Raytheon Beech Baron E55 - Page 622

Raytheon
Aircraft
Company
BARON
55
AND
58
SHOP MANUAL
OVERVOLTAGE
TRIP
(BENCH
CHECK)
Overvoltage
protection
is
incorporated
in the
voltage regulator
which
locks
out
the
output
of
the
regulator
in the
event
an
overvoltage
occurs.
The
voltage
regulators
are
shipped
from
the manufacturer
with the
overvoltage trip
point
preset.
To
convert
from
the
voltage
adjustment
test to
overvoltage
test
the
following
revisions
to
the
test
setup
must
be
made:
1.
Disconnect
the
dummy
load.
1
2.
Add
a
small 28
volt
relay
for
overvoltage
indication
(Ref. Figure
5).
3.
Add
a
press-to-test
switch
in the
input
connection.
Overvoltage
trip
adjustment
is
accomplished
as
follows:
I
a.
Set
up
the
test
items
as
indicated
(Ref. Figure
4).
b.
Turnthe
powersupplyON.
c.
Bring
the
output
of
the
power
supply
up
until 28.5
volts is
indicated
on
the
precision
voltmeter.
d.
Wait
5
to
13 minutes
to
allow
the
alternator
control unit
to
reach
operating
temperature.
e.
After the alternator
control
unit
has warmed
up,
increase the
output
of the
power
supply
to
31.8
volts.
f.
Depress
the
press-to-test
switch
and
hold
for
5
seconds.
The
contactor
indicator
should be activated for
the
full
time
the
press-to-test
switch is
depressed.
g.
Set
the
regulated
voltage
to
32.2
vdc.
Depress
the
press-to-test
switch and hold
for
5
seconds;
the
contactor
indicator
should
activate.
After
a
fractional
second
delay,
the
overvoltage
indicator
should
activate and
simultaneously
the
contactor
indicator
should deactivate.
NOTE:
The
overvoltage
trip
is
preset
at
the
factory
and should
not
be
adjusted
under
field
conditions.
If
the unit
under
test
does
not
operate
within the
parameters
of this
test,
the
unit
should be
tested
in
a
fully
equipped
test
facility
or
replaced.
h.
Turn
the
power
supply
to
off and
remove
alternator
from
the
test
setup.
Dec
31/03Page
24
SECTION
13
E21