Polarization Cells are designed to protect personnel and equipment from electrical disturbances. They effectively block cathodic protection DC voltages; all other electrical disturbances are freely conducted to ground, such as:
- AC Fault Currents
- Mitigation of Induced AC Voltages
They contain pairs of pure nickel plates immersed in KOH electrolyte. The surfaces of these plates instantly polarize when separated metallic structures are connected to opposite terminals. The polarizing film blocks DC, to contain cathodic protection current, while freely passing AC. Personnel are safely protected from shock hazards during AC faults. Insulating fittings and equipment are protected during electrical disturbances. Separated underground or submerged metallic structures are efficiently protected.
Isolated structures, which must remain effectively grounded to the AC utility network, are designed to meet this requirement in national electrical safety codes.
SDP supplies polarization cell systems up to 100 kA AC fault current capacities, in 5 kA increments. Each cell system is capable of blocking 1.7 volts DC.