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 Question by DavMar Submitted on 10/6/2003 Related FAQ: Electrical Wiring FAQ (Part 1 of 2) Rating: Rate this question: N/A Worst Weak OK Good Great What is the difference between a 220v 3phase power supply compared to a 220v single phase power supply?

 Answer by Jo Submitted on 11/15/2003 Rating: Rate this answer: N/A Worst Weak OK Good Great Simple explanation I hope. If you connect each phase of the 3phase cct via a load to neutral (using 3 separate loads) you have created 3 separate single phase power supplies. Hence the terms 3phase single phase

 Answer by stephen1231 Submitted on 1/21/2004 Rating: Rate this answer: N/A Worst Weak OK Good Great There is a great deal of difference between a three phase and a single phase circuit. Both provide alternating current with the voltage or current following a sine wave that is starting at zero rising to a maximum say 220 volts then decreasing to zero followed by the voltage rising again but in a negative direction or minus 220 volts. In a single phase circuit this just keeps repeating based on the frequency say 60 hertz) that is 60 times a second. In a three phase circuit this occurs with each phase (three) the voltage rising falling going negative and increasing in the opposite direction.  At any instant there are in fact three different voltages impressed on the three wires. To sum it up any device, say motor designed for single phase operation must be used on a single phase circuit.  A three phase motor can only run on a three phase circuit

 Answer by cantyousee321 Submitted on 3/10/2004 Rating: Rate this answer: N/A Worst Weak OK Good Great A three phase is 3 ungrounded conductors (Hot wires)Flowing at 120 electrical degrees apart, 3 alternating currents there are no grounded conductors (neutral wire). A single  phase is 1 ungrounded conductor and 1 grounded conductor.A three phase motor does not need a start or run capacitor because there is 3 currents bombarding the poles in the motor at 120 electrical degrees apart so the magnetic field is strong enough to cause the rotor to make 1 revolution and follow that field.Where as a single phase motor needs a start or run capacitor to get the rotor to spin unless it is a shaded pole or split phase.But that is a question for another day.

 Answer by tadek Submitted on 4/1/2004 Rating: Rate this answer: N/A Worst Weak OK Good Great There is a difference in efficiency also.Single phase Power say 100 amps at 220v would equall(P= I*V) or 220*100=22,000 watts. Now that same current and voltage utilising 3 phase would equall (P=I*V*1.73)or 100*220*1.73=38,060 watts.

 Answer by femi Submitted on 8/1/2006 Rating: Not yet rated Rate this answer: N/A Worst Weak OK Good Great what answer

 Answer by femi Submitted on 8/1/2006 Rating: Not yet rated Rate this answer: N/A Worst Weak OK Good Great the three phase has three sinusoidal wave, while the single phase has a single sinusoidal wave.

 Answer by Nancy Submitted on 10/18/2006 Rating: Not yet rated Rate this answer: N/A Worst Weak OK Good Great Question:  so if a heater I'm interested in buying says we should have 3 phase electricity, I can't use it unless I have 3 phase electricity, then?

 Answer by tattoo Submitted on 2/9/2007 Rating: Not yet rated Rate this answer: N/A Worst Weak OK Good Great also there is less amp needed higher the voltage the low the amp

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