Hi I have a question,


when comparing results with from 2 or 3 watt meter methods, why is it necessary to disconnect the neutral?


Thanks

 

In the two watt meter connection method the two required line-to-line voltages are connected to the potential coils on the individual watt meters. So you don't need a neutral connection. The meter potential coil must therefore be rated for the supply line-to-line voltage.

The three meter method is a 4-wire arrangement with each meter potential coil connected between line (phase) and supply neutral.