Operator`s manual
GENERAL
INFORMATION
AND
CARE
OF
THE
GENERATOR
Use
of
Electric Motors
The
power required to start
an
electric motor is considerably more
tban
is required to keep
it
running
after
it
is started. Some motors require much more current to start
tban
otbers. Split-phase (AC) motors
require more current to start, under certain circumstances,
tban
other types. They are commonly used
on
easy-starting loads, such
as
washing machines,
or
where loads are applied after
tbe
motor is started, such
as
small power tools. Because they require 5 to 7 times
as
much current to start
as
to run, tbeir use should
be
avoided, whenever possible,
if
tbe
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 witb 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,
tbe
current required to start
lI5-Volt
motors connected to medium starting loads will be
approximately
as
follows:
MOTOR
SIZE
(HP)
lI6
1/4
1/3
lI2
3/4
AMPS
FOR
RUNNING
(Amperes)
3.2
4.6
5.2
7.2
10.2
13
AMPS
FOR
STARTING
(Amperes)
6.4 to
22.4'
9.2
to
32.2'
10.4 to
72.8'
14.4 to 29.2
20.4 to 40.8
26 to 52
'NOTE:
In
tbe
above table
the
maximum"
Amps for Starting" is more for some small motors
tban
for larger ones.
The
reason for this is that the hardest starting types (split-phase) are no
made
in
larger sizes.
Because tbe heavy surge
of
current needed for starting motors is required for only
an
instant,
tbe
generator
will not
be
damaged
if
it
can
bring
tbe
motor up to speed
in
a few seconds.
If
difficulty is experienced
in
starting motors,
tum
off
all otber electrical loads and,
if
possible, reduce tbe load
on
the
electric motor.
Required Operating
Speed
A1tbough individual units
may
vary slightly,
the
normal voltage
and
frequency
of
typical 60-(50-)Hertz
engine-driven generators described in
tbis
manual are approximately
as
follows:
run
first
witb
no
load
applied,
tben
at
half
tbe generator's capacity,
and
finally loaded to its full capacity
as
indicated
on
tbe
generator's
data
plate.
See tbe rpmlHertzlfrequency chart
on
tbe
next page.
57
WESTERBEKE
GENERATORS