General Information And Care Of The Generator - Westerbeke 7.6 KW BTD 60Hz 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