. Journal of electricity, power, and gas . iple of operation is iden-tically the same as that previously explained for twosingle phase meters, except that in the case of thetwo single phase meters, the algebraic sum of thetwo registers is taken to obtain the total power, whilein the case of the polyphase meter this is automaticalh-accomplished by having the two discs connected toone shaft. The polyphase meter has the advantageof being easy to read and install. The polyphase meter for use on three phase fourwire S3stems when used without current transformersis of somewhat diiTerent construction
. Journal of electricity, power, and gas . iple of operation is iden-tically the same as that previously explained for twosingle phase meters, except that in the case of thetwo single phase meters, the algebraic sum of thetwo registers is taken to obtain the total power, whilein the case of the polyphase meter this is automaticalh-accomplished by having the two discs connected toone shaft. The polyphase meter has the advantageof being easy to read and install. The polyphase meter for use on three phase fourwire S3stems when used without current transformersis of somewhat diiTerent construction from the meterused on three phase three wire, or on two phase sys-tems. In the three phase four wire meter without cur-rent transformers, it is necessary to have a currentwinding in the meter for each phase. These wind-ings are arranged on the two elements in such a man-ner that the current in one phase passes through awinding on each element: the current in each of theother two phases passing through a winding on one /V^oy^tf/-- So(/rcc. element. Fig. 40 shows the vector diagram and alsothe diagram of connections of this tjpe of meter, inwhich I, r and I represent the currents in phases i, 2and 3 respectively, and l-n, 2-n and 3-n represent thevoltages between the legs i, 2 and 3 and the neutralwire, n. One element of the meter has the voltage 3-nimpressed upon its potential winding, and the currentI passing through one set of current coils, and thecurrent I passing through the other set of currentcoils. The other element has the voltage l-n im-pressed upon its potential winding, and the current, Ipassing through one set of current coils, and the cur-rent r passing through the other set. A three phase four wire system is, in effect, threesingle phase systems, the current in each system Ijeingthe current in the corresponding phase, and the volt-age of each system being the voltage between thecorresponding phase and the neutral. With the connections described above, the powerbe
Size: 2264px × 1104px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookidjo, booksubjectelectricity
