Provided is an apparatus and method for protecting against unsafe electric current conditions. A protections circuit may be used in a device, 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.

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.

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.

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.

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 device for detecting and potentially eradicating a leakage voltage from a water body comprises at least one wire sensor probe to receive the leakage voltage in the water body. The device comprises a voltage sensing circuit operable for receive the leakage voltage, and generate a voltage signal based on the leakage voltage. The device comprises a trigger circuit to receive the voltage signal, based on magnitude of the voltage signal being greater than a predefined threshold value. The trigger circuit activates an alarm circuit, and activates a circuit breaker. The circuit breaker, in response to activation of the circuit breaker, disconnects a power supply from the at least one voltage source immersed in the water body, thereby eradicating the leakage current from the water body if the leakage voltage is caused by the activated circuit breaker. The alarm circuit, in response to activation of the alarm circuit, alerts a human being about presence of the leakage voltage in the water body.

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.

Techniques are disclosed relating to electrical safety systems that may be useful, for example, in electromagnetic geophysical prospecting. Electromagnetic streamer systems often include a number of electrical loads in series that are powered by a constant-current power supply unit. Known techniques for detecting electrical faults have various drawbacks in such an arrangement. Embodiments of this disclosure may be used to mitigate some or all of such drawbacks.

In a circuit breaker arrangement, this disclosure describes a method and circuit design enables a current transformer to be used to detect ground faults in circuit breakers (such as a main-tie-main circuit breakers) that have been designed to receive signals from Rogowski coils.

Sampling for arc-fault detection, ground-fault detection, and grounded-neutral fault detection uses a single analog-to-digital converter (ADC). The arc-fault and ground-fault sampling occurs at regular sampling periods that are relatively short com pared to the time between them, thus allowing grounded-neutral fault sampling to occur before and/or after one of these sampling periods. A predefined event may be used to ensure the grounded-neutral fault sampling occurs immediately before and/or after one of the periodic sampling periods. The predefined event may be the expiration of a timer or the time for a sinusoidal signal in a ground fault sense circuit to make a predefined number of zero-crossings. This avoids interference between the arc-fault sampling, the ground-fault sampling and grounded-neutral fault sampling, allowing a single ADC to perform all samplings concurrently. The timing of the predefined event may be periodically reset to compensate for any changes due to temperature and/or over time.