Panasonic AFPXHEAD4, User Manual

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2.1 Wiring the Power Supply
2.1.1 Common Precautions
■
Selection of power supply
● Use a low noise power supply.
● The inherent noise resistance is sufficient for the noise superimposed on the power wires,
however, the noise can be attenuated further by using the insulation transformer or insulated
power supply.
■
Isolation of power supply systems
Isolate the wiring systems to the units, input/output devices, and mechanical power apparatus.
Circuit breaker
Mechanical
power
apparatus
Input/Output
devices
Insulated transformer
Insulated DC power supply
PLC
■
Power supply sequence
● The power supply sequence should be set up so that the power supply of the PLC turns off
before the power supplies for input and output.
● If the power supplies for input and output turns off before the power to the PLC, the control
unit will detect the input fluctuations and may begin an unscheduled operation.
2.1.2 Grounding
● Ground the unit to obtain sufficient noise suppression.
● The point of grounding should be as close to the PLC unit as possible. The ground wire
should be as short as possible.
● Sharing the ground with another device may have an adverse effect. Therefore, be sure that
grounding is dedicated.
● The grounding terminal should have a resistance of 100 Ω or less.
2.1 Wiring the Power Supply
2-2 WUME-FPXHAIO-01