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E3NW-CRT
User’s Manual
Section 4
Using th
e Dist
ribut
ed Sen
s
or Unit
Section 4
Distributed Sensor Unit Power Supply Specifications and Connections
Distributed Sensor Unit Power Supply Specifications and Connections
Precautions on Supplying Unit Power
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.
Unit Power Supply Specifications
Use a standard power supply that meets the following specifications.
We recommend using an OMRON S8JX-series power supply for the Unit power supply.
• 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.
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 the outputs and AC power supply and between the outputs and case
ground
