Impact of the Main Bonding Jumper and the Equipment Grounding Conductor on Ground-Fault Circuit Interrupters

This paper aims to present the appropriate way to implement ground-fault circuit interrupters (GFCIs), so its desired operation is achieved. To do so, the conditions of implementation for proper operation are explained. The focus of this work is to clarify two important terms that have been misunderstood and affect the operation of GFCIs: the equipment grounding conductor and the main bonding jumper. As it will be seen, the misinterpretation of the National Electrical Code leads to an erroneous connection of the neutral conductor to ground on the load side of the electrical system. Such a connection is not necessary but inadequate and only carries the GFCI to trip when unnecessary or vice versa. Moreover, the improper operation of GFCIs implies the rise of costs associated to take the system out of service, yet the use of these devices is essential to protect people from electrocution. Finally, as a plus of this paper, the computational model of a system with a GFCI and the results of its simulation in ATPDraw are presented to show the different cases of proper and improper operation of GFCIs.