Which statement best describes how to determine a system's identity?

Which statement best describes how to determine a system's identity?

• A. Inspect the bus arrangement
• B. Review protection schemes
• C. Check the impedance of the lines
• D. Confirm the secondary connections of the substation transformer bank

Answer: (C)

Determining which system you’re on comes down to the electrical fingerprint you see at a measurement point. The impedance carried by the line path back to the source is that fingerprint: it depends on line length, conductor properties, and the equipment between the point and the source, so each possible system shows a distinctive impedance profile. By measuring this impedance and comparing it to known values for the potential sources, you can confirm which system is supplying power. Topology or bus layout can show how things could be connected, but they don’t prove which source is active. Protection schemes reveal what devices exist and how they’re set, not which system is currently feeding the bus. The secondary connections of a transformer bank affect voltage transformations, not the identity of the feeding system. So, checking the impedance of the lines provides the most direct, measurable way to determine the system identity.

Determining which system you’re on comes down to the electrical fingerprint you see at a measurement point. The impedance carried by the line path back to the source is that fingerprint: it depends on line length, conductor properties, and the equipment between the point and the source, so each possible system shows a distinctive impedance profile. By measuring this impedance and comparing it to known values for the potential sources, you can confirm which system is supplying power.

Topology or bus layout can show how things could be connected, but they don’t prove which source is active. Protection schemes reveal what devices exist and how they’re set, not which system is currently feeding the bus. The secondary connections of a transformer bank affect voltage transformations, not the identity of the feeding system. So, checking the impedance of the lines provides the most direct, measurable way to determine the system identity.