The present disclosure provides a method and system for mounting a current transformer in proximity to a circuit breaker of an electrical system. Generally, a sensor assembly contains a plurality of current transformers (CTs) for measuring power wires from a main power supply. To accommodate measuring a greater number of wires than one sensor assembly can service, a plurality of sensor assemblies can be mounted end-to-end. The sensor assemblies can have symmetrical recessed portions that laterally align when mounted end-to-end by inverting one of the sensor assemblies. The lateral alignment allows CTs mounted lateral to the recessed portions to be aligned with corresponding circuit breakers, so that wires passing from the circuit breakers are aligned with the CTs, reducing bending stresses on the CTs in contrast to prior efforts. Changes in polarity caused by the inversion can be adjusted by software, firmware, hardware or a combination thereof.