摘要:

After a summary of the advantages of the high-rupturing-capacity cartridge fuse, the breaking-capacity requirements for fuses for use in low- and medium-voltage circuits, as set forth in British Standard No. 88—1939, are enumerated. The short-circuit operation of cartridge fuses is discussed, at first in a general way and then in the light of detailed investigations of the phenomena during the melting and arcing periods. Conclusions are drawn, both analytically and from test results, as to the effect of circuit conditions on the duty imposed, and these are compared with the requirements of B.S. No. 88.Following a Section dealing with the choice of materials, the various types of fuse for low- and medium-voltage circuits and for high-voltage circuits are considered. The paper concludes with notes on the application of these fuses.

DOI:10.1049/ji-2.1941.0002

出版商:IEE    

年代:1941

数据来源: IET

摘要:

A method is described whereby a record of the restriking-voltage transient of a system may be obtained at a circuit-breaker location without interruption of supply up to the test point, and without producing surges in the system of more than a few hundred volts. The oscillographic equipment and other apparatus which has been developed for this purpose is described, and test results which have been obtained at substations of an electricity supply undertaking are given and discussed.

DOI:10.1049/ji-2.1941.0007

出版商:IEE    

年代:1941

数据来源: IET

摘要:

This report deals with an investigation of eddy-current losses in multi-core circular-conductor and shaped-conductor paper-insulated wire-armoured cables, and the development of formulae by means of which the losses can be computed. The experimental work covers tests with balanced three-phase currents at frequencies from 25 to 300 cycles per second.The eddy-current losses are divided into four parts, namely, skin effect, proximity effect, lead-sheath effect, and armouring effect. The ratio of a.c. to d.c. resistance of the conductors, calculated by the appropriate formula, is, with one exception, within 5% of the measured value under all the conditions covered by the investigation, the average difference between calculation and measurement being only 1%.

DOI:10.1049/ji-2.1941.0008

出版商:IEE    

年代:1941

数据来源: IET

DOI:10.1049/ji-2.1941.0009

出版商:IEE    

年代:1941

数据来源: IET