Piper ARCHER III Pilot Operating Handbook page 236

SECTION
7
DESCRIPTION
&
OPERATION PA-28-181
ARCHER
III
7.21 ELECTRICAL
SYSTEM (continued)
aemrnq
3}-minutes
of power
from
the emergency battery
is only available
if
its voltage is
greater than 23.3
volts
prior
to flight.
Ensure
that
a
minimum of
23.3
volts is available
prior
to
flight.
The
emergency
battery is isolated
from
the
emergency bus
equipment via
a
relay, which is controlled
from
the
cockpit by
the
EMERG
BATT
switch. The
emergency battery
is
also isolated
from the electrical power generating system
via
a
diode
in
the
circuit. This
diode
will
allow
the
generating
system to charge
the emergency battery
during normal
operations
but prevents discharge
of
the
emergency battery when operating
with
the
alternator off. The emergency battery
is mounted on
a
shelf
in
the
aft
fuselage
area
just
forward
of
the
primary
battery.
Switches
All
powerplant,
electrical power, exterior lights, and avionics
master
switches are grouped
in
an overhead
switch panel
as
shown
in
Figure 7-10.
The
circuit
breaker panel
is
located
on
the
lower
right
side
of
the instrument panel
(Figure 7-9).Each
breaker is
clearly
marked
to
show
which
circuit it
protects,
Standard
electrical
accessories
include the
starter,
electrical
fuel pump,
the
stall
warning
lift
detector,
navigational lights,
anti-collision lights, landing lights,
I
and cabin dome
lights.
The
autopilot (optional),
pitot
heat,
ventilation
fan,
and
'
air-conditioning (optional)
switches
are
located
in
the middle
of
the instrument
panel,
just
below
the
G1000 audio panel.
Two lights
mounted
in
the
overhead
panel provide cabin
flood
lighting
for
night flying. The
lights
are
controlled
by
rheostat switches located
in
the
overhead panel,
A
map
light
window
in
each lens
is
actuated
by
an
adjacent
switch.
A wing tip
landing
light
system consists
of two lights (one
in
each
wing
tip)
and
is
operated
by
a
rocker type switch
mounted
in
the overhead switch
panel.
Light
intensity
for
the
back-lit
switches, instrument panel lights,
and the
avionics are
controlled
by
three
rotary control located on the instrument panel
just
below
the
electrical accessory switches.
MSUS
Anti-collision (strobe) lights
should
not
be
operating when
flying through
cloud,
fog or
haze, since
the
reflected
light
can
produce
spatial
disorientation. Strobe
lights
should
not
be
used
in
close
proximity
to the
ground
such
as
during taxi, takeoff
or
landing.
REPORT: YB-2749
7-50
ISSUED: December
22,
2Ol7
REVISED: August
29,
2OI9