There are 2 configuration options A) Intuition-lc and B) Intuition-lc (2+1).
With option A the Electricity widget will show the sum of the 3 phases i.e. 1+2+3 - This is intended for true 3 Phase monitoring.
With option B) Plug the main feed Sensor into input 1. Put the other 2 Sensors on the other live cables you wish to monitor and plug into inputs 2 & 3.
The Electricity widget will show the main feed only. The 3 Phase widget will show the individual values for each of the 3 inputs. - This is intended for a single phase system where the overall consumption (Channel 1) already includes energy being monitored on sub circuits 2 & 3.
You can change the configuration type using the Wizard within the web dashboard.