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foolios

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How is this a balanced circuit with no current in the common/neutral wire?
The book I am reading states:
If R1 and R2 were not in the circuit, there would be no current in the common wire and the load on each side of the common wire would be the same, or as we say, the load would be "balanced". The balanced load is the same as having the load in series across a voltage of 240 volts.



I don't understand what the author is trying to explain. It would appear to me that 240v should be still going across that neutral even without R1 and R2. Why would there not be any current at all going across it without those two resistors?

If someone could elaborate this further, I would really appreciate it.

Thank you so much in advance.
 
D

desertbootz

  • Thread Starter Thread Starter
  • #2
240V across N (Neutral) and what?

There is 240V between T (Top) and B (Bottom) but only 120V between either B or T and N!

The piece is expecting you to take it that current is effectively flowing from T to B, N is almost superfluous (assuming we aren't trying to rate the supplies, VD under load, etc.) If you remove R1 and R2 (which are in paralel between B (bottom) and N (neutral)) then all you have are R3 and R? (that unlabelled dude at top-right of diag.) in series in a 240V cct.

Try imagining it as a DC cct (which it might be, it shows no preference) with two cells where T -ve is connected to B +ve, that is a battery!

If you redraw the circuit and use two lines for N, one for each 120V you'll see that the R3 and R? do present balanced load to the circuit as a whole.
 

ian.settle1

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Mentor
Arms
Bear with him as he is from the USA and they do things a bit different over there as they do in Canada.

Speaking to a guy I worked with lighting and such is acrss a single phase and neutral but when it comes to equipment that takes a lot of power as in a washing machine they go across two phases and neutral as he has shown in the drawing.
 

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