proper direction
or the generator will not build up. The rotation of a three-phase
motor may be reversed by reversing, and Charging Benches any two of
the cables. To reverse a two-phase motor, reverse the cables of either
phase. Before putting a motor-generator set into operation, be sure to
check all connections to make sure that everything checks with the
instructions furnished by the manufacturer.

Operating the Charging Circuits

A generator operates most efficiently when delivering its rated
output. Therefore, keep the generator as fully loaded as possible at
all times. When you do not have enough batteries to run the generator
at full load, run each charging circuit at full load, and use as few
circuits as possible. This will reduce your power bill, since there is
a loss of power in the rheostat of each charging circuit, this loss
being the greatest when only one battery is on the circuit, and a
minimum when the circuit is fully loaded.

With several charging circuits, it is also possible to put batteries
which are in the same condition on one circuit and adjust the charging
rate to the most suitable value. Thus, badly sulphated batteries,
which must be charged at a low rate, may be put on the same circuit,
while batteries which have had only a normal discharge may be put oil
another circuit and charged at a higher rate. As each battery becomes
almost fully charged, it may be removed from the circuit and put on
another circuit and the charge completed at the finishing rate. This
is a good practice, since some batteries will begin to gas sooner than
others, and if the charging rate is not reduced, the batteries which
have begun to gas will have active material blown out by the continued
gassing. A careful study of such points will lead to a considerable
saving in power costs.

Care of Motor-Generator Set

A. Machine will not build up or generate. This may be due to:

1. Machine rotating in wrong direction.
2. Brushes not making good contact. Clean commutator with fine
sandpaper.
3. Wrong connections of field rheostat-check connections with
diagram.
4. Open circuit in field rheostat. See if machine will build up
with field rheostat cut out.

B. Excessive heating of the commutator. This may be due to:

1. Overload--Check your load and compare it with nameplate
reading. Add the total amperes on all the panels and see that it
does not exceed the ampere re