• A power line filter installed at the AC input to the OIT power supply is highly
recommended as a safeguard against conducted RF noise, which is often present
on factory power lines. The wires connecting the output of the power line filter
to the power supply should be kept as short as possible to minimize any
additional noise pickup. The case of the power line filter should be connected to
a quiet earth ground. The power line filter should have a current rating of at least
three amps with common mode and differential mode attenuation.
• The power supply that provides power to the OIT should not be used to power
switching relays or solenoids unless noise filter caps are connected to each relay.
1.3. OIT Cable Routing
• Always route the OIT communication cable and power cable away from any AC
voltage or PLC/host control wires.
• Never bundle the OIT cables together with 120 VAC power wires or with relay
wiring.
• Try to keep at least 8 inches (20 cm) of separation between the OIT cables and
other power wiring. If voltages greater than 120 VAC are used in the system,
greater separation is required.
• If the OIT cables must come near AC wiring, make sure they cross at 90 degrees.
• Running AC power wires in a separate grounded conduit is the preferred method
for electrical noise reduction.
• Keep the lengths of the OIT cables as short as possible. Do not coil excess cable
and place it next to AC powered equipment.
1.4. Other Steps to Improve Noise Immunity
• Always install the OIT’s rear cover. This provides a shield against electrical
noise which can be generated in the control panel by relays, motors, power lines,
and/or high frequency equipment. Ensure that all rear cover mounting screws
are properly secured.
• Any equipment used in the enclosure that operates at high frequency or high
current levels can be covered with a grounded metal shield.
INSTALLATION MANUAL
7
1010-0081A, REV 04
AC
AC
GND
N
L
WHITE
BLACK
N
L
G
AC
LINE FILTER
GREEN
WHITE TO
110VAC NEUTRAL
BLACK TO
110VAC LOAD(HOT)
TO EARTH
"QUIET" GROUND
POWER SUPPLY
GROUND
KEEP SHORT
Figure 2 Power Line Filter Connection
