Systems and methods for data center operational monitoring are disclosed. In at least one embodiment, one or more automated cable repair units to be directed toward a cable failure to identify a cable associated with the cable failure and to determine a corrective active to repair the cable failure.

An input sensor short-circuit inspection method including: setting an inspection frequency for detecting a short-circuit of an input sensor comprising a plurality of electrodes; driving the input sensor in an inspection mode at the set inspection frequency; and detecting the short-circuit of the input sensor based on a capacitance charged between adjacent electrodes among the plurality of electrodes of the input sensor in the inspection mode.

An input sensor short-circuit inspection method including: setting an inspection frequency for detecting a short-circuit of an input sensor comprising a plurality of electrodes; driving the input sensor in an inspection mode at the set inspection frequency; and detecting the short-circuit of the input sensor based on a capacitance charged between adjacent electrodes among the plurality of electrodes of the input sensor in the inspection mode.

A diagnostic system includes a fan control circuit coupled to an electric fan and a microcontroller, and a sense line coupled to the fan control circuit and the microcontroller. The fan control circuit outputs a fan command sense signal at a duty cycle through the sense line to the microcontroller. A tachometer generates a tachometer signal at a frequency indicative of the rotational speed of the electric fan. A fan tachometer circuit receives the tachometer signal and outputs the tachometer sense signal at a frequency to the microcontroller in response to the tachometer signal. The microcontroller sets a second diagnostic flag to an error value indicating that the sense line has impaired operation if the frequency of the tachometer sense signal is within a desired frequency range, and a first diagnostic flag is equal to a first error value.

A diagnostic system includes a fan control circuit coupled to an electric fan and a microcontroller, and a sense line coupled to the fan control circuit and the microcontroller. The fan control circuit outputs a fan command sense signal at a duty cycle through the sense line to the microcontroller. A tachometer generates a tachometer signal at a frequency indicative of the rotational speed of the electric fan. A fan tachometer circuit receives the tachometer signal and outputs the tachometer sense signal at a frequency to the microcontroller in response to the tachometer signal. The microcontroller sets a second diagnostic flag to an error value indicating that the sense line has impaired operation if the frequency of the tachometer sense signal is within a desired frequency range, and a first diagnostic flag is equal to a first error value.

A method capable of effectively detecting an earth state and an electrical apparatus using the same are provided. The electrical apparatus includes a first detection unit for detecting whether there is power between a power supply line L and an earth line G and outputting a first detection signal, a second detection unit for detecting whether there is power between a neutral line N and the earth line G and outputting a second detection signal, and an earth state determining unit for determining an earth state according to the first detection signal and the second detection signal and determining whether a power supply is connected in a normal phase or a reversed phase.

A method capable of effectively detecting an earth state and an electrical apparatus using the same are provided. The electrical apparatus includes a first detection unit for detecting whether there is power between a power supply line L and an earth line G and outputting a first detection signal, a second detection unit for detecting whether there is power between a neutral line N and the earth line G and outputting a second detection signal, and an earth state determining unit for determining an earth state according to the first detection signal and the second detection signal and determining whether a power supply is connected in a normal phase or a reversed phase.

A protection circuit is disclosed. The protection circuit includes a direct current (DC) blocking component electrically connected between a neutral of the transformer and a ground, and an overvoltage protection device electrically connected in parallel with the DC blocking component. The overvoltage protection device is constructed to repeatably and reliably provide overvoltage protection in response to a voltage at the transformer neutral above a threshold. The DC blocking component has an impedance below a predetermined value, thereby effectively grounding the neutral of the transformer. The DC blocking component is persistently maintained in connection to the transformer neutral.

A method for identifying a malfunctioning current sensor in an electrical apparatus, in which an electrical power supply of the electrical apparatus is at least partly supplied by a switched-mode electrical power supply circuit connected to at least one current sensor which samples an electrical current in a phase conductor of an electrical installation, the power supply circuit delivering a regulated electrical voltage, the method including: determining a switching duty cycle of a power switch of the switched-mode electrical power supply; analysing the determined switching duty cycle; and identifying a failure condition if the behaviour of the switching duty cycle is representative of a malfunctioning of at least one of the current sensors.

A ground-fault detecting device includes: a first detecting module, having a first input terminal, a second input terminal, and a third input terminal coupled to a first-phase electric power, a second-phase electric power, and a third-phase electric power on an AC side of a photovoltaic power generating system respectively, for sampling voltages of the first-phase electric power, the second-phase electric power, and the third-phase electric power to generate a first sampled voltage, a second sampled voltage, and a third sampled voltage respectively; and a controller, coupled to the first detecting module, for determining if a ground-fault occurs in the AC side before the photovoltaic power generating system is connected to a grid according to the first sampled voltage, the second sampled voltage, and the third sampled voltage; wherein the controller generates an alarm signal when the ground-fault occurs in the AC side.