Monitoring power-related parameters in a power distribution unit

A power distribution unit comprising:

• a power distribution unit housing disposable in an electrical equipment rack of the type in which a plurality of electrical components are mountable;
• a power input penetrating the housing configured to provide an alternating current (AC) power input to a plurality of power outputs;
• the plurality of power outputs disposed in the housing, each in electrical communication with the power input and each connectable to an electrical load;
• a voltage sensor for sensing a voltage at the power input or at one of the plurality of power outputs;
• a plurality of current sensors each in electrical communication with one of the power outputs to sense current through each of the plurality of the power outputs, the plurality of current sensors disposed within the housing;
• and
• a power monitoring section in electrical communication with the voltage sensor and the current sensors and responsive to signals provided by the current sensors and the voltage sensor to calculate energy with respect to at least one of the plurality of power outputs, wherein:
• the energy that is calculated corresponds to an interval longer than one cycle of AC input power, and
• the energy is calculated by accumulating instantaneous power values, obtained by multiplying a voltage value sensed by the voltage sensor with a current value sensed by at least one of the plurality of current sensors, over the interval.