A method and apparatus are for monitoring a secondary power device and for accurately checking a state of the secondary power device, and an electronic system includes the apparatus. The method of monitoring a secondary power device includes setting a first reference parameter by using a voltage of at least one capacitor of the secondary power device, setting a second reference parameter by using the voltage of the at least one capacitor and the first reference parameter, and setting a reference level for checking of the state of the secondary power device by using the second reference parameter, wherein the reference level is used in checking of the state of the secondary power device.

A method and apparatus are for monitoring a secondary power device and for accurately checking a state of the secondary power device, and an electronic system includes the apparatus. The method of monitoring a secondary power device includes setting a first reference parameter by using a voltage of at least one capacitor of the secondary power device, setting a second reference parameter by using the voltage of the at least one capacitor and the first reference parameter, and setting a reference level for checking of the state of the secondary power device by using the second reference parameter, wherein the reference level is used in checking of the state of the secondary power device.

A power meter includes a plurality of terminals for receiving a measure of power consumption of each of one or more phases of power that is delivered to a load and a controller that is operatively coupled to the plurality of terminals. The controller is configured to determine a number of power monitor parameters based on the measure of power consumption of each of one or more phases of power that is delivered to the load. The controller is further configured to operate an interactive menu. The power meter includes a user interface that is configured to display the number of power monitor parameters based on the measure of power consumption of each of one or more phases of power that is delivered to the load and to enable a user to navigate the interactive menu using via one or more screens displayed on the user interface.

A power meter includes a plurality of terminals for receiving a measure of power consumption of each of one or more phases of power that is delivered to a load and a controller that is operatively coupled to the plurality of terminals. The controller is configured to determine a number of power monitor parameters based on the measure of power consumption of each of one or more phases of power that is delivered to the load. The controller is further configured to operate an interactive menu. The power meter includes a user interface that is configured to display the number of power monitor parameters based on the measure of power consumption of each of one or more phases of power that is delivered to the load and to enable a user to navigate the interactive menu using via one or more screens displayed on the user interface.

A monitoring system includes an array of optical sensors disposed within a transformer tank. Each optical sensor is configured to have an optical output that changes in response to a temperature within the transformer tank. An analyzer is coupled to the array of optical sensors. The analyzer is configured to determine a sensed temperature distribution based on the sensed temperature. The sensed temperature distribution is compared to an expected distribution. Exterior contamination of the transformer tank is detected based on the comparison.

An inrush current test device is adapted to receive an alternating current. The inrush current test device includes: a first isolation coupling component, a positive crossing point pulse generation circuit, an output circuit, and a control circuit. The first isolation coupling component includes a primary side and a secondary side, and is responsive to the alternating current on the primary side and conducts the secondary side. When the secondary side transits from an off state to an on state, the positive crossing point pulse generation circuit generates a positive crossing point pulse. When the control circuit is actuated and the positive crossing point pulse is detected, after delaying for a delay time, the control circuit outputs a control pulse for actuating the output circuit for a first operating time. The output circuit is configured to receive the alternating current and output the alternating current when the output circuit is actuated.

An inrush current test device is adapted to receive an alternating current. The inrush current test device includes: a first isolation coupling component, a positive crossing point pulse generation circuit, an output circuit, and a control circuit. The first isolation coupling component includes a primary side and a secondary side, and is responsive to the alternating current on the primary side and conducts the secondary side. When the secondary side transits from an off state to an on state, the positive crossing point pulse generation circuit generates a positive crossing point pulse. When the control circuit is actuated and the positive crossing point pulse is detected, after delaying for a delay time, the control circuit outputs a control pulse for actuating the output circuit for a first operating time. The output circuit is configured to receive the alternating current and output the alternating current when the output circuit is actuated.

An inrush current test device is adapted to receive an alternating current. The inrush current test device includes: a first isolation coupling component, a positive crossing point pulse generation circuit, an output circuit, and a control circuit. The first isolation coupling component includes a primary side and a secondary side, and is responsive to the alternating current on the primary side and conducts the secondary side. When the secondary side transits from an off state to an on state, the positive crossing point pulse generation circuit generates a positive crossing point pulse. When the control circuit is actuated and the positive crossing point pulse is detected, after delaying for a delay time, the control circuit outputs a control pulse for actuating the output circuit for a first operating time. The output circuit is configured to receive the alternating current and output the alternating current when the output circuit is actuated.

An inrush current test device is adapted to receive an alternating current. The inrush current test device includes: a first isolation coupling component, a positive crossing point pulse generation circuit, an output circuit, and a control circuit. The first isolation coupling component includes a primary side and a secondary side, and is responsive to the alternating current on the primary side and conducts the secondary side. When the secondary side transits from an off state to an on state, the positive crossing point pulse generation circuit generates a positive crossing point pulse. When the control circuit is actuated and the positive crossing point pulse is detected, after delaying for a delay time, the control circuit outputs a control pulse for actuating the output circuit for a first operating time. The output circuit is configured to receive the alternating current and output the alternating current when the output circuit is actuated.

A power monitoring system includes a current transformer and a power meter. The current transformer includes a winding for sensing a measure of current in a conductor that supplies power to a load and a machine-readable apparatus that is secured relative to the current transformer and that encodes calibration information that is specific to the current transformer. The power meter includes a first input for receiving the measure of current and a second input for receiving a measure of voltage. A controller configured to receive the calibration information encoded in the machine-readable apparatus, calibrate the controller with the current transformer based on the calibration information and determine a number of power monitor parameters based at least in part on the calibration information, the measure of current sensed in the conductor by the current transformer and the measure of voltage of the conductor.