What must be on and operating at all times for impressed current cathodic protection?

The cathodic protection rectifier is essential for impressed current cathodic protection systems because it is responsible for supplying the electric current necessary to protect the metal structures from corrosion. This rectifier converts alternating current (AC) from the power source into direct current (DC) which is then supplied to the anodes of the cathodic protection system.

For impressed current cathodic protection to be effective, this system must continuously operate: the rectifier needs to be active to maintain the protective current flow. If the rectifier were to fail or turn off, the protective measures would be compromised, leading to potential corrosion of the structures it is intended to safeguard.

While the anode, tester, and sensor are important components in a cathodic protection system, they do not have the same critical operational requirement. The anode exists to discharge the current that protects the structure, but without the rectifier providing the correct current, they would not perform their protective role effectively. The tester is used to analyze the effectiveness of the protection system, and sensors may help in monitoring, but again, without the rectifier working continuously, these components cannot perform their functions adequately.