ACL Type 2

Solid state polarization cells or AC grounding devices are used to mitigate pipeline AC voltages resulting from induction from overhead power lines sharing the same corridor. A main purpose of the AC limiting devices is to protect operating personnel from hazardous touch voltages and second to conduct ac current from the pipeline to soil, lowering the voltage.

Balanced AC limiting An increasingly important task for the AC limiting device is to inhibit AC influenced corrosion by lowering the pipe to soil AC voltage. CP experts throughout have reached agreement that excessive cathodic protection combined with AC voltage is a non-tolerated mixture, likely to cause accelerated AC corrosion. The AC discharge devise has been designed and developed for the purpose of being close to neutral to the DC thus to maintain the rectifier in full control of the cathodic protection level. Unlike other known solid state polarization cells it does not produce additional cathodic polarization by rectifying some of the AC voltage. The unit is used on many ”Energinet” pipelines.