Oit ca ble routing 7, Other steps to im prove noise im mu nity 7, Oit cable routing – Maple Systems MAP460D User Manual

Page 7: Other steps to improve noise immunity

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• 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 operating 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

1010-0093, REV 03

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

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