How should CP systems be maintained to avoid underprotection or overprotection?

• A. Check once every decade
• B. Regular potential/current monitoring, adjust power supply, inspect connections, and verify anode life and coating condition
• C. Only replace anodes when there is visible corrosion
• D. Do nothing

Answer: (A)

Regular maintenance of CP systems hinges on ongoing monitoring and timely adjustments to keep the protective current and potentials in the right range. By routinely measuring the structure’s potential against a stable reference electrode and watching the current being delivered, you can tell whether the system is providing adequate protection. If readings drift, you adjust the power supply to bring the potential back into the desired protective zone. At the same time, inspecting connections and wiring ensures there’s no high resistance or loose joints that would waste current or create uneven protection. Checking the life of the anodes and the condition of the coating is essential because worn anodes or degraded coatings change how and where protection is distributed, potentially leading to underprotection in some areas or overprotection in others. This proactive approach prevents ongoing corrosion and avoids damage that can come from overdoing protection, such as coating disbondment or hydrogen effects. In contrast, very infrequent checks, waiting for obvious signs, or doing nothing would fail to catch changing conditions in soil chemistry, coating condition, or interference from stray currents, which is why regular monitoring and adjustment is the recommended practice.