6
of
18
LC900007
Rev
A2
GETTING
STARTED
Step
Four
Features
of
a
Single
Input
High
or
Low
Relay:
Single
Input
Relays
(Relay
1
or
Relay
2
w/
latch
turned
OFF)
are
designed
to
switch
from
a
single
set
‐
point.
It
turns
its
internal
relay
ON
or
OFF
(as
set
by
the
invert
switch)
in
response
to
the
presence
of
liquid,
and
changes
the
relay
status
back
again
when
the
sensor
is
dry.
High
Alarm:
Invert
is
OFF.
Relay
will
energize
when
the
level
rises
above
the
high
alarm
setting
and
will
de
‐
energize
when
it
drops
below
the
high
alarm
setting.
Low
Alarm:
Invert
is
ON.
Relay
will
energize
when
the
level
drops
below
the
low
alarm
setting
and
will
de
‐
energize
when
it
rises
above
the
low
alarm
setting.
Single
input
high
or
low
relays
may
be
used
with
any
device
that
outputs
a
4
‐
20
mA
signal.
The
relay
is
a
single
pole,
double
throw
type;
the
controlled
device
can
be
connected
to
either
the
normally
open
or
normally
closed
side
of
the
relay.
A
time
delay
from
0.15
to
60
seconds
can
be
set
before
the
relay
responds
to
the
sensor
input.
Typical
applications
for
single
input
relays
are
high
level
or
low
level
switch/alarm
operations
(opening
a
drain
valve
whenever
liquid
level
rises
to
a
set
‐
point)
and
over
‐
flow
protection
(turning
off
a
pump
or
sounding
an
alarm
when
a
high
level
is
reached).
Features
of
a
Latching
Relay
(automatic
fill
or
empty):
The
latching
relay
(relay
2
only)
is
designed
to
switch
a
relay
on
and
off
at
two
different
levels.
It
turns
its
internal
relay
ON
or
OFF
(as
set
by
the
invert
switch)
in
response
when
the
level
is
above
the
high
setting
or
below
the
low
setting.
The
relay
will
not
change
its
state
when
the
level
is
between
the
high
and
low
setting.
Automatic
Empty:
Latch
is
ON
&
Invert
is
OFF.
Relay
will
energize
when
level
reaches
high
setting
(both
settings
are
submersed).
Relay
will
de
‐
energize
when
level
is
below
the
bottom
setting
(both
settings
are
dry).
Automatic
Fill:
Latch
is
ON
&
Invert
is
ON.
Relay
will
energize
when
level
is
below
the
bottom
setting
(both
switches
are
dry).
Relay
will
de
‐
energize
when
level
is
above
the
high
setting
(both
settings
are
wet).