Abstract: An electrical power meter for monitoring electrical power supplied to a load comprises a meter case, a plurality of current transformers within the meter case for sensing the electrical current in a plurality of line conductors of a power distribution system, and a plurality of pairs of terminals on the meter case for connecting the meter to the line conductors. The terminals of each pair are located on opposite sides of one of the current transformers, and a current transformer bus bar connects the two terminals and extends through one of the current transformers. A plurality of guides adjacent selected pairs of the terminals position lugs connecting line conductors to the selected pairs of terminals.

Abstract: A method of measuring the total harmonic distortion in an electrical distribution system. The distribution system is sampled regularly to generate a set of data. The data is filtered using a narrow band filtering algorithm to measure the energy in fundamental and other harmonic frequencies. Due to the filtering, the energy in harmonic frequencies can be measured without interference from broadband noise, which provides an improvement in the measurement of total harmonic distortion at low current or voltage levels. A method is provided to sum the energy in identified frequencies in a multi-pass configuration, such that only a subset of all monitored frequencies are filtered and summed in each pass, with the balance being filtered and measured in subsequent passes. After all subsets are measured, the total harmonic distortion is calculated.

Abstract: A method of measuring the total harmonic distortion in an electrical distribution system. The distribution system is sampled regularly to generate a set of data. The data is filtered using a narrow band filtering algorithm to measure the energy in fundamental and other harmonic frequencies. Due to the filtering, the energy in harmonic frequencies can be measured without interference from broadband noise, which provides an improvement in the measurement of total harmonic distortion at low current or voltage levels. A method is provided to sum the energy in identified frequencies in a multi-pass configuration, such that only a subset of all monitored frequencies are filtered and summed in each pass, with the balance being filtered and measured in subsequent passes. After all subsets are measured, the total harmonic distortion is calculated.

Abstract: An electrical power meter for monitoring electrical power supplied to a load comprises a meter case, a plurality of current transformers within the meter case for sensing the electrical current in a plurality of line conductors of a power distribution system, and a plurality of pairs of terminals on the meter case for connecting the meter to the line conductors. The terminals of each pair are located on opposite sides of one of the current transformers, and a current transformer bus bar connects the two terminals and extends through one of the current transformers. A plurality of guides adjacent selected pairs of the terminals position lugs connecting line conductors to the selected pairs of terminals.