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GENERAL INFORMATION AND CARE OF THE GENERATOR
Use of Electric Motors
The power required to start an electric motor is considerably more than is required to keep it running after
it is started. Some motors require much more current to start than others. Split-phase (AC) motors require
more current to start, under similar circumstances, than other types. They are commonly used on easy-
starting loads, such as washing machines, or where loads are applied after the motor is started, such as
small power tools. Because they require 5 to 7 times as much current to start as to run, their use should be
avoided, whenever possible, if the electric motor is to be driven by a small generator. Capacitor and repul-
sion-induction motors require from 2 to 4 times as much current to start as to run. The current required to
start any motor varies with the load connected to it. An electric motor connected to an air compressor, for
example, will require more current than a motor to which no load is connected.
In general, the current required to start 115-Volt motors connected to medium starting loads will be ap-
proXimately as follows:
MOTOR
AMPS FOR
AMPS FOR
SIZE
RUNNING
STARTING
(HP)
(Amperes)
(Amperes)
1/6
3.2
6.4 to 22.4*
1/4
4.6
9.2 to 32.2*
1/3
5.2
10.4 to 72.8*
1/2
7.2
14.4 to 29.2
3/4
10.2
20.4 to 40.8
1
13
26 t052
* Note that in the above table the maximum "Amps for Starting" is more for some small motors
than for larger ones. The reason for this is that the hardest starting types (split-phase) are not
made in larger sizes.
Because the heavy surge of current needed for starting motors is required for only an instant, the generator
will not be damaged if it can bring the motor up to speed in a few seconds. If difficulty is experienced in
starting motors, turn off all other electrical loads and, if possible, reduce the load on the electric motor.
Required Operating Speed
Although individual units may vary slightly, the normal voltage and frequency of typical 60-(50-) Hertz engine-
driven generators described in this manual are approximately as follows: run first with no load applied, then
at half the generator's capacity, and finally loaded to its full capacity as indicated on the generator's data
plate.
See the rpm/Hertz/frequency chart on the next page.
39
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