Improvements in or relating to extra high tension switch gear for use with small currents at high voltages in plant for the electrical precipitation of dust in gases

摘要

565,885. High-tension switches. WHESSOE FOUNDRY & ENGINEERING CO., Ltd., and FRANCOMBE, K. W. May 11, 1943, No. 7468. [Class 38 (v)] Switchgear suitable for gasprecipitation plant, comprises a rotatable insulating rod or rods 8, each carrying a knifeblade'9 which can be.rotated to engage either contacts 71, 711 connected to sources of different voltage, or to engage a terminal 7 and so earth the plant connected to the blade 9. An incoming cable 12 is connected to contacts 711 directly and to contacts 71 through a pair of series-connected voltage-reducing resistances 15. An earthing switch 16 operable by handle 17 is provided for the cable 12. The circuits to outgoing cables 13 include ammeters 22 mounted on legs 21 on upper cross-members 3 which are spaced from lower crossmembers by members 5, 6, the whole being supported by angle-irons 4 from the lid 2 of the oil tank 1. Apertures 23 in the lid permit viewing of the meters 22 which are above the oil-level. The shafts 8 are operated by hand wheels or, as shown, by key-operated locks 11, the keys being removable only when the switch is earthed, and being also used for the L.T. isolator and only removable therefrom when open.