Electrical principles tell us that some electrical devices in the conversion of energy to create a transformation of the environment, such as: electric motors, transformers, such as the first to build a magnetic field to make energy conversion, and some electrical devices to build an electric field before the energy conversion. The electricity required to build a magnetic field and an electric field is reactive power. The meter that records this power is a reactive power meter. Reactive power in the electrical device itself is not to consume energy, but will produce reactive currents in the electrical circuit, the current in the line will produce a certain loss. Reactive POWER Meter is a special record of this loss, generally only the larger electricity units installed such meters.