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GENERATOR INFORMATION
USE OF ELECTRIC MOTORS
The JX>Wer 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
'
commonly used on easy-starting loads, such as washing
machines, or where loads are applied after the motor is
s~,
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 dri-
ven 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 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
approximately as follows:
MOTOR SIZE
AMPS FOR
AMPS FOR
(HP)
RUNNING
(~TARTING
(AMPERES)
AMPERES)
1/6
3.2
6.4to 22.4*
1/4
4.6
9.2to 32.2*
113
5.2
10.4to72.8*
1/2
7.2
14.4 to 29.2*
314
10.2
20.4 to 40.8*
1
13
26to 52
*NOTE: 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 staning types (split-phase) are not
nu:ule in larger sizes.
Because the heavy surge of current needed for starting
motors is required for only an instant, tl}e 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, tum
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 generator's data plate. The output voltage
should be checked periodically to ensure proper operation of
the generating plant and the appliances it supplies. If an AC
voltmeter or amp meter is not installed to monitor voltage
and load, check it with a portable meter and amp probe.
NOTE:
When the vessel in which the generator is installed
contains AC equipment of 120 volts only, it is recommended
that the generator's AC terminal block be configured to
provide one 120 volt AC hot leg for the vessel's distribution
panel. This will ensure good motor staning response from the
generator.
GENERATOR FREQUENCY ADJUSTMENT
~l"e9uency
is a direct result of engine/generator speed, as
mdicated by the following:
• When the generator is run at 1800 RPM, the AC voltage
output frequency is 60 Hertz.
Therefore, to change the generator's frequency, the
g~nerat'Or's
drive
~ngine's
speed must be changed along
wtth a reconfigurmg of the AC output connections at the
generator.
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.
• For unusually severe conditions, thin rust-inhibiting
petroleum-base coatings should be sprayed or brushed
over all surfaces to reduce rusting and corrosion.
• In addition to periodic cleaning, the generator should be
inspected for tightness of all connections, evidence of
overheated terminals and loose or damaged wires.
• The drive discs on s,ingle bearing generators should be
checked periodically if possible for tightness of screws
· and for any evidence of incipient cracking failure. Discs
should not be allowed to become rusty because rust may
accelerate cracking. The bolts which fasten the drive disc
to the generator shaft must be hardened steel SAE
grade
8, identified by 6 radial marks, one at each of the 6
comers of the head.
• The rear armature bearing is lubricated and sealed; no
maintenance is required. However, if the bearing becomes
noisy or rough-sounding, have it replaced.
• Examine bearing at periodic intervals. No side movement
of shaft should be detected when force is applied. If side
motion is detectable, inspect the bearing and shaft for
wear. Repair must be made quickly or major components
will rub and cause major damage to generator.
Carbon Monoxide Detector----------.
WESTERBEKE recommends mounting a carbon
monoxide detector in the vessels living quarters. Carbon
monoxide, even
in
small amounts,
is
deadly.
The presence of carbon monoxide indicates an exhaust
leak from the engine or generator or from the exhaust
elbow/exhaust hose, or that fumes from a nearby vessel
are entering your boat
If carbon monoxide is present, ventilate the area with
clean air and correct the problem immediately!
Engine$
c1
Genera.tOr$
29
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