>Or does this actually wire inline in the AC circuit being sensed? Yes >I thought these type of sensors were non contact. Internally there is a sensor that measures the magnetic field created by the current being measured. Hence there is no electrical contact between the circuit under test and the measurement circuit. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist