Audienceof1
Member
Here's the low hanging fruit for the day for somebody:
Question 501 in the latest Electrical: Power NCEES sample question book asks for the voltage magnitude at the secondary terminals of a single-phase transformer, provided resistive load value (kW), voltage at the load, distance from transformer to load, and the load impedance in ohms/1000'.
I worked it out similar to the examples NEC provides after Chapter 9, Table 9, with the main difference being 3-phase vice single-phase as given in this problem. My question is, why is the voltage drop doubled in the solution? What am I missing here? I'm thinking that in the single phase arrangement, the neutral is a current carrying conductor also and must be included in the calculation, thereby doubling the conductor length. Maybe I should be quiet before I expose more ignorance!
Thanks for the help,
Question 501 in the latest Electrical: Power NCEES sample question book asks for the voltage magnitude at the secondary terminals of a single-phase transformer, provided resistive load value (kW), voltage at the load, distance from transformer to load, and the load impedance in ohms/1000'.
I worked it out similar to the examples NEC provides after Chapter 9, Table 9, with the main difference being 3-phase vice single-phase as given in this problem. My question is, why is the voltage drop doubled in the solution? What am I missing here? I'm thinking that in the single phase arrangement, the neutral is a current carrying conductor also and must be included in the calculation, thereby doubling the conductor length. Maybe I should be quiet before I expose more ignorance!
Thanks for the help,