Rev
A2
LC900007
5
of
18
SAFETY
PRECAUTIONS/INSTALLATION
Step
Three
Make
a
Fail
‐
Safe
System:
Design
a
fail
‐
safe
system
that
accommodates
the
possibility
of
relay
or
power
failure.
If
power
is
cut
off
to
the
controller,
it
will
de
‐
energize
the
relay.
Make
sure
that
the
de
‐
energized
state
of
the
relay
is
the
safe
state
in
your
process.
For
example,
if
controller
power
is
lost,
a
pump
filling
a
tank
will
turn
off
if
it
is
connected
to
the
Normally
Open
side
of
the
relay.
While
the
internal
relay
is
reliable,
over
the
course
of
time
relay
failure
is
possible
in
two
modes:
under
a
heavy
load
the
contacts
may
be
“welded”
or
stuck
into
the
energized
position,
or
corrosion
may
buildup
on
a
contact
so
that
it
will
not
complete
the
circuit
when
it
should.
In
critical
applications,
redundant
backup
systems
and
alarms
must
be
used
in
addition
to
the
primary
system.
Such
backup
systems
should
use
different
sensor
technologies
where
possible.
While
this
manual
offers
some
examples
and
suggestions
to
help
explain
the
operation
of
FLOWLINE
products,
such
examples
are
for
information
only
and
are
not
intended
as
a
complete
guide
to
installing
any
specific
system.
Components:
LC52
‐
1001
‐
Single
input
with
dual
relays,
3.5
digit
LED
display
and
repeater
output.
Owner’s
Manual
Panel
DIN
Rail
Mounting:
The
controller
may
be
mounted
by
either
a
back
panel
using
two
screws
through
mounting
holes
located
at
the
corners
of
the
controller
or
by
snapping
the
controller
on
35
mm
DIN
Rail.
Note:
Always
install
the
controller
in
a
location
where
it
does
not
come
into
contact
with
liquid.