I have observed that residential buildings receive 3 phase supply, even though almost all appliances are single phase input type. The phases are split into three separate lines and loads are evenly distributed on all of them. Something like this except the 3 phase motor which has been shown in this image:
Even though the lines are split inside the building, I think that a 3 phase energy meter is installed at the incoming point for energy metering purpose (please correct me if I am wrong).
My question is – If I use 3 X single phase energy meters for all three lines, will it give me the total energy consumed in the building as recorded by the 3-phase meter?
The plan is to measure energy at switchboard level to collect some stats for high energy consumption points. The switchboard will contain single phase appliances like fan, tubelight, CFL light, socket, TV etc. However this will make sense only if energy recorded by main meter is equal to sum of energies recorded by individual switchboards. Ignoring some losses in wiring. 5% accuracy is good enough for me.
Best Answer
Yes.
The sum of the power in the individual phases will equal that in the 3 phase feed.
There may conceivably be some interesting results, such as if a 2 wire connected phase to phase load is used, or several thereof, but the end result should (will) "balance.