What is Impressed Current Cathodic Protection System Consist Of?

Apr 13, 2021

What is an Impressed Current Cathodic Protection System Consist Of?

Impressed current cathodic protection systems are capable of operating at significantly higher current density, it can work in any resistivity electrolyte such as soil,  freshwater seawater, etc. Once installed, it only requires annual system checks. Instead, galvanic systems require frequent replacement.
Generally, an impressed current cathodic protection system consists of DC power, MMO anode, reference electrode, junction box, and so on.
Direct Current Power:
Impressed current cathodic protection system requires DC power. It is commonly obtained from transformer-rectifier units that step down AC power and convert it to DC power. However, DC power may be available from other sources such as solar cells and others. Units should be designed and manufactured to provide continuous dependable power for design life, which can be 20 years. Proper protective and monitoring devices, including disconnect switches, circuit breakers, output voltmeters, output ammeters, and surge, lightning, and overload protection should be provided. Units should be either manually or automatically controlled over the full voltage output range.

Impressed Current Anodes:
There are two types of anodes that can be considered for ICCP systems: mixed metal oxide anode and high silicon cast iron anode. Mixed Metal Oxide (MMO) Titanium anodes represent one of the most advanced technologies applied in Cathodic Protection.
These anodes are characterized by a wide application range (soil, fresh and saltwater, carbonaceous backfill, concrete) and an extremely low consumption rate in the order of 1 mg/year.
MMO Titanium anodes are composed of a substrate of pure Titanium, chosen for its lightweight, strength, and mechanical properties that make it easy to be worked in many shapes like wires, tubes, ribbon, and grids.

Reference Electrodes:
Permanent reference electrode lead wires should be brought to the rectifier location to facilitate readings. Reference cell wiring shall not be routed through the same conduit used for system DC wiring. Probe type, silver-silver chloride reference electrodes can be installed into the pipeline for measuring water to pipe potential. 

Junction Boxes: Positive and Negative junction boxes shall be required to terminate the anode cables and cathode cables into the respective JB’s.
Cabling: Positive & negative cabling is required to complete the system circuit.

Entrance & Exit Fittings: Fitting consists of a carbon steel or stainless steel pipe section ready to weld to the water pipeline, PVC flange set, entrance fittings. 
Miscellaneous Components: Other items necessary to complete the installation.