Beechcraft 20138 - Page 35

The
following
brief
outline of tests is
intended
as
a
guide for
setting
up suitable
test facilities.
:
In addition to
the
equipment
called
for
in
Section
4-1,
the
test
facility
should
have
a suitable
motor-alternator
system,
with
battery or dummy
load
to
simulate
the
aircraft installation
and
a bench
power
supply
capable of
being
varied
from
approximately
25
to
35
volts
D.C.
at less than one amp.
O :
This procedure
should
follow
Section
4-1,
steps
(a)
through
(d)
(Output
Voltage).
O
This procedure
can
follow Section 4-1,
steps
(a)
through
(k),
(Overvoltage) or the alternative
procedure
listed
below.
a)
Connect
the
regulator
to the test set
up to
simulate installed
conditions
exce2t
for
the following,
b) Disconnect voltage regulator pin
A from pins
H,
J,
&
F
and
bring
pin A
out to the
external D.C. power supply.
Leave
pins
H,
J, and
F
connected to the
buss,
c)
Connect
pin
A
to the positive
terminal
of
the external
D.C.
power
supply and
connect the
common
(pin
C)
to
the
negative
terminal
of the
power
supply.
The
overvoltage
protection
circuit
can
now sense the external power
supply
voltage,
d)
Adjust
the
external power
supply
to
approximately 28,0
volts
D.C.
e)
With
the
alternator
running,
monitor
the buss voltage.
It
should
read
28.5
volts
±0.25
volt (or to some other specific
voltage
as previously
set).
The
overvoltage
warning
light
should be
éxtinguished.
4-5