DOI:10.1049/ji-2.1943.0024

出版商:IEE    

年代:1943

数据来源: IET

摘要:

Electrically-driven mine-drainage pumps may be of the centrifugal or of the positive displacement reciprocating type. Since the characteristics of the driven pump have a considerable bearing on the choice of the most suitable driving motor, the first portion of the paper deals with operating and design characteristics of the two types of pump. The remainder of the paper shows how, by a study of these operating characteristics, the most suitable type of driving motor may be chosen.

DOI:10.1049/ji-2.1943.0025

出版商:IEE    

年代:1943

数据来源: IET

摘要:

The paper gives particulars of some serious damage caused by snowstorms to transmission lines in Ireland and of consequent departures from conventional design. The factors governing the examination of breakdown data are critically analysed and the data and conclusions for particular cases are briefly stated. Loadings are compared with those specified by the British Regulations for Overhead Lines, and the effectiveness of the universal method of controlling the factor of safety of conductors is challenged. The superiority of a horizontal over a triangular arrangement of conductors is viewed from a new angle, and the reasons for adopting a horizontal arrangement on wood poles for 260 miles of 110-kV line are given. Various problems in connection with the design of this line are set out, costs are given and the conclusion is drawn that it is much more economical than a line carried on lattice steel towers.

DOI:10.1049/ji-2.1943.0027

出版商:IEE    

年代:1943

数据来源: IET

摘要:

The paper discusses briefly the various known methods of measuring a.c. peak voltages in connection with h.v. testing, and mentions the errors and drawbacks associated with them.Results of a method of measurement, based on the principle of the diode peak voltmeter, are given whereby wave-shape and frequency errors are eliminated within wide limits. Comparisons are made with sphere-gap calibrations,1and also with a voltmeter of the “rectified condenser-current” type.2The method described, although primarily intended to apply directly to the h.v. connection, can be used in conjunction with a voltage transformer (or tertiary winding on the h.v. transformer).

DOI:10.1049/ji-2.1943.0030

出版商:IEE    

年代:1943

数据来源: IET

摘要:

The practical advantages of graphical methods for determining current-carrying capacities of cables are indicated, and charts are described by which the ratings of 3-core and single-core cables transmitting balanced 3-phase loads can be rapidly obtained. The charts are applicable to cables laid direct in the ground or in air, and take into account, where necessary, the mutual heating effect of feeders laid in the same trench.In order to exhibit the degree of accuracy obtainable, calculated and graphically determined values of rating are compared For a range of typical cases.

DOI:10.1049/ji-2.1943.0031

出版商:IEE    

年代:1943

数据来源: IET