A ground fault circuit interrupter with a reversed wiring protection function is provided. The ground fault circuit interrupter may include a main circuit switch, a middle layer bracket, a reset button, a trip coil, an electromagnetic trip mechanism, a lifting piece, a locking piece, and an elastic reset mechanism. Sides of the lifting piece may be sleeved upon live line and neutral line metal rods, respectively. Reset springs may be sleeved upon the metal rods. In a correct wiring state, an upper end of the live line metal rod may be in conductive contact with a live line movable metal sheet of the main circuit switch, and an upper end of the neutral line metal rod may be in conductive contact with a neutral line movable metal sheet of the main circuit switch, the movable metal sheets extending from the power load end.

The present invention relates to a protection circuit and a ground fault circuit interrupter. A protection circuit may include a power supply circuit, a ground fault detection circuit, a signal amplifying and shaping circuit, a microcontroller control circuit, a power supply detection and indicator circuit, a tripping mechanism control circuit, and a reverse grounding detection and execution circuit. The microcontroller control includes a microcontroller, a first capacitor, and a reset filter circuit. The reset filter circuit comprises a reset IC, a second capacitor, and another capacitor. A ground fault circuit interrupter may comprise an interrupter body with a protection circuit in the interrupter body. The practice of the present disclosure may address installation safety risks of conventional ground fault circuit interrupters and arc fault circuit interrupter and improve the safety of ground fault circuit interrupters.

An improved GFCI device prevents miswiring. Load conductors are electrically isolated from receptacle conductors. Normally closed contacts are held open by a miswire prevention mechanism, such that if power is connected to the load contacts, power cannot be delivered to the GFCI device, the receptacle conductors or the line conductors. Once power is properly connected to the line conductors, a proper wiring detection circuit activates the miswire prevention mechanism to release the normally closed contacts, thereby electrically connecting the receptacle conductors and the load conductors. After proper installation, the receptacle conductors are preferably permanently connected to the load conductors. The device is preferably shipped in the reset state.

Safety device for an electrical apparatus powered by an AC mains power supply, the safety device comprising: an electric circuit having inputs for connecting to an active, neutral and earth conductors of the electrical apparatus which are in turn coupled to the AC mains power supply, the circuit being operable to: produce and apply a stepped down voltage and current to the earth conductor from the main supply; and electrically isolate the active and neutral conductors from the earth conductor in response to detecting that either: the active conductor is incorrectly wired to the neutral circuit of the AC mains power supply; the neutral conductor is incorrectly wired to the active circuit of the AC mains power supply; or the neutral conductor is switched; wherein one or more solid state relays are employed by the circuit for both producing the stepped down voltage and electrically isolating the conductors from earth.

A GFCI circuit that includes an electronically controllable main switch that can turn on, and turn off, the delivery of electrical power from the GFCI circuit. The main switch is controlled and monitored by a microcontroller unit using at least digital input and digital output signals, and which includes analog to digital converter. The microcontroller unit may also use the on-off functionality of the main switch in connection with repeatable detection of miswiring of the GFCI circuit. The GFCI circuit can further be adapted to conduct a self-test that can temporarily disable the ability of a trip signal generated by a GFCI integrated circuit in response to a test fault to cause the tripping of the main switch. The microcontroller unit further monitors one or more characteristics of the GFCI circuit, including the main switch and trip signal(s), and can determine whether the GFCI circuit has reached its end-of-life stage.

An apparatus for detecting an open neutral condition in a split phase power system is described. The apparatus includes two powered lines providing output electricity to an electrical distribution system and a shared neutral line providing a grounded neutral to the first and second powered lines. The apparatus is configured for detecting when an open neutral condition is present in the split phase power system by determining when a power current is present on one or both of the first and second powered lines while a return current is not present on the neutral line; and in response to detecting that the open neutral condition is present, causing an interrupter to interrupt the power supplied by the first and second powered lines or to generate a signal indicating an open condition.

An AFCI protective system includes a MOV circuit that has a plurality of line terminals comprising at least one phase conductor, a neutral conductor or a ground conductor. A MOV is coupled to a pair of line terminals through a low impedance circuit, and a response circuit configured to activate a human readable indicator when the MOV is experiencing an end of life condition.

Provided is disclosure for embodiments providing surge protection, where the electric load can be isolated from its power supply upon detection of a wiring fault, undervoltage, and/or overvoltage.

Systems, devices, and methods for a transformer including: a first drive winding (206) wound on a first core; a second drive winding wound on a second core; a sense winding wound across the first and second cores; and a compensation winding wound across the first and second cores; where one or more utility lines are threaded through a middle of the first and second cores, a common mode current in the one or more utility lines causes one or more pulses to appear on the sense winding, a current on the compensation winding is adjusted until the one or more pulses on the sense winding are cancelled out, and the common mode current on the one or more utility lines is the adjusted current on the compensation winding multiplied by a turn ratio between the compensation winding and the sense winding.

An auto-monitoring circuit including a first input structured to receive a signal from a processor of a circuit interrupter, a second input structured to receive power from a circuit protected by the circuit interrupter, a first switch structured to remain closed while the signal is received at the first input and remains above a predetermined threshold level and to open when the signal ceases to be received at the first input or drops below the predetermined threshold level, a second switch structured to remain open while the first switch is closed and to close when the first switch opens, and an output electrically connected to a trip circuit of the circuit interrupter. Closing the second switch causes a trip signal to be output to the trip circuit that causes the trip circuit to trip open the separable contacts.