rting a
charge at 10 amperes, and the other for charging the batteries, that
have begun to gas, at a reduced rate. Fig. 46 shows a 2 K. W.
four-circuit, 32 battery motor-generator set. Each circuit is provided
with a separate rheostat and ammeter. The two terminals near the top
of each rheostat are connected to one charging circuit. The two
terminals near the lower end of each rheostat are connected to the
generator.

The 2 kilowatt set is suitable for a city garage, or a battery service
station in a medium sized town. A beginner should not purchase this
large set, unless the set can be operated at at least one-fourth
capacity continuously. As a service station grows, a 5 kilowatt set
may be needed. The 1, 2 and 5 kilowatt sets should not be used on
anything but city power lines. Single phase, or lighting lines are not
satisfactory for handling these sets.

A few suggestions on Motor-Generator Sets

1. Installation. Set the motor-generator on as firm a foundation as
possible. A good plan is to bolt it to a heavy bench, in which
position it is easily inspected and adjusted, and is also less likely
to be hit by acid spray, water, etc.

Set the motor-generator at some distance from the batteries so that
acid spray and fumes will not reach it. Sulphuric acid will attack any
metal and if you are not careful, your motor-generator may be damaged
seriously. The best plan is to have the motor generator set outside of
the charging room, so as to have a wall or partition between the
motor-generator and the batteries. The charging panels may be placed
as near the batteries as necessary for convenience, but should not be
mounted above the batteries. Figure 47 shows a convenient layout of
motor-generator, charging panels, and charging benches. Note that the
junipers used in connecting the batteries together are run through the
upper holes of the wire porcelain insulating cleats, the lower hole of
each insulator supporting the wire from the charging panel which runs
to the end of the bench.

[Fig. 47]

Fig. 47. Convenient Arrangement of Motor-Generator, Charging Panels,
and Charging Benches

Instructions for the wiring connections to the power lines generally
come with each outfit, and they should be followed carefully. Fuses in
both the motor and generator circuits are especially important, as
they protect the machines from damage due to overloads, grounds, or
short-circuits. The generator must be driven in the