6 | MAP450D |
•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.
POWER SUPPLY
"QUIET" GROUND |
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| KEEP SHORT |
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TO EARTH |
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GROUND |
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| GREEN | GND |
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WHITE TO | N | N | WHITE | AC |
110VAC NEUTRAL |
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| G | AC |
| AC |
| LINE FILTER |
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BLACK TO |
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L | L | BLACK |
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110VAC LOAD(HOT) |
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Figure 2 Power Line Filter Connection
•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 host controller 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.