EWS-CT three phase Current Transformer can be used to monitor one 3-phase load or 3 single phase loads if the load wiring is in the same junction box. The wire that is carrying the load current is simply passed through a hole in the EWS-CT module. There is no electrical connection made to the circuit. The maximum continuous current is 100 amps rms (or 140 amps peak). Surge currents of up to 5 times this value will not damage the EWS-CT but they cannot be read by the EWS-MP.