GB301398A - Improvements in or relating to electric meters and wattmeters - Google Patents

Abstract

301,398. Compagnie pour la Fabrication des Compteurs et Materiel d'Usines Ó Gaz, and Iliovici. A.D. Nov. 28, 1927, [Convention date]. Special quantities, registering; power meters: phase differences, measuring.-Power, energy, or phase meters, are combined with two T-connected or three star-connected auto-transformers provided with tappings for measuring active, reactive, or " complex " power or energy, the connection to the line being either two star or delta voltages, or one star and one delta. The invention is applicable to any polyphase system. In one arrangement, Fig. 6, auto-transformers A, B. C, a four-pole two-way switch D, and a phasesequence indicator E are located in a casing F outside the metering apparatus. The terminals 1, 3 are connected across the lines 1<1>, 3<1>, and the division of the transformer windings is such that by changing the switch connections either active or reactive power or energy can be measured. When " complex " power or energy is required, the transformer connections are re-arranged to give the desired applied voltages. Another arrangement is described for use on three-phase lines having a fourth conductor which is connected to the neutral point of three tapped starconnected transformers. The connections can be grouped so that they connect different line voltages, for example, one set may function on 110 volts and another on 220 volts.