Installation
Marathon
Series
FA/FR
19
5.4
Installing
the
Electronics
Housing
The
distance
between
the
electronics
housing
and
a
computer
(via
RS485
cable)
can
be
up
to
1200
m
(4000
feet).
This
allows
ample
distance
from
the
harsh
environment
where
the
sensing
head
is
mounted
to
a
control
room
or
pulpit
where
the
computer
is
located.
For
reliable
performance
it
is
recommended
that
the
power
supply
be
no
more
than
60
m
(200
feet)
away!
Following
you
can
see
installation
examples
shown
with
two
representative
cable
types.
A
4
‐
wire
cable
is
used
to
wire
the
24
VDC
power
supply
and
one
output
of
the
electronics
housing.
A
coated
12
‐
wire
cable
is
used
to
wire
all
inputs
and
outputs
of
the
electronics
housing.
Sometimes
in
cable
both
sets
of
twisted
‐
pair
wires
have
drain
wires
inside
their
insulation.
These
drain
wires
must
be
assembled
and
connected
to
the
terminal
labeled
SHIELD
(bare).
Also
connect
the
earth
ground
to
the
SHIELD
(bare)
terminal.
The
following
figure
shows
how
to
configure
the
drain
wires
of
both
4
‐
and
12
‐
wire
cables
before
connecting
to
the
sensor
and
RS485/RS232
converter.
Figure
14:
Configuring
the
Sensor
Cable
The
complete
wiring
must
have
only
one
common
earth
ground
point!
Cables
can
be
run
to
the
electronics
enclosure
through
conduit
or
fastened
using
the
a
compression
fitting.
Once
you
run
the
cable
into
the
enclosure,
attach
the
color
‐
coded
bare
wires
to
the
terminals.
Use
the
following
figure
(or
diagram
on
underside
of
lid)
as
a
wiring
guide.
Note
that
the
terminal
blocks
in
the
electronics
enclosure
can
be
“popped”
out
for
easy
wire
connections.
Twist braided shield and two drain wires from
the two twisted pairs together
Attach to SHIELD
in electronics housing
Earth Ground
Earth Ground
12-wire cable
4-wire cable
To electronics housing
To electronics housing
Attach to SHIELD
in electronics housing
e.g.
to power supply,
to RS232/485 converter,
other inputs/outputs
e.g.
to power supply,
0/4 – 20 mA current output