Piper SENECA III User Manual

SECTION 7
PIPER
AIRCRAFT CORPORATION
DESCRIPTION
&
OPERATION
PA-34-220T,
SENECA III
7.17
ELECTRICAL
SYSTEM
The
electrical
system
of the
Seneca Ill
is
capable
of
supplying
sufficient
current
for
complete
night
IFR
equipment.
Electrical
power
is
supplied
by
two
65
ampere
alternators
(Figure 7-13),
one
mounted
on
each
engine.
A
35
ampere-hour,
12
volt
battery
provides
current
for
starting,
for
use
of elec-
trical
equipment
when
the
engines
are
not
running,
and
for
a source
of stored
electrical
power
to
back
up
the alternator
output.
The battery,
which
is
located
in
the
nose
section and
is
accessible
through the baggage
compart-
ment,
is
normally
kept
charged by
the alternators.
If it
becomes
necessary
to
charge
the battery,
it
should
be
removed
from
the
airplane.
Two
solid
state
voltage
regulators
maintain effective
load
sharing while
regulating
electrical
system
bus
voltage
to
14 volts.
An
overvoltage
relay
in
each alternator
circuit
prevents
damage
toelectricaland avionics equipment
by
taking
an
alternator
off the
line if its
output
exceeds
17
volts,
if
this
should
occur,
the
alternator
light
on
the
annunciator
panel
will
illuminate.
Voltage
regulators
and
overvoltage
relays
are
located
forward
of
the
bottom
of
the
bulkhead
separating
the
cabin
section
from
the
nose
section.
The
electrical
system
and
equipment
are
protected by
circuit
breakers
located
on a
circuit
breaker
panel
on
the
lower
right side of
the
instrument
paneL
The
circuit
breaker
panel is
provided
with enough
blank
spaces
to
accommodate
additional
circuit
breakers
if
extra
electrical
equipment
is
installed. In
the
event
of equipment
malfunctions
or a
sudden
surge
of
current,
a
circuit
breaker
can
trip
automatically.
The
pilot
can
reset
the
breaker
by
pressing
it
in
(preferably
after
a
few
minutes cooling period).
The
circuit
breakers
can
be
pulled
out
manually.
Most
of
the
electrical switches,
including
the
battery
switch
and
switches
for
magnetos,
fuel
pumps,
starters,
alternators,
lights
and
pitat
heat.
are
conveniently
located
on
the
switch
panel
(Figure
7-15)
to
the
left of
the
pilot's
control
wheel.
An
optional
starting installation
known
as
Piper
External
Power(PEP)
is
accessible
through
a
receptacle
located
on
the
lower
left
side
of
the
nose
section.
An
external
battery
can
be
connected
to
the
socket.
thus allowing
the
operator
to
crank the
engine
without
having
to
gain
access
to
the
airplane's
battery,
REPORT:
VB-1110
ISSUED: JANUARY 8, 1981
7-18
REVISED: AUGUST
9,
1982

Piper SENECA III Specifications

General

Manufacturer	Piper Aircraft
Model	Seneca III
Engine Type	Piston
Engine Model	Continental TSIO-360-KB
Seating Capacity	6
Cruise Speed	188 knots (216 mph, 348 km/h)
Length	28 ft 7 in (8.71 m)
Max Takeoff Weight	4, 750 lb (2, 155 kg)
Horsepower	220 hp each
Service Ceiling	25, 000 ft (7, 620 m)
Height	9 ft 11 in (3.02 m)
Propellers	2-bladed constant speed