Design Method For Power Supply System With Through-Wiring; Selecting Power Supplies And Protective Devices; Selecting External Power Supplies; Selecting Protective Devices - Omron NXR Series User Manual

4 Designing the Power Supply System
4-3
Selecting Power Supplies and Protec-
tive Devices
This section describes how to select the external power supplies, i.e., Unit/input power supply and out-
put power supplies, and protective devices for the IO-Link Master Unit.
4-3-1

Selecting External Power Supplies

The following describes how to select the recommended power supplies for external power supplies
and their power supply capacity.
Recommended Power Supplies
Use an SELV power supply that meets the following conditions for the Unit/input power supply and
output power supply of the IO-Link Master Unit.
• Has overcurrent protection.
• Has double or reinforced insulation between the input and output.
• Has an output voltage of 24 VDC (20.4 to 26.4 VDC).
Recommended power supplies: S8VK-S Series (manufactured by OMRON)
Power Supply Capacity
Calculate the total current consumptions from the Unit/input power supply and output power supply of
the IO-Link Master Unit and the power supply capacity of each power supply according to the calcula-
tion methods described in the following sections.
• 4-2-2 Design Method for Direct Power Supply on page 4-7
• 4-2-3 Design Method for Power Supply System with Through-wiring on page 4-13
Precautions for Safe Use
Inrush current may flow in the Unit/input power supply and output power supply in the following
cases.
When power is turned ON.
When power supply to IO-Link devices is started.
When connected external devices are turned ON and OFF.
In addition, overcurrent may flow until the protection is activated when there is a short-circuit in
I/O cables. Consider these currents and select power supplies with sufficient extra capacity. The
inrush current may prevent the power supply from operating correctly, or cause the power sup-
ply to turn OFF.
4-3-2

Selecting Protective Devices

This section describes how to select protective devices (e.g., breakers and fuses) to protect against
short circuits and overcurrents in external circuits.
4-20
NXR-series IO-Link Master Unit for EtherCAT User's Manual (W640)