. Transactions of the Institution of Mining Engineers . rder to ensure thaifc a good earth contact is made between the 1920-1921 ] EAMSAY i SUBMERSIBLE ELECTRIC MOTORS. 177 two half casings, three flat copper strips hxed in equidistant positionsaround the plug half spring into suitable seatings on the other halfcasing. The joint between the two halves is made on a flat machinedsurface with a packing-washer, which is pulled tight by a stiflf locking-nut. Covers are provided for protecting the contacts when not in stuffing-box is fitted at the neck of each half-coupling, which wservesthe d
. Transactions of the Institution of Mining Engineers . rder to ensure thaifc a good earth contact is made between the 1920-1921 ] EAMSAY i SUBMERSIBLE ELECTRIC MOTORS. 177 two half casings, three flat copper strips hxed in equidistant positionsaround the plug half spring into suitable seatings on the other halfcasing. The joint between the two halves is made on a flat machinedsurface with a packing-washer, which is pulled tight by a stiflf locking-nut. Covers are provided for protecting the contacts when not in stuffing-box is fitted at the neck of each half-coupling, which wservesthe double purpose of making the interior watertight and of relievingthe cable-connexions of mechanical stress. In cases where the cable armouring is used for earthimg purposes, amodification is necessary at the neck of the coupling, and such anarrangement will be described later in connexion with a large pumpingset for sinking work The insulating block is provided with a locating feather, whichis in a fixed position with reference to the exterior Fig. 13.—Portable G-Inch Double-inlet Submersible Motor-pump inDip Workings. Fig. 13 is a drawing of a 6-inch double-inlet pump coupled to a 50-horsepower motor installed in a mine in Gloucestershire for use in dip workings. The set, as will be seen, is mounted on a trolley. Fig. 1-1gives the curves of the motor-pump taken on test. De-watering Shafts.—From the description given, it \vill be agreedthat the submersible mctor-pump is eminently suitable for pumpingout shafts and pits. The following additional advantages may bebriefly stated : — (1) The whole unit may be submerged, thus eliminating the necessityfor suction-pipe and foot-valve, with the attendant losses and troubleson the suction. (2) Great saving in time and labour, as delivery-pipes and feeding-cable can be fitted in one operation, providing for a lengthy run beforeit is necessary to shut down again for adding additional lengths. As an example of what may be ac
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Keywords: ., bo, bookcentury1800, bookdecade1890, booksubjectmineralindustries
