Connection of the 3 phase smart meter without the Neutral (N) phase

The 3 Phase Smart meter can be used in the Delta configuration 3 phase power without N phase. There is various cases - customers from Norway that uses it connected in a 3 phase homes without N phase.


The connection is a little different than usual, basically one of the 3 phases have to be connected to the N connector of the Smart Meter, the other two can be connected on one of the following connections L1, L2 or L2, L3 or L3, L1 (one connection will remain unused like in the example on the left).

In this kind of connection, the there's only 2 measures that will work that is energy (kWh) and total working (W of all the 3 lines summed) and reactive power (var). All the rest of the measurements are wrong (the phase power (W by line) and the flows (current) will be incorrect), because it is not meant for such a connection. The two measurements will be supported in both ways.


Voltage (U1, U2, U3)


Current (I1, I2,I3)


Power – Active (P1, P2, P3 and total P1+P2+P3)


Power – Reactive total        


Power Factor        


Energy – Active power accumulated Import


Energy – Active power accumulated Export   


Energy – Apparent power accumulated total


Energy – Reactive power accumulated total  

It does not matter if the loads are on all three phases - individual single-phase loads (230V) can be arbitrarily connected to any two phases and the smart meter correctly measuring (not a symmetrical load condition)