Omron E3NW-CCL, User Manual

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A Appendices
A - 28 E3NW-CCL CC-Link Digital Sensor Communications Unit User’s Manual (E431)
Consider the following points on the allowable current and voltage drop on cables and connectors and
the placement of the power supply used to supply power to the Units.
 Precaution on Cable Voltage Drop
Make sure that the power supply voltage to the Distributed Sensor Unit farthest from the power
supply is within the allowable fluctuation range.
 Supplying Power to Units from Multiple Power Supplies
Using multiple power supplies to supply power can allow you to reduce the line current, reduce
voltage drop, and decrease cable size. It also helps to maintain system stability in the event of a
power supply problems.
 Power Supply Problems
You must decide how to place your power supplies and how to group them depending on whether
you want to stop the entire system when a power supply problem occurs or if you want to avoid
stopping the entire system when possible.
If you want to avoid stopping the entire system, install power supplies in multiple locations and
divide the Distributed Sensor Units into groups.
This will also help to reduce voltage drop and enable you to use smaller cables.
Use a standard power supply that meets the following specifications.
We recommend using an OMRON S8JX-series power supply for the Unit power supply.
Precautions for Correct Use
• When calculating the output current for the Unit power supply, always include the current
consumption of the E3NW-DS and the current consumption of all Sensor Amplifier Units in the
Unit power supply consumption current.
• Make sure that the power supply has sufficient capacity to handle the inrush current when the
system is started.
A-4-4 Distributed Sensor Unit Power Supply Specifications and
Connections
Precautions on Supplying Unit Power
Unit Power Supply Specifications
Item Specification
Output voltage 24 VDC ± 10%
Output ripple 600 mVp-p
Output current
Must be able to supply current that is higher than the total sum of the current
consumed by all Slave Units.
Isolation Between output and AC power supply and between output and frame ground