Abstract: The present invention includes an electrical utility meter operable to measure power consumption. The method detects and compensates for one or more wiring errors that affects the power consumption measurement of the electrical utility meter. The method includes the steps of: obtaining measured phase angle data for a plurality of phases in a polyphase electrical system; periodically performing one or more diagnostic tests using the measured phase angle data to determine whether a wiring error is present, automatically adjusting the operation of the electrical utility meter to effect a compensation for the wiring error, said compensation increasing an accuracy of power consumption measurement of the electrical utility meter. The meter is operable to detect and compensate for wiring errors including polarity errors and cross phasing errors. According to another method of the present invention, the meter is operable to determine automatically the service type to which it is connected.