What does a potential transformer measure?

What does a potential transformer measure?

• A. Measures current on high-voltage lines
• B. Steps down voltage to measure low-voltage signals
• C. Measures voltage on high-voltage lines
• D. Converts voltage to current for metering

Answer: (C)

A potential transformer is used to measure voltage on high-voltage lines by providing a safe, scaled-down version of the line voltage. The primary is connected to the high-voltage circuit, and the secondary delivers a low-voltage signal that is proportional to the line voltage while preserving the phase relationship. This isolated, reduced voltage lets meters and protection relays read the voltage safely. It does not measure current—that’s the job of a current transformer—and it doesn’t convert voltage to current itself; it simply outputs a voltage proportional to the line voltage for measurement.

A potential transformer is used to measure voltage on high-voltage lines by providing a safe, scaled-down version of the line voltage. The primary is connected to the high-voltage circuit, and the secondary delivers a low-voltage signal that is proportional to the line voltage while preserving the phase relationship. This isolated, reduced voltage lets meters and protection relays read the voltage safely. It does not measure current—that’s the job of a current transformer—and it doesn’t convert voltage to current itself; it simply outputs a voltage proportional to the line voltage for measurement.