As it is clear from the name provided 'Bivector', it records kWh and kVAh consumption along with maximum demand on both or on any one as needed. The working principle of kWh element is as commonly described. But the kVAh element is an independent unit and the recording of kVAh is made proportional to the arithmetic sum of kVAh in the three phases. A principle of kVAh meter is in which line currents are rectified to DC current and this DC current is fed to the control winding of a transducer. The kVAh element always records in forward direction irrespective of PF lagging or leading. Therefore, it provides the average PF of the installation.
In the case of bivector, if the PF is a leading one, kVAh element records in forward direction and the average PF is always display as lagging one. Over compensation does not help as it would record more kVARh, thereby the power factor if computed would be extremely low. The consumers' PF so arrived is less than the prescribed limit, and he is liable for penalty for low P.F. In this respect bivector meters might be of significance but results in penalizing the consumer, if compensation is not varied along with varying loads in 24 hours of the day.