Method for accurately determining power usage in a two phase circuit having both two phase and single phase loads

Abstract

The present invention provides a method for accurately determining the power usage on an unbalanced two phase electrical circuit having both two phase and single phase loads using a single current transformer (CT). The method includes a learning algorithm stored in a memory of a monitoring device, the algorithm configured to be implemented by a processor. The learning algorithm determines whether the CT is monitoring the conductor that supplies the single phase load and alerting the installer if it is not monitoring the conductor supplying the single phase load. Upon determining that the CT is monitoring the conductor that supplies the single phase load the learning algorithm will learn the characteristics of at least the single phase load and store the learned characteristic in a memory associated of the monitoring device. The monitoring device also includes a run algorithm that accurately determines the power usage of the two phase circuit by monitoring and recording the current drawn by loads on the monitored conductor and calculating, from the monitored current and the learned characteristics of the single phase load, the power consumed by the unbalanced two phase circuit.