Edison 3-Wire Circuits Flashcards
An Edison 3-wire system has three conductors, what are they?
- 2 ungrounded conductors with equal but opposite potential
- 1 neutral conductor usually at ground potential.
What are three advantages of using an Edison 3-wire system?
- Two different voltages
- Less conductor material
- Less line loss
In an Edison 3-wire system, the neutral conductor carries only the “_____” load.
Unbalanced.
What are the steps required to solve an Edison 3-wire circuit?
- Determine the magnitude and direction of line currents. (Polarities)
- Use Kirchoff’s current law to determine currents at junction points.
- Calculate the line drops in the circuit.
- Use Kirchoff’s voltage law to calculate load voltage drops.
A balanced load is when…?
Equal currents flow through the loads.
There is no neutral current.
In general and ignoring line drops the load with the higher current flow has the “_____” voltage drop across it.
Lower.
What are the effects of a high resistance neutral conductor in an Edison 3-wire system?
The load voltages will be very unbalanced due to the large line drop on the neutral conductor.
How can a high resistance neutral occur?
An improper connection can create points of high resistance.
In a balanced load Edison 3-wire system, what happens to the load voltage drops if the neutral conductor breaks?
Nothing changes since the neutral had no current to begin with.
In an unbalanced Edison 3-wire system, what happens if the neutral conductor breaks?
The circuit becomes a series circuit so the high resistance load will take the majority of the voltage drop.
Would the neutral conductor ever be fused in an Edison 3-wire system?
No, if the neutral is opened on a typical three wire system the voltages could shift to very unsafe values, so they are never fused.
