Electronic noise filter protects expensive electronic equipment on board such as Radar, GPS, Sonar, VHF, etc. from overloading and other related problems.
Electronic noise filter protects against overload and other related problems, which are most often caused by overvoltage when the engine is started or during manoeuvres, powerful electrical equipment such as bowpropeller and anchor/electric windlass, as well as atmospheric phenomena. Placed between power supply and the equipment to be protected.