what is single phase and 3 phase

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hi guest!!!

well let me tell you the basic concept first..

its very easy to understand..

consider your college, it has 3 departments.. ok? X,Y,Z

you plan out the power flow in the college in two ways.. 1.) single phase 2.) three phase.

we have to connect these 3 depts. and supply power to them.. ok?

so in a single phase connection it will be good if you see hte diagram in google images or something..

in this case.. consider that the line trips in Y block, this wud result in power failure in all 3 blocks.. and so entire college goes dark!

now plan2.) you have 3 phase.. try referring to the diagrams..

here we have delta and Wye connections.. lets take Wye .. it has three branches branch a, b, and c..

so lets say the power is supplied to X block through branch a, Y nad Z block by branch b and c respt.

so in any case if your chairman happens to visit the Y block . and unfortunately there if a failure in the b branch .. you can easily change or shift the phase and supply a or c branch power to block Y in that case!!!

so if u look at the basics.. 3 phase has 3 number of single phases.. all are shifter from the other by an angle..

they r used for carryin alterntiong currents.. and the current is phase shifted form the other branches...

if you see.. our house hold appliances.. all work on 3 phase power supply only..

guest; the generator will have 3 winding in the rotor or stator slots wound 120 degrees apart, continuing to fill around filling all the slots. this could be a 2 pole,4 pole, 8 pole generator, or x poles. tie the 3 starting ends of each wire & tag it L0, tag the other wires L1,L2,L3, say we put the right number turns of wire in the slots, and spin the generator at he right speed, measured the voltage from L0 to L1 or L2 or L3 it read 120 volts, this would give use 3 120 volt single circuits, and the generator slots petty much filled with wire, as bonus we also have a 3 phase 208/120 volt unit. a single phase 2 pole generator would have one half the slots filled with wire, & the other half also filled. when starting to wind in the slots you would fill slot 6 & 8 , with 10 turns of wire, moving to slots 5, & 9, with 9 turns of wire, moving to slots 4, & 10, with 8 turns of wire, moving to slots 3 & 11, with 7 turns of wire, slots 2 & 12,with 4 turns, alots 1 & 13,with 2 turns of wire, now going to the other half of the rotor, or stator, starting with slots 21 & 23, filling those slots with 10 turns of wire, going to slots 22, & 24, filling with 9 turns of wire, slots 21, & 25, filling with 8 turns of wire,slots 20 & 26, filling with 7 turns of wire, till you get to slots 16 & 30 with 2 turns of wire. this would give you a single phase generator if the turns & speed were right. NOTE that not all these slots were filled with wire to their capacity , a waste, this should give you a nice sine wave output for an example of a 120 volt single phase generator. a 3 phased would have filled the slot closer to capacity, perry

In single phase, all the load current is carried by one conductor whereas, in 3 phase the load current is distributed amongst three separate conductors. It is more economical to use three separate smaller conductors rather than a large single one. Also, the instantaneous voltage on each conductor of a three phase system is shifted creating a rotational field when applied to three separate windings of an electric motor. Hope this helps.

I love it - it is such a nice way co confuse the young man with so many informations, all not strictly correct each having a sniff of truth in it.

By the way Mr guest (not Guest. ) are you still at it ? think why there are no 2 phase or 4 phase ? (I will leave out the zero- or should I ?)

ha ha .. yeah .. guest just seems to have disappeared !!!