In residential applications, ground fault sensing is used to protect a building’s occupants from electric shock. Everyone is familiar with the ground fault interrupter (GFI), incorporated into a duplex outlet, that quickly opens the circuit when a fault is detected. The National Electric Code mandates their use in kitchens, bathrooms and other wet locations. To provide a high degree of protection in these areas, the trip limit is set at 6mA by national safety standards. While operator safety is important in industrial settings, ground fault sensing is also used there, with different limits, to protect equipment from damage. (more…)