A leakage current protection device with automatic reset after power outage includes a switch, a power supply module, a leakage current detection module, a self-testing module, a drive control module, and a first reset module. The drive control module drives the switch based on a leakage current signal from the leakage current detection module and/or a self-test fault signal from the self-testing module. The first reset module functions to automatically set the leakage current protection device in a connected state when power resumes after an outage. Another leakage current protection device with manual reset after power outage includes similar components above and also a second reset module, which functions to automatically set the leakage current protection device in a disconnected state when power resumes after an outage; the device can then be manually reset using a reset switch. These two devices can suit different needs of different electrical appliances.

A system and method for detecting and isolating a high-altitude electromagnetic pulse (“HEMP”) along electrical lines electrically connected to a monitored infrastructure so as to protect the monitored infrastructure, the method including a phase unit receiving sensor signals from a plurality of sensors electrically connected to each of the electrical lines, respectively, upstream of and associated with the monitored infrastructure. The method includes determining if the received sensors signals associated with the respective electrical line is indicative of an E1 component of an EMP and, if so, actuating an isolation subsystem in less than 300 nanoseconds to electrically isolate the respective electrical line against propagation against the monitored infrastructure. Determining in real time if received sensor signals is indicative of the E1 component includes a hardware implemented neural network (NN) having algorithms for machine learning (ML) and artificial intelligence (AI) operable to provide instantaneous detection and classification.

A circuit interrupter includes a solid-state switch and a mode control circuit. The solid-state switch is serially connected between a line input terminal and a load output terminal of the circuit interrupter. The mode control circuit is configured to implement a first control mode and a second control mode to control operation of the circuit interrupter. The first control mode is configured to generate a self-bias turn-on threshold voltage for the solid-state switch during power-up of the circuit interrupter, while maintaining the solid-state switch in a switched-off state until the self-bias turn-on threshold voltage is generated. The second control mode is configured to disrupt the self-bias turn-on threshold voltage and place the solid-state switch into a switched-off state.

A virtual electronic circuit breaker having an electrical relay and a control circuit, the control circuit including a load and wire protection (“OC”) detection unit, a microprocessor and a driver. The OC detection unit is configured to monitor a power flow and the electrical relay is effective to control it. The driver is effective to cause the relay to stop the power flow upon receipt of a deactivation command. The OC detection unit is effective to cause the driver to receive a deactivation command if the OC detection unit senses that a short circuit condition or an overload condition exists. The microprocessor of the control unit is configured so as to be capable of, at least, receiving input from the OC detection unit and sending output to the driver.

A non-electric shock protection system and method thereof for preventing an electric shock caused by shielding, absorption, and reduction of a leakage current, and preventing an arc by blocking an external surge. The system includes a multi-functional ground fault portion for leakage current shielding and ground distribution, a noise filter portion for shielding, absorbing and reducing a leakage current at a power terminal L and a neutral line terminal N, a power portion for supplying a power, a main control portion for controlling each portion of the system to output a normal power and control an amount of a leakage current, an abnormal current sensing portion for collecting the abnormal leakage currents and noise current, a pulse width modulation control portion for receiving a power from the abnormal current sensing portion and compensating the power through the amplitude and frequency modulation and a polarity indicating portion

Provided is an apparatus and method for protecting against unsafe electric current conditions. An example method includes accessing a selected operating mode for a heating element of the electric grill using at least one user input device of the electric grill, the heating element connected to a voltage line and a neutral line; measuring, using a temperature probe, a temperature of the heating element; estimating an ambient temperature at a location within a cook box of the electric grill spaced apart from the heating element, the estimation of the ambient temperature based on the measured temperature of the heating element; and using the estimated ambient temperature to determine when a target temperature corresponding to the selected operating mode is reached.

A temporary power delivery system includes a power source, a booth stringer, and a portable GFCI device. The GFCI device is receives current from the power source by a first terminal and delivers current to the booth stringer by a second terminal. An electronic processor of the GFCI device compares a combined magnitude of current flowing through first and second phase conductors of the GFCI device to a magnitude of current flowing through a neutral conductor of the GFCI. The electronic processor also compares a first voltage between the first phase conductor and neutral conductor to a second voltage between the second phase conductor and neutral conductor. A circuit breaker of the GFCI device is opened if a difference between the combined magnitude of phase conductor current and neutral conductor current exceeds a first threshold or a difference between the first voltage and second voltage exceeds a second threshold.

A signal sampling circuit for arc detection includes plural current sensors, plural high pass filter circuits, and an adder circuit. Each of the current sensors is configured to sense a measured current and then generate a sensed voltage signal. One of the high pass filter circuits receives the sensed voltage signal from one of the current sensors and performs high-pass filtering on the sensed voltage signal. The adder circuit performs scaling up, adding, and DC offset on the high-pass filtered sensed voltage signals. Each of the high pass filter circuits is composed of a filter capacitor and a first resistor connected in series with the filter capacitor. The adder circuit is composed of the first resistors, a first operational amplifier, and a second resistor.

A method for processing an interphase short circuit is provided, including: when a two-phase or three-phase interphase short circuit occurs in a line, maintaining a fault phase of the line to be conducted and tripping off the remaining fault phases, and artificially grounding another fault phase connected to the fault phase or directly utilizing an existing grounding point; connecting a neutral point or a charged phase of a three-phase ineffectively grounded power supply system other than the fault phase to the ground, so as to form a closed loop with the fault phase and generate a current, and detecting a current duration by a controlled switch. When a certain controlled switch reaches a trigger condition and cuts off the line, a fault is cleared.

A system and method for persistent monitoring, detecting, and mitigating detecting and isolating a high-altitude electromagnetic pulse (“HEMP”) along electrical lines electrically connected to a monitored infrastructure so as to protect the monitored infrastructure, the method including a phase unit receiving sensor signals from a plurality of analog sensor circuits electrically connected to each of the electrical lines, respectively, upstream of and associated with the monitored infrastructure. The method includes determining, limiting, shunting, and limiting the impinged transient surges and instantaneously indicates locally the status of the monitored parameters using visual and audio sound via a cybersecure optical communication channel supporting a plurality of wavelengths, from which one wavelength is utilized for a one-directional communication and a different wavelength optical signal establishing a controlled temporary two-directional communication for surge protection system maintenance and update.