Installation manual
GENERATOR
INFORMATION
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 them than
others. Split-phase (AC) motors require more current to start,
under similar circumstances, than other types. They are com-
monly used on easy-starting loads, such
as
washing
machines, or where loads are applied after the motor is
started, such as small powertools. 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 repulsion-
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 con-
nected 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 U5-Volt motors connected
to
medium starting loads will
be
approximately
as
follows:
MOTOR
SIZE
AMPS
FOR
AMPS
FOR
(HP)
RUNNING
STARTING
(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
to
52
*NOTE:
In
the above table the maximum Amps
for
Starting is
more for some small motors than
for
larger ones.
TIw
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
Run the generator first with no load applied, then
at
half the
generator's capacity, and finally loaded to its full capacity as
indicted on the generators data plate. The output voltage
should be checked periodically to ensure proper operation
of
the generating plant and the appliances it supplies. To
monitor voltage and load, check it with a portable meter and
amp probe.
Generator
Maintenance
Maintaining reasonable cleanliness is important. Connections
of
terminal boards and rectifiers may become corroded, and
insulation surfaces may start conducting
if
salts, dust, engine
exhaust, carbon, etc. are allowed to build up. Clogged
ventilation openings may cause excessive heating and
reduced life
of
windings.
In addition to periodic cleaning, the generator should be
inspected for tightness
of
all connections, evidence
of
overheated terminals andloose or damaged wires.
Engines
& Generators
40