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.

A DI-circuit breaker device includes a summation current converter for detecting fault currents in a phase conductor and a neutral conductor, and a detection device for detecting fault states of a protective ground conductor. The detection device detects the presence of a phase voltage on the protective ground conductor as a fault state. The detection device has a capacitive sensor which, when touched by a user, forms an electric capacitor with an impedance relative to ground potential. The detection device further has evaluating electronics adapted to determine a phase position by connecting the sensor to the phase conductor and, separately therefrom, to the neutral conductor. The evaluating electronics determine the absence of a phase voltage on the protective ground conductor when there is no voltage between the neutral conductor and the protective ground conductor when phase is present at the phase conductor. Further, a corresponding operating method is described.

A load drive circuit includes a power source terminal (“PST”), a power source and a load terminal connecting a load to the power source. A semiconductor switch connects the PST to the load terminal. A control circuit includes an output terminal for opening/closing the semiconductor switch. A freewheeling circuit includes a freewheeling diode and a protection switch blocks a current from the power source to the semiconductor switch when the power source is connected in a reverse manner. A first terminal connects the control circuit to a first fixed potential and a second terminal connects an anode of the freewheeling diode to a second fixed potential. A connection circuit includes a connection switch connecting the output terminal and the first terminal. The connection circuit connects the output terminal to the first terminal when a rise in a potential difference between the first terminal and the second terminal is detected.

A fault protection arrangement. The fault protection arrangement may include a neutral grounding resistor including a first non-ground end, connected to a neutralizing point, and a second non-ground end. The fault protection arrangement may include a neutral grounding resistance monitor assembly, directly coupled to the second non-ground end of the neutral grounding resistor. The neutral grounding resistance monitor assembly may include comprising a signal source coupled to the neutralizing-point; a first current sense circuit coupled between the signal source and the neutralizing-point; a first voltage sense circuit coupled between the signal source and the neutralizing-point; a second current sense circuit, comprising a current sensor, coupled between the second non-ground end of the neutral grounding resistor and a protective earth connection.

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.

Electric vehicle supply equipment has a test circuit configured to be switchable from a first test mode to at least a second test mode. In the first test mode, the test circuit is configured to measure a first voltage difference between a live terminal and a neutral terminal, a second voltage difference between the live terminal and a reference ground terminal and a third voltage difference between a circuit protective conductor terminal and the reference ground terminal and to disconnect a charging supply if at least one of the first, second and third voltage differences exceeds a respective voltage limit. In the second test mode, the test circuit is configured to measure the first voltage difference and to disconnect the charging supply if the first voltage difference exceeds a respective voltage limit and not to disconnect the charging supply in response to any test of the second or third voltage differences. The voltage limit for the first voltage difference is configured to be greater in the first test mode than in the second test mode.

A system for monitoring the integrity of a plurality of ground conductors has a plurality of monitors, with a different monitor associated with each ground conductor. Each monitor includes a voltage sensor which monitors voltage on a closed circuit of the monitor. Upon the voltage sensor sensing an unexpected voltage, a transmitter of the monitor issues an “alarm” signal, which may be wireless (e.g., being sent using LoRaWAN protocol). The transmitter may issue other signals, including a periodic “heartbeat” signal to confirm continued operation of the monitor, and a “movement” signal to indicate movement of the monitor. The monitor may be GPS-enabled, in which case each signal may include the GPS coordinates of the monitor. The signals issued by the transmitter may ultimately be analyzed by an operator via a user interface platform, which may simultaneously display information regarding two or more of the plurality of monitors.

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 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.

A circuit for ground disconnection protection is provided herein. In an embodiment, the circuit includes power transistor elements in a common-source arrangement coupled between a first ground and a second ground. The power transistor elements are configured to turn on during a ground disconnection event in an electric motor system. This allows a current to pass between the first ground and the second ground, bypassing a control circuit.