phase on Wikipedia at:\nhttp://en.wikipedia.org/wiki/Three_phase\n\nFurther links are available on both pages...\n\nHope this helps!
129261
Kilowatts  Equations\nDirect Current  =        I x E/1000\nAC / 1phase 115v or 120v =I x E x PF/1000\nAC / 1phase 208,230, or 240v= I x E x PF/1000\nAC 3 phase All Voltages     =    I x E x 1.73/1000\n\nE = Voltage \nI = Amps \nPF = Power Factor
648766
The other 2 answers are basically right, but Kes has no clue.\n\n3 phase voltages are normally specified by the phase to phase voltage (say 480V).  If a neutral is present from a wye transformer, the phase to neutral may be specified second, such as 480Y/277.  But just saying 480Y means 480 phase to phase in the wye configuration.  The phase to neutral voltage is the phase to phase voltage divided by the square root of 3 (about 1.73).\n\n480V 3 phase is not something to play with.  If you don't know what you are doing, you shouldn't even be in a position to be able to measure the voltage.\n\nTo Kes, normal home wiring is single phase 240/120.  2 phase is a system that existed before 3 phase became standard.  For what you call "440 V" for motors, it would be 440 V between phases.
259954
Delta = Theta x Pi\nGamma = Omega / Alpha ^ Delta\nTheta = Zeta Reticuli * Omega * c^2
148738
Homework, huh?  Badly copied from the source.  Make it an answerable question, clean up the gibberish and try again.  For instance, 90 degrees phase lag at what frequency?  Sorry to be curmudgeonly, but this shouldn't be just about getting answers without understanding.  Anyway, here's a hint.  At 90 degrees, Xr=Xc, and RC=1/(2*pi*f).  For phase lag the R is in series and the C in shunt.
111070
High voltage transmission lines have three line (sometimes two sets of three lines) because they supply three-phase electicity.  The high voltage is reduced in transformers to supply houses.  Houses usually receive power from two of the three phases and the loads on the three phases must be balanced say within a given neighborhood.  Any one phase to ground will supply 110V AC for example to light a light bulb.  The two phases supply 220V AC for clothes dryers and electric ranges and perhaps a central A/C system.  A machine shop with large motors would use all three phases which supply 440V AV.\n\nElectricity can often be compared with the flow of water where pressure is like voltage and current is like flow rate.  For the original old DC electric systems, the generator was like a pump that pushed water through a single line passing it through a light bulb and into the water table (ground).  For a single phase AC system the generator is like a pump the pushes a spurt of water to the house through the light bulb into the ground than sucks a spurt in the reverse direction back to the pump, 60 times a second.  A three phase system is like having three separate water piston pumps on the same shaft that discharge one after the other into three separate lines at 60 spurt cycles a second each.  Obviously the power will depend on the pressure (voltage) and the number of phases (lines) connected to a load.  In addition to the three wires in a three-phase system, there is also a forth wire that ensures a very good connection with the ground (a ground wire).  Both the generator and the house system must be well grounded.  Hope that helps a little.  BTW, a high voltage system often has a fourth wire on top for lightning strikes.
412964
use the delta when you are starting a large motor since it can be hooked to energize only part of the windings of the motor at a time this allows for less amperage to be used to get the thing turning
357873
Fault Currents are calculated based on the impedance of the system. Therefore, by adding line inducatance or even just lengths of wire, the Fault Current can be reduced.\n\nFor a typical 2000KVA, 480VAC 3 phase system a fault current can be more than 350,000amps in less than a second.\n\nCheck out the following: on the 'eatonelectrical' link type in Fault Current for calculations
947411
Depending on the utility company, some use Dyn11 and others Dyn1 or some other vector group that is universal to their\nsystem.\n\nThe reason being is that  they can be interconnected with the low voltage side of another transformer that is connected to the same high voltage supply circuit.\nDyn 11 means that the vector group is at the 11 o'clock position. If for instance two transformers on the same high voltage line side had different vector groups say Dyn11 and Dyn 1 they would always be 30° out of phase, this would mean that should they be interconnected they would immediately trip the incoming CB/fuses.\n\nSource: Electrical Engineer (ret.) with 45yrs experience
199351
I haven't worked with this in a long time and I'm not sure this will work, but try starting w/ this:\n1) Define an equation that describes the " ∞ " with polar coordinates (something like r = C1 - C2*theta);\n2) If L is lengh, delta.L = delta.theta / (2 pi) * r\nand dL = r/(2 pi) dtheta  ;\n3) substitute for r and integrate from 0 to 2pi (or the necessary for one complete " ∞ ".\n \nProbably you'll find more than one mistakes here, but I think the general idea is correct.