Clarification/Follow-up by keon14 on 05/14/04 10:51 am:
Hello voiceguy: Thanks for your response. An electrical circuit must be a complete loop. With the neutral wire connected to earth, how is the circuit complete with the generator (source)?
Jerome

Clarification/Follow-up by voiceguy2000 on 05/14/04 10:56 am:
The neutral wire, while connected to ground, also returns to the power source (generally a pole-mounted transformer for residential wiring) to complete the circuit. This is important, because the ground itself tends not to be a particularly good conductor, especially when compared to copper wire. Thus there is a complete, two-wire circuit connecting the power source to the load.

In practice, residential power in the U.S. is normally delivered as 240-volt service with the center tap of the transformer grounded and feeding the neutral wire. For lights and convenience outlets in the home, each branch circuit is fed by one side of the 240-volt service plus neutral, which supplies 120 volts. For major appliances such as electric ovens or electric water heaters, the full 240 volts will be fed, and the neutral will be ignored.

In the circuit breaker panel for the house, every other breaker for 120-volt circuits will alternate to one or the other side of the 240-volt feed in order to balance the load on the two sides of neutral. For 240-volt appliances (the oven, range, water heater, etc.), there will be a pair of breakers tied together, because both "hot" leads must be broken to kill such a circuit. For a 120-volt circuit, a single-pole breaker is sufficient to kill the circuit, because the neutral wire -- connected to ground -- is considered &#safe."

Hope this helps.

Clarification/Follow-up by keon14 on 05/14/04 6:48 pm:
Hello voiceguy: I do not get the part (For major appliances such as electric ovens or electric water heaters, the full 240 volts will be fed, and the neutral will be ignored)
Its seem that you have two hot wire with voltage tied to the device(stove for example)
,where is the return to complete the circuit.
Thanks again
Jerome

Clarification/Follow-up by voiceguy2000 on 05/14/04 9:19 pm:
The two "hot" wires are the two ends of the secondary of the transformer feeding your house. The appliance, connected to the transformer this way, will receive the full 240 volts. The neutral conductor plays no role in this, and is ignored. Just imagine a transformer feeding the 240-volt appliances.

The grounded center tap is only used for 120-volt circuits, which get 120 volts because they are connected to one end of the secondary and the center tap, thus getting only half the total voltage. The fact that this center-tap is grounded does not affect the circuit to these 120-volt "customers." Grounding this center tap (which becomes the neutral wire) simply means that a significant amount of money can be saved in wiring the house, because only the "hot" side must be switched by wall switches and interrupted by fuses or circuit breakers.

I realize this is probably confusing without a diagram. Try your best to picture what I am describing.