In an impressed current cathodic protection system, the rectifier _______.

• A. Must remain on at all times
• B. Should be turned off during maintenance
• C. May be turned off during low demand
• D. Must be off during non-peak hours

Answer: (A)

Continuous protection relies on a steady supply of DC current from the rectifier to keep the structure at the correct protective potential. In impressed current cathodic protection, the current is injected through anodes into the surrounding medium, making the metal the cathode and suppressing corrosion. If the rectifier is turned off, the protective current stops and the structure’s potential drifts back toward its non-protected state, allowing corrosion to resume. Because protection is lost whenever the current ceases, the rectifier is designed to remain on continuously to maintain ongoing protection. Maintenance can be planned with safety steps, but the normal practice is uninterrupted operation to avoid gaps in protection.