Voltage Regulator Adjustment - Raytheon BEECH BARON 58P Maintenance Manual

BEECHCRAFT
BARON 588
MAINTENANCE MANUAL
CA UTION
e.
Using
a
portable precision voltmeter
(0-50
volt
range
1%
accuracy),
connect
the
POSITIVE lead
to
the
During all
tests
and adjustments
on
the voltage BUS terminal
of the left
voltage regulator and the
regulators,
make
certain that the
FIELD NEGATIVE lead
to
the GND terminal of the left voltage
circuits, including
any
meter
or
test
leads
on
regulator.
these circuits,
are
always protected
from f. Remove
the
snap
plug
from the left voltage
accidental
grounding
to
airplane
structure
and
regulator adjustment hole and
adjust the voltage
to
28.25
contact
with other circuits.
Even
a
momentary
.25 vdc.
Replace the
snap
plug.
Do
not
make
any
further
ground
contact may
permanently damage the
adjustments
on
the left
voltage regulator.
voltage
regulator.
g.
Shut down the left
engine according
to
the
ENGINE SHUT DOWN procedures
in the
applicable Pilot's
Operating
Manual. Ensure
that the
battery
master
switch is
a.
Remove
the wire marked
PAR from the
right in the off
position.
voltage regulator.
During voltage regulator adjustment,
h. Connect
a
portable voltmeter
(non-precision) such
several
operations of connecting
and disconnecting
the PAR
as
the
SIMPSON #260
or
equivalent
between the FIELD
circuitare
required by the following
steps.
For
terminals of the left and right voltage regulators.
Leave the
convenience,
a
switch
or a
dependable clip
connections
may
existing
wires in place.
Connect the
POSITIVE lead of the
be
attached
to
the wire
to
facilitate
adjustment procedures. voltmeter
to
the left voltage
regulator FIELD terminal and
the
NEGATIVE lead of the voltmeter
to
the right voltage
regulator
FIELD terminal. Use
a
0-30
or
0-50
volt range
initially.
NOTE
Opening the
PAR circuit
disables the
balancing
NOTE
circuits of both
voltage regulators, allowing
them
to
operate
independently
for adjustment An
electronic digital voltmeter
is
not
purposes.
If this
circuit touches
any
other
recommended for
the
paralleling adjustment.
circuit
or
the airplane
structure, erroneous
results will be
obtained.
i.
Restart the left engine according
to
the ENGINE
START procedures in
the
applicable
Pilot's Operating
b.
Start the left
engine according
to
the
ENGINE
Manual.
START procedures in
the
applicable Pilot's
Operating
j. Place the
LT and RT ALT switches in the
on
Manual. Do
not start
the
right engine. positions.
c.
Position the LT ALT switch in the
on
position.
Check
to
make
sure
the RT
ALT switch is in the
off
position.
NOTE
d.
Run the left engine
for 5
to
10 minutes
at
an
engine speed
of 1200
rpm
with
a
load
current
of 15
to
30 The right engine is
not
operating.
amperes
(30% load
reading
as
indicated
on
the
left
loadmeter, located in the
center
section of the instrument k.
Remove
the
snap
plug
from the
right voltage
panel).
This will allow the
voltage regulator
to
obtain regulator adjustment hole.
Slowly
rotate
the right voltage
operating
temperature.
Do
not
use
cruise
or
high
rpm.
regulator
adjustment
while observing the voltmeter
connected between
the FIELD terminals. If
a
reverse
(downscale) reading
is obtained with the
meter
polarity
as
specified, turning the
right voltage regulator adjustment
NOTE
counterclockwise will
bring
the
meter
up
scale.
Slowly
set
the
right
voltage regulator adjustment
to
a
point
where the
Adjustment and
paralleling should always
be voltmeter will read
a
low value. Any reading
from 0
to
8
made with
a
substantial load
on
the
airplane volts is acceptable.
A lower
meter
range such
as
0-10 volts
system. The voltage
regulators require
a
certain
may
be used for this adjustment.
amount
of voltage
at
the field terminals
(about
2 volts) in order for the
paralleling action
to
become active. It is
characteristic
of this system
NOTE
that with
very
high
rpm
and
very
low loads, the
paralleling action
ceases
and in the
extreme
A stable reading
should
not
be expected
while
case,
one
alternator may be
entirely
cut
off.
the PAR circuit
is open.
24-31-00
Page 202
Apr
1/75