ECN Forum Forums General Topics of the Trade General Discussion Area Humming in Cubicle of Medium Voltage Switchgear

Surely, listen for popping, or cracking sounds produced by electrical discharges also humming sounds or vibration produced by quality. With lights out, look for blue or purple corona halos. Orange or red sputter arcs are created by intermittent sparking. Best way is you cannot blackout a graphic checkup with a halo.