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
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 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 con-
nected 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. 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, 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 ampmeter is not installed to monitor voltage and
load, check it with a portable meter and amprobe.
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 corifigured to pro-
vide one
/20
volt
AC
hot leg
for
the vessel's distribution
panel. This will ensure good motor starting response from the
generator.
GENERATOR
FREQUENCY
ADJUSTMENT
Frequency is a direct result
of
engine/generator speed,
as
indicated by the following:
• When the generator is run at 1800 rpm, the AC voltage
output frequency is
60 Hertz.
• When the generator is run at 1500 rpm, the AC voltage
output frequency is
50 Hertz.
Therefore, to change the generator's frequency, the genera-
tor's drive engine's speed must be changed along with a
reconfiguring
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 exces-
sive 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 single 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 cor-
ners
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!
Engines & Generators
36