An electrical protection system for protecting an electrical circuit comprising a generator and a plurality of electrical apparatuses, each apparatus comprising a chassis. The protection system comprises a first link associated with each apparatus, connecting the chassis of the apparatus to an earth, and comprising a protection resistor. For at least one electrical apparatus operating under direct current, the associated first electrical link comprises a protection capacitor in parallel with the protection resistor. The protection system comprises a second link connecting a neutral point of the generator to the earth.

An electrical protection apparatus includes at least one first or main electrical protection function able to be carried out by a microcontroller and a button termed a test button intended to be actuated by a user to give rise to the implementation of the testing of at least one second electrical function, this implementation of the test being intended to give rise to the tripping of the protection apparatus D. The electrical protection apparatus includes a device for pooling the actuation of this test button with at least one action intended to carry out a third function, as a function of various types of action exerted on the test button, these actions being detected by the microcontroller, the aim being for the latter to give the order to carry out one of the third functions or else the testing of one of the second functions.

The detection of an insulation fault on a network furnished with tappings by a first monitor can be followed by the location and identification of the fault by way of a locator to be placed on the tappings. To satisfy the level-two security, or SIL-2, in which the risk of occurrence of a hazard is decreased by a factor of greater than 100, second means for detecting the insulation fault are installed, to obtain a redundant item of information as regards the insulation resistance of the network, independently of the monitor but associated with a locator.

An abnormality occurring in a ZCT is detected simply and reliably. A zero-phase-sequence current transformer (ZCT) (11) detects zero-phase-sequence current in power wires inserted therethrough, and in addition to the power wires, has inserted therethrough a wire through which a constant DC offset current flows.

A device and method are provided for interrupting power to a branch circuit and connected load. The device includes a first ground fault (GF) sensor for monitoring a first leakage current across line conductor(s) and grounding conductor of the branch, which ignores leakage current across the grounding conductor, and a second GF sensor for monitoring a second leakage current of the load from the line conductor(s), which takes into account leakage current across the grounding conductor. A processor(s) detects for a GF on the branch circuit based on the first leakage current monitored by the first GF sensor; detects for a GF at the load due to excessive leakage current based on the second leakage current and an allowable/acceptable amount of leakage current for the load; and controls an interruption of power to the branch circuit if the GF on the branch circuit or at the load is detected.

Provided is an apparatus and method for protecting against unsafe electric current conditions. A protections circuit may be used in a device, such as an electric grill, that has one or more electric loads, such as heating elements. The protection circuit may protect against various failure scenarios, including, without limitation, instances of ground fault, over current, driver failure, and failure of a microprocessor. In response to a failure, the protection circuit may trip a latch relay or disable a triac driver to stop current from flowing.

A fault-managed power delivery system for delivering power across a distance with fault management is provided. The system includes a fault management circuitry including a reference resistor having a known resistance, a reference resistor switch, line switches configured to electrically connect or disconnect line conductors, and a controller. The reference resistor switch is configured to electrically connect or disconnect the reference resistor, wherein a duty cycle of switching of the reference resistor switch includes a fault detection portion. The controller is configured to control switching of the reference resistor switch and the line switches. The controller is further configured to determine an impedance of the power delivery system during the fault detection portion, determine a fault condition based on the impedance, and disconnect a line if the fault condition is detected. The fault management circuitry is positioned in the transmitter-side subsystem and/or the receiver-side subsystem.

An electrical wiring device including a ground fault interrupt assembly, the ground fault interrupt assembly comprising a ground fault interrupt circuit, being formed on a first printed circuit board, and a trip mechanism, the ground fault interrupt circuit being configured to detect a differential current between the line conductor and the neutral conductor and to trigger the trip mechanism to electrically decouple the plurality of line terminals from the plurality of load terminals, according to a predetermined criterion, based, at least in part, on the different current; and a USB power supply circuit being formed on a second printed circuit board disposed within the compartment, the USB power supply circuit providing to the at least one USB port, wherein the first printed circuit board and the second printed circuit board are separated by a distance within the inner compartment.

A fault detector detects grounded-neutral faults. The fault detector is configured to: receive a first signal from a first induction circuit, the first induction circuit configured to detect a current imbalance between a line conductor and a neutral conductor; determine a first frequency and a first phase of a noise signal component of the first signal; output a noise cancellation signal to a primary side of the first induction circuit, the noise cancellation signal having the first frequency of the noise signal component and an opposite phase than the first phase of the noise signal component; and generate a trip signal based on determining that an impedance of the neutral conductor to ground is at or below a threshold level based upon the first signal received during the injection of the noise cancelation signal.

The present disclosure is generally directed to a GF detection circuit for use in blenders and other appliances that can detect current leak/GF events and selectively decouple/de-energize components of the blender that could bring a user in contact with dangerous electrical currents. Preferably, a blender consistent with the present disclosure includes at least one ground plane, e.g., in the form of conductive material/sections, disposed on the blender and/or blender jar that act as an input to a GF detection circuit that is at least partially implemented within the base of the blender.