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Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ.

RE: please teach me...


There is a reason power companies use balanced lines to transmit power to your house.

I assume you are speaking of the 240/120V nominal secondary winding output of the utility power transformer.

The power company in my area sends out 3 phase 4 wire WYE power from the substation to an area intended for 3 phase as well as single phase power.
In residential areas one hot phase and the neutral, (the earth grounded Conductor), are used to feed step down utility power transformers to feed residential dwelling units. The secondary side of the transformer is single phase 240/120V. It is called a split phase winding. You could say balanced power, 120V - 0V - 120V.

Only the imbalanced load of Line 1 to Neutral and Line 2 to neutral returns on the service entrance neutral to the transformer neutral. The balanced load is in series with Line 1 and Line 2.
Example, if at the main service electrical panel Line 1 to neutral load is 10 amps and line 2 to neutral load is 10 amps then zero amps will return on the service entrance neutral to the transformer neutral. The two 120V 10 amps loads are in series with one another.

The Link below is a great example how a single phase split phase winding works.



Edits: 09/18/16

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  • RE: please teach me... - jea48 09:44:47 09/18/16 (0)


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