43
ADJUSTMENTS
GENERAL. - Generating plant
satisfactory
performance
is
dependent
upon
correct
adjustments.
Adjustmehtscan
not fully
com-
pensatefoI'
troubles
such
as
low
engine power due
to
engine condition.
GOVERNOR
AND BOOSTER ADJUSTMENT. - The
governor
and
booster
controls.
the
speed of
the
engine. A speed fl-djustment includes adjusting both d.evices.
Refer
to
the
Governor and Booster
illustrations.
Carefully
study the
related
subj
ects
in the following
paragraphs
and .
check each point in
the
order
given
before
attempting
adjustments
on the
governor:
. '
1..
GENERAL. - Before making final governor
adjustments,
run
the
plant
about
15
minutes under
light
load
to
reach
nor:"
mal
operating
temperatirie.
(If the governor is completely out
of
adjust-
ment, make a
preliminary
adjustment
at
no load
to
first
attain
a
safe
voltage
operating
range.
) .
On
a c
generating
plants,engine
speed
determines
the
output voltage
and
.current
frequency
of
the
generatqr
..
By
increasing
the
engine speed,
generator
voltage and frequency
is
in~reased,
and by
decreasing
the
en-
gine speed,
generator
voltage and frequency
is
decreased.
An
accurate
voltmeter
or
frequency
meter
(prefetably
both) should
be
connected
to
the
generator
output
in
order
to
correctly
adjust
the
governor
of
the a c
plant. A
small
speed
drop
not noticable without .instruments will
result
in an
objectionablevoltagedrop.
The engine speed can be checked with
a
tachometer.
The governor
arm
is
fastened
to
a snaft which extends
from
the
gear
cover,
and
is
connected
by
a
ball
joint and link
to
the.carburetor
throttle'
arm
..
Flyballs
behind
the
cup
on
the;
camshaft
gear,
actuate
the
gover-
nor
arm.
If
the
carburetor
has
been removed,
or
the
governor
disas-
sembled,
it
maybe
necessary
to
readjust
the
governor.
The'speed
booster
is
a
separateauxUiary
device which supplements
the
function
·of
the
governor ; The speed
booster
is
adjusted
to
increase
gov-
ernoraction
as
the load
on
the
generator
is
increased.
The
booster
serves
to
maintain
or
increase
the speed
at
the
higher
loads.
This
re-
sults
iIi
more
nearly
constant output voltage. '
The
booster
is
mounted on
the
intake manifold and
is
operated
by engine
'1':'"
!
vacuum
through
a
small
passage
in
the
manifold. When
the
plant
isop-
. i
.•.
erating
at
about
half load
or
less,
theenginevacuumissufficiel1t
to ......
',
cause
the' diaphragm
to
overcome
the
tensiOll
of
the
internal
booster'
1
spring.
Under
these
coriditions,
there
is
no tension
on
the
booster
e}"1er-
....
~
..
i'."!
nal
spring
and
the'boosterdoes
not affect·
the
governor
operation.
.~
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