Cable directionality

Audioengr, if I may sidebar and ask a few general questions about things electrical:

1. I current have a 115 volt 20 amp dedicated circuit to my amplifier and the ground has been lifted. I have the schematic and instructions on how to convert my amp to 230 volts. If I install the proper 20 amp duel circuit at the service panel and connect my rewired 230 volt amplifier by simply running two leads (using my currently installed 10/2 romex and obviously from opposing sides at at the service panel), would I need a ground? I know I should always have a ground but I am not using one right now. But all's I need for 230 volts is two 115v lines from opposing phases?

2. If your answer to number one is yes, then why does a 20 amp or 30 amp cooktop or oven have two leads, 1 neutral, in addition to the ground? What's with the second lead in these appliances? Or is it the neutral I should be asking about?

3. You say that the neutral contains the return current as I've heard this many times. But why is it that I can touch my neutral bus in the service panel and not feel a thing? What is different about 'return current'?

-Sparky

Stehno wrote:

would I need a ground? I know I should always have a ground but I am not using one right now. But all's I need for 230 volts is two 115v lines from opposing phases?

No, the ground is strictly for safety. It is not needed in the circuit, however it is well-advised to leave it attached. If you have ground-loops, it is safer to float low-power components to eliminate them, or use an isolation transformer.

why does a 20 amp or 30 amp cooktop or oven have two leads, 1 neutral, in addition to the ground? What's with the second lead in these appliances? Or is it the neutral I should be asking about?

I believe that some appliances use more than two legs from the transformer, or they have internally relays or motors etc. that need 117V with neutral. Not that familiar with appliances.

You say that the neutral contains the return current as I've heard this many times. But why is it that I can touch my neutral bus in the service panel and not feel a thing? What is different about 'return current'?

There is no potential on the neutral bus in the panel because it is referenced to ground there. All neutrals that return to the panel are referenced at a single point. There is a voltage drop in the wire from the component back to the panel, but since the neutral at the panel is tied to the ground at the panel there is no potential on the neutral at the panel. However, if you measure the AC voltage on the neutral at an outlet where there is a load attached, you will measure a small voltage. This is the voltage that is generated across the resistance of the neutral wire from the outlet back to the panel. This voltage on neutral at the outlet will exist only when current is flowing in the circuit. This voltage must be measured with respect to ground.

Thanks, audioengr.