20
MAINTENANCE
(continued)
Step
Seven
Testing
the
installation:
1.
Power:
Turn
on
power
to
the
controller
and/or
power
supply.
2.
Immersing
the
switch:
Immerse
the
sensing
tip
in
its
application
liquid,
by
filling
the
tank
up
to
the
switches
point
of
actuation.
An
alternate
method
is
to
hold
a
cup
filled
with
liquid
up
to
the
switch's
tip.
3.
Test:
With
the
switch
being
fluctuated
between
wet
and
dry
states,
the
switch
indicator
light
in
the
controller
should
turn
on
and
off.
If
the
controller
doesn't
have
an
input
indicator,
use
a
voltmeter
or
ammeter
to
ensure
that
the
switch
produces
the
correct
signal
(see
below).
4.
Point
of
actuation:
Observe
the
point
at
which
the
rising
or
falling
fluid
level
causes
the
switch
to
change
state,
and
adjust
the
installation
of
the
switch
if
necessary.
Example:
Testing
the
LVU
‐
150
series
with
a
Multimeter
set
to
read
current
(mA).
When
wired
NO
[Red
to
(+)],
the
meter
will
read
5mA,
±1mA
when
dry
and
will
read
20mA,
±1mA
when
wet.
Example:
Testing
the
LVU
‐
150
series
with
a
multimeter
set
to
read
resistance
(ohms).
When
wired
NO
[Red
to
(+)],
the
meter
will
read
O.L
when
dry
and
will
read
some
small
amount
of
resistance
(ex.
0.2
Ohms)
when
wet.