Piper SENECA III - Page 198

SECTION 7
PIPER
AlRCRAFT
CORPORATION
DESCRIPTION &
OPERATION
PA-34-220T,
SENECA
Hl
SN
34-8333001
AND UP
A
single
ammeter
on
the
instrument
panel
indicates
both battery
charging
current
and alternator
output.
When
the
ammeter
needle
indicates
to
the
left
of
center,
the
battery
is
beíng discharged;
when
the
needle
indicates
to
the
right
of
center.
the
battery
is
being
charged.
During
single-engine
operation.
this
feature
can
be
used
to
determine
how
much
theelectricalload
should
be
reduced.
To
check the
output
of
each alternator
individually,
use
the
press-to-test
buttons
located
on
either
side of the
ammeter.
The
left
button,
when
depressed,
will
cause
the
ammeter
to
indicate
left
alternator
output.
and
the
right
button.
when
depressed. will
indicate
right alternator
output.
These
buttons
are
the
momentary
type,
and
indicate
alternator
output
only
while
depressed.
Approximately 2000
RPM
or more
is
required
to
obtain
fullalternator
output
of
65
amperes.
11
is
normal
to
have
zero
output
at
idle
RPM.
This
is
due
to
the
reduced
drive
ratio
from the
engine.
Ammeter
and
the
ALT
annunciator
lights
provide
a
means
of monitoring
the
electrical
system
operation.Should
the
ammeter
indicate
a
load much
higher
than
the
known
consumption of the
electrical
equipment
in
use. an
alternator
malfunction
should
be
suspected
and
the
respective alternator
switch
turned
off.
ln
this
event,
the
remaining
alternator
should show
a
normal
indication
on
the
ammeter
after
approximately
one
minute,
if
both
alternators
indicate
a
load
much
higher
than the
known
consumption
for
more
than
approximately
five
minutes,
an
electrical
defect
other
than the alternator
svstem
should
be
suspected
because
a
discharged
battery
will
reduce
the
alternator
load
as
it
approaches
the
charged
conditions.
A
zero
ammeter
reading
indicates
an
alternator
is
not
producing
current
and should
be
accompanied
by
illumi-
nation
of
the
ALT
annunciator light.
A
single
alternator
is
capable
of
supporting
a
continued flight in
case
of
alternator
or
engine
failure in
most
conditions: however,
with
deicing
equipment
and
other
high
loads,
care
must
be
exercised
to
prevent
the
loads
from
exceeding
the
65
ampere
rating
and subsequent
depletion
of
the
battery.
For
abnormal
and
or emergency
operations
and
procedures
refer
to
Section 3
-
Emergency Procedures.
CAUTION
Do
not
use
cigar
lighter
receptacles
as
power
sources
for
any
devices
other
than
the
cigar
lighters
supplied with
the
airplane.
Any
other
device plugged
into
these
receptacles
may
be
damaged.
REPORT:
VB-1110
ISSUED: JANUARY 8,
1981
7-20
REVISED:
SEPTEMBER 23, 1983