Mark_R
Member
The article confused things by saying "The neutral connection is provided to prevent an open circuit from shutting down power to everything in case of a failure in one branch. It provides an either/or path."
Yes, that's true, but not the most important function which is to SOLIDLY ANCHOR THE SYSTEM TO A 0V (GROUND) REFERENCE POINT.
The neutral would have zero current only when the load on both 120v legs it equal, which generally is never the case. Any imbalance FORCES current flow on the neutral. Since the neutral is solidly tied to the center tap of the winding (and ground) it has to stay at the 0 volt potential, but the result is current flow on the neutral equal to the DIFFERENCE between the two legs. Kind of like how a zener diode regulates voltage, once the zener voltage is reached, the potential cant climb any more, the harder the circuit tries to drive the potential up, the more current the zener has to pass.
Yes, that's true, but not the most important function which is to SOLIDLY ANCHOR THE SYSTEM TO A 0V (GROUND) REFERENCE POINT.
The neutral would have zero current only when the load on both 120v legs it equal, which generally is never the case. Any imbalance FORCES current flow on the neutral. Since the neutral is solidly tied to the center tap of the winding (and ground) it has to stay at the 0 volt potential, but the result is current flow on the neutral equal to the DIFFERENCE between the two legs. Kind of like how a zener diode regulates voltage, once the zener voltage is reached, the potential cant climb any more, the harder the circuit tries to drive the potential up, the more current the zener has to pass.