Motor controlsQuestion 6 of 1506

What is the typical secondary voltage range of a potential transformer that feeds a protective voltage relay?

0 to 5 V AC
0 to 120 V AC
0 to 600 V AC
0 to 24 V DC

Show answer

Correct answer: 0 to 120 V AC

Potential transformers step the high monitored voltage down to about 0 to 120 V AC.

Source: Lessons in Electric Circuits IV: Digital (Kuphaldt), 5.4: Protective Relays

Questions last reviewed: 18 October 2026

Red Seal Electrician Practice needs JavaScript to run. Use its questions for practice. The real pass mark is usually 70%. Check it with your province or territory's apprenticeship office.