Ans. Apparatus should be installed as a prevention against accidents, such as fire, and protection of attendants from danger.
In every electrical station there should be a pump, pipes and hose; the pump may be either directly connected to a small electric motor or belted to a countershaft, while the pipes and hose should be so placed that no water can accidentally reach the generators and electrical circuits. A number of fire bucket filled with water should be placed on brackets around the station, and with these there should be an equal number of bucket containing dry sand, the water being used for extinguishing fire occurring at a distance from the machines and conductors, and the sand for extinguishing fire in current carrying circuits where water would cause more harm than benefit. To prevent the sand being blown about the station, each sand bucket, when not in use, should be provided with a cover.
Neat cans and boxes should be mounted in convenient places for greasy rags, waste, nuts, screws, etc., which are used continually and which therefore cannot be kept in the storeroom.
While it is important to guard against fire in the station, it is equally necessary to provide for personal safety. All passages and dark pits should therefore be thoroughly lighted both day and night, and obstacles of any nature that are not absolutely necessary in the operation of the station, should be removed. Moving belts, and especially those passing through the floor, should be enclosed in iron railings. If high voltages be generated, it is well to place a railing about the switchboard to prevent accidental contact with current carrying circuits, and in such cases it is also advisable to construct an insulated platform on the floor in front of the switchboard.
Fig. 2,819.—Method of joining adjacent switchboard panels.
Switchboards.—The plan of switchboard wiring for alternating current work depends upon the system in use and this latter may be either of the single phase, two phase, three phase, or monocyclic types. The general principles in all these cases, however, are practically identical.
[Fig. 2,820] shows the switchboard wiring for a single phase alternator. As an aid in reading the diagram, the conductors carrying alternating current are represented by solid lines, and those carrying direct current, by dotted lines.