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Figure 39. Back of switchboard arranged for two generators and three-wire system.
The back of the switchboard.
leads from the generators come up through the floor and are made of large flexible cables. As will be noticed, all the bars are supported entirely by the connections
Showing cables and rheostats. with the switches and other devices, just as in Fig. 27. A side elevation in section is shown in Fig. 40.
Fig. 41 is a photographic view of the back of the switchboard, the front of which is shown in Fig. 42. The five large disks, seen in the back view, are the field rheostats, and by looking at Fig. 42 it will be seen that they correspond in position with the five small hand wheels located in the center panel of the board. This
As seen from the front.
board, therefore, is arranged for five generators, and the connections are upon the two-wire system, which is shown
by the fact that the switches in the two side panels are of the two pole type.
From Fig. 41 it will be seen that in this case, the conductors are in part bars, and in part cables, and they are not secured entirely by the bolts that form the connec
A very complete board. tions with the switches, circuit breakers, etc., but are also held directly against the marble slabs. This composite construction is commonly followed when the capacity of the plant is small, but when it is sufficiently large, wires and cables cannot be used advantageously, although in