問3題問題~

1. this the only way each appliance can have the same supply voltage

2. because the current can be run from both end, that means the cable double the size.

3. the leakage current will run thought the earth wire back to the ground of the supply system, then will occur an unbalance current on the live wire and the neutral wire, this will detected by the ELCB, then trip the main supply, but the leakage current normally must be bigger than 30mA.