To prevent the occurrence of adverse effects of electrolysis as described above, then the cathodic protection installed electrical circuit as shown in Figure III.64.
The principle of this circuit is to inject the arrival of electric current whose direction is opposite to the direction of the electric current that causes electrolysis effects arise. This circuit uses the cathodic protective plate will be sacrificed because terimakan in the process of electrolysis that occurs. If the plate is depleted terelektrolisis cathodic protection, this plate can be replaced with a new one.
In addition to the electromotive force (GGL) arising between the right and left walls of the condenser as described above, there are other electromotive force occurred, namely GGL contact between copper pipe with an iron wall where the copper pipe is installed. Contact GGL is greater on the right than on the left, because the temperature on the right (t2) is greater than the temperature on the left (t1).
GGI contact will cause an electric current circulating from the right end of the copper pipe to the iron wall right where the pipe is installed, the iron wall to the top and bottom, to the left wall where the copper pipe is installed, the ends of the copper pipe in a place where fitted, ie on the left wall continues through copper pipes back to the right end of the copper pipe attached to the place where the iron wall.
The issue also arises in cathodic protection installations cooling water intake (water intake) or diesel power plant and also at the fuel dock where demolition.
In the long pipe and planted in soil and stream water electrolysis effects such as problems mentioned above could also occurred, given the temperature and chemical situation is not the same along the pipe so that the electric potential difference can arise between pipe sections.
P is the cathodic protective plates. Temperature t2> t1 can occur when the flow of cooling water or because of different pole position to sunlight.