Wiring The Power Supply; Common Precautions - Panasonic FP7 Series User Manual

Installation and Wiring

4.2 Wiring the Power Supply

4.2.1 Common Precautions

 To avoid the influence of noises
• 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 isolation transformer.
• Also, twist the power supply cables to minimize adverse effects from noise.
 Keep the power supply wiring separate
Wiring to the CPU unit, input devices, and power equipment should have separate wiring
systems.
 Measures regarding power supply sequence (start up sequence)
• Have the power supply sequence such that the power supply of PLC turns off before the
power supply for input and output.
• If the input/output power supplies are turned off before the power PLC, the CPU unit will
detect the input fluctuations and may begin an unscheduled operation.
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