attendant making accidental contact with any high-tension connections. The insulating panels are supported on an iron framework A, which may be bolted directly to a wall. By this arrangement the whole of the gear may be assembled in the manufacturer's works, and in consequence the erection in the user's works is greatly simplified. The high-tension fuses B and main ammeters C are mounted on removable panels D, D1, and these panels, when closed, form an efficient guard for the connections behind them. The act of removing these panels disconnects the fuses, etc., from the contacts behind, and affords ready access to these contacts and connections. The circuit in the particular construction shown in fig. 134 is broken by a water break switch mounted at the top of the board. This switch is controlled by a lever, the handle of which projects from the lower face of the board. In a later design oil break switches are substituted for the water break switches shown. Figs. 135 and 136 represent a board made for Shanghai by Messrs Cowan, to the specification of Messrs Preece & Cardew. The apparatus controlling each generator, or feeder, is separated from adjacent sections by slate partitions. It will be seen that, although an iron framework is used for supporting the panels, this is so entirely covered by slate that it is impossible for an arc to be established between it and the high-tension connections. Hastings Wall Type Switchgear. The switchgear at Hastings (fig. 137) was designed to permit the use of discriminating cutouts for controlling the generators. These cutouts, which also serve as main switches, are bolted to a channel iron framework fixed to a glazed brick wall, which forms the background of the switchboard. The conductors from the generators, etc., are run in iron pipes cleated to the face of the wall in such a manner that the purpose of each conductor can be seen at a glance. A sectional elevation of this arrangement is shown in fig. 138. FIG. 137.-Hastings wall type switch-gear. The connections are indicated by dotted lines. The conductor on the extreme right is the lead from the inner pole of the generator. This is taken directly into the current-direction-indicating transformer A. From this a wire is run to one of the terminals of the circuit-breaker B; the FIG. 138.-Section of Hastings wall type switchgear. other terminal of this circuit-breaker is connected to the ammeter contact C, the ammeter D, and two-way switch E. By means of this switch the generator may be connected to either of the 'bus bars F or G. Contacts are provided in the transformer A for the synchronising plug H, by means of which the generator may be plugged on to the synchroniser 'bus bar. -F E |