Omron NX-ECC201

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5 Designing the Power Supply System
NX-series EtherCAT Coupler Unit User’s Manual (W519)
5-4 Selecting External Power Supplies and Protective Devices
5
5-4-2 Selecting the I/O Power Supplies
This section describes how to select the I/O power supplies for the EtherCAT Slave Terminal.
Use an SELV power supply that meets the following conditions for the I/O power supply.
• Has overcurrent protection.
• Has double or reinforced insulation between the input and output.
• Has an output voltage of 5 to 24 VDC (4.5 to 28.8 VDC).
*1. Use an output voltage that is appropriate for the I/O circuits of the NX Units and the connected external
devices.
Recommended Power Supplies: S8JX Series (manufactured by OMRON)
Use the calculation method that is described in 5-3 Designing the I/O Power Supply System on page
5-9 and calculate the total current consumption from the I/O power supply and the required power sup-
ply capacity of the I/O power supply.
Unlike the Unit power supply, it is not necessary to use only one I/O power supply to supply power to
the entire Slave Terminal.
Precautions for Correct Use
Consider the inrush current when the power supply is turned ON and select an I/O power sup-
ply with sufficient extra capacity. The inrush current when power is turned ON may prevent the
I/O power supply from operating correctly.
Consider the following items when you select protective devices (e.g., breakers and fuses) to protect
against short circuits and overcurrents in external circuits.
• Protective device specifications (fusing, detection characteristics, steady current, inrush current, etc.)
• Inrush current when power is turned ON
Overcurrent is the current that flows when an excessive load is connected and one of the following rat-
ings is exceeded.
• For the Unit power supply, the rating of the NX Unit power supply capacity or of the current capacity
of the power supply terminals
• For the I/O power supply, the rating of the maximum I/O power supply current or of the current capac-
ity of the power supply terminals
Refer to 3-1-2 EtherCAT Coupler Unit Specifications on page 3-2 for the above ratings for the EtherCAT
Coupler Unit. For the ratings of NX-series power supply-related Units, refer to the NX-series System
Units User’s Manual (Cat. No. W523).
5-4-2 Selecting the I/O Power Supplies
Recommended Power Supplies
Calculating the Required Power Supply Capacity of the I/O Power
Supply
5-4-3 Selecting Protective Devices