A connector for electric vehicle supply equipment includes: a housing that includes one or more electrical coupling members that are connectable between the electric vehicle supply equipment and a mating inlet of an electric vehicle to supply electric power to the vehicle. The housing includes a sensor for detecting light within the housing and outputting a signal in response to a detection of light within the housing to interrupt or disable the supply of electric power to the vehicle through the connector.

In some examples, after a jack of a power supply is connected to a port of a device, a first safety chip may provide a signal that includes an amount of power sufficient to power a second safety chip located in the power supply. After receiving a message from the second safety chip, the first safety chip may send the second chip an instruction to cause relays in the power supply to transition from open to closed, causing power to be provided by the jack to the computing device. The first safety chip may repeatedly send a continue instruction requesting the second chip to keep the relays in the closed position. If the jack is disconnected from the port, the second safety chip fails to receive the continue instruction and causes the relays to transition back to the open position, stopping power from being provided by the power jack.

In some examples, after a jack of a power supply is connected to a port of a device, a first safety chip may provide a signal that includes an amount of power sufficient to power a second safety chip located in the power supply. After receiving a message from the second safety chip, the first safety chip may send the second chip an instruction to cause relays in the power supply to transition from open to closed, causing power to be provided by the jack to the computing device. The first safety chip may repeatedly send a continue instruction requesting the second chip to keep the relays in the closed position. If the jack is disconnected from the port, the second safety chip fails to receive the continue instruction and causes the relays to transition back to the open position, stopping power from being provided by the power jack.

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.

A power system includes multiple power units (PUs), each including a circuit breaker (CB), a local controller (LC) and an intelligent electronic device (IED). For any one of the PUs, the IED, when determining that the CB has mechanically failed, outputs a disconnect message via a network to the IED(s) of the remaining PU(s). For each of the remaining PU(s), based on the disconnect message, the IED thereof, when determining that the corresponding CB is a relevant CB, outputs a trip control signal that indicates to trip for receipt by the corresponding LC, so that the LC causes the CB to switch to an open state.

A power system includes multiple power units (PUs), each including a circuit breaker (CB), a local controller (LC) and an intelligent electronic device (IED). For any one of the PUs, the IED, when determining that the CB has mechanically failed, outputs a disconnect message via a network to the IED(s) of the remaining PU(s). For each of the remaining PU(s), based on the disconnect message, the IED thereof, when determining that the corresponding CB is a relevant CB, outputs a trip control signal that indicates to trip for receipt by the corresponding LC, so that the LC causes the CB to switch to an open state.

An electrical apparatus comprises an earth input (10a) for connection to an earth wire (10) of an electrical supply from a distribution network, an earth interface for providing an earth connection from the earth input (10a) to an appliance (2) and current sensing means (40) for sensing a current flow through the earth input (10a). The electrical apparatus further comprises earth-wire disconnection means (48) for disconnecting the earth interface from the earth input (10a) when a sensed current flow through the earth input (10a) satisfies an earth-wire disconnection condition and live-wire disconnection means (42) for initiating a disconnection of a live wire (4) of the electrical supply to the appliance (2) before or at the same time as the disconnecting of the earth interface.

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 thermosensitive wire includes a pair of conductive wires each covered with an insulator that softens at a preset temperature, and the pair of conductive wires are configured to come into contact with each other to be short-circuited in response to the insulator softening. A power supply system includes: a second power source configured to supply power to the pair of conductive wires; a short circuit detector configured to detect that the pair of conductive wires are short-circuited; a disconnection detector configured to detect that the pair of conductive wires are disconnected; and a controller configured to perform, for power supply to a power supply wire, abnormality control that differs between in the case where the short circuit detector detects that the pair of conductive wires are short-circuited and in the case where the disconnection detector detects that the pair of conductive wires are disconnected.