Discovering circuit errors in meter installations

Annual financial losses to energy suppliers caused by connection errors in meter installations should not be neglected. Incorrect connections are often made during installation; these faults are rarely discovered at the time of billing and sometimes go unrecognised for many years. This results in considerable losses to energy suppliers.

At this time of liberalisation in the energy markets correct energy billing becomes even more important, especially because more parties are involved in the process. With the help of an inexpensive and easy to operate portable meter test equipment unit, the errors can be detected during installation, resulting in cost efficiency and less complicated service.

Circuit errors can arise when new meters are installed, when old meters are exchanged for new ones or sometimes even in the course of operation. A paper will be presented at the MATES 99 conference in Birmingham, UK, which analyses the metrological consequences of circuit faults, to find out what effects different circuit errors have on the measurement results on site. An analysis of the behaviour of the meters was undertaken, as well as the values of different electrical quantities in the case of circuit faults. Three-wire and four-wire active and reactive energy meters were tested, and different cases for each were observed.

The new instruments are capable of measuring energy and of evaluating errors of energy measurement by the meter. They also cover additional functions, such as measuring voltages, currents, active, reactive and apparent power (single phase and total), power factors (single phase and total), frequency and phase sequence. The determination of circuit errors is easier if the working standard can display the vector diagram, because the state of the vectors allows conclusions to be drawn which make identification of the type of error more easy.

Connection errors at different meter types can be discovered in the same way. It is possible to detect whether or not an error exists, and if so where it is located, with only a few measurements.