Improvements in Transformer-Loss Compensators for Walt-hour and Var-hour Meters

Transformer-loss compensators provide an economical means for metering the loads of utility company customers supplied at transmission voltages on the low-voltage side of the power transformer bank by compensating the watt-hour meter to include the transformer losses in its registration. Improvements have been made in the basic compensator¹ by neutralizing the effect of the flow of meter potential circuit current through the copper-loss compensator. This improves the performance of the compensator, particularly on inductive loads, and makes possible its correct adjustment also for the higher values of losses incurred with var compensation. The burdens imposed by the compensator are sufficiently small to be acceptable in watt-hour metering practice, and for connection to the output side of standard var autotransformers. Under present-day conditions the use of transformer-loss compensators results not only in economies, but also in the conservation of critical materials that would be required for high-voltage instrument transformers on metering installations.