Entire load on one generator.

ranged so as to be fed from the street mains, and the connections are such that at any time a part of the system can be operated from the street mains and the balance from the generators. Any one of the generators can be connected with the entire system of circuits, or the power and light portions may be run separately, two generators furnishing current for one part, and the other generator supplying the remainder. The way in which these results are accomplished can be readily understood from the following description:

The three generators are connected with the system in the same order; hence, the description of the connections of one will answer for the other two. Looking at the generator GI it will be seen that the lines a and b run to the lower terminals of the circuit breaker CBI. Line c, which is the equalizing connection, runs to the center terminal of the SI switch, directly above the circuit breaker. The center terminal of the circuit breaker is connected with the lower center terminal of the S1 switch, and the top circuit breaker terminal connects with the rectangle marked W1, which is a wattmeter. From the other terminal of this wattmeter a connection runs to the top center terminal of the SI switch, thus connecting the three center terminals of this switch with the generator terminals.

When the SI switch is thrown to the right side, as shown in the diagram, bus g is connected with the center terminal of the circuit breaker, and this, through the rightside lever, is connected with the generator lead b. In the same way bus f is connected through the wattmeter and the circuit breaker with generator lead a, and bus i is connected directly with lead c. From this it will be

Tracing the connections.

seen that bus i is an equalizing bus. When the SI switch is thrown to the left generator lead a is connected with bus d, and lead b with bus c, while the equalizer lead c is connected with bus h. Thus when the switch is thrown in opposite directions it connects the generator terminals with two different sets of busses, and in these two sets h and i are equalizing busses, while d corresponds to f, and e to g.

If we follow the busses e and d to the left we will find that they run to a rectangle F, which is a double pole safety fuse, and from here to a switch S. From this last switch lines run up that connect with fourteen smaller switches marked S L. Each one of these switches feeds into a lighting circuit, only two of which, marked n n, are shown, to avoid confusion. Adjoining the switch S, are two other switches S. and S,, and these are connected through the safety fuses F' F' with the street mains. Switch S, is connected with one row of the S L switches, and switch S, with the other row. The S L switches are of the double-throw type, and when turned in one direction connect the lighting circuits n n with the street mains, and when turned in the other direction connect them with the busses e and d. If the switches S, and S, are closed, any one of the S L switches can be turned so as to take current from the generators or from the street.

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If we follow the e and d busses to the right we will find that they lead to two of the switches marked Sm and also to the top side terminals, of the switch S. Following the g and f busses we find that they run to the lower corner terminals of the S, switch, and from here to the safety fuse F" and the switch S. From the upper rightside terminal of the S, switch a connection runs to the

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