"Real power in balanced (or unbalanced ) 3 phase circuits can be measured by using two wattmeters
connected in any two lines of a three-phase three wire system. In Fig.4(a) the current coils are connected
in lines A and C, with the voltage coil reference connections in line B. The current Ã‚Â°owing through the
current coil of the wattmeter connected in line A is IA and that in line C is IC. Similarly, the voltage
applied to the voltage coils is V ab and V cb (and not V bc) respectively. Their readings will be:"
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