Impressed Current Cathodic Protection
Cathodic protection systems fitted on ships consist of a number of anodes fitted to the hull at selected places below the waterline, and control equipment, which automatically regulates the anode current to the required value (Refer Figures 25.4 and 25.5). Direct current is supplied to the anodes, after transformation and rectification, from the ship's 440V 60Hz 3-(j) distribution system. The control equipment comprises reference electrodes, an amplifier assembly and one or more transformer-rectifier units. There are basically 4 modes of operation namely: 1. The Standby Mode - all output currents are zero. 2. The Manual Mode - the output currents are manually adjustable 3. The Automatic Mode - the outputs vary to provide a constant electrode potential 4. The Configuration Mode - the controller set points may be adjusted
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