The Crestron Green Light® GLS-EM-CTI is a current transformer interface designed for use with a GLS-EM-MCU Crestron Green Light Power Meter Control Unit. The GLS-EM-CTI current transformer interface, in conjunction with the main control unit, facilitates monitoring of multiple branch circuits. This allows users to monitor the power consumption of a particular area or device. GLS-EM-CT current transformers are placed around the feed wire of each circuit, and then connected to the GLS-EM-CTI current transformer interfaces. As many as four (4) GLS-EM-CTI units can connect to a single GLS-EM-MCU power meter control unit for monitoring of up to 84 branch circuits.