Protective Devices - Omron sysmac NX Series User Manual

4 Installation and Wiring
4-6-3

Protective Devices

This section describes the protective devices to protect against short circuits and overcurrents of ex-
ternal circuits.
Overcurrent means the current that flows when an excessive load is connected and one of the follow-
ing ratings is exceeded.
Unit name of supplying
Unit
Additional NX Unit Power
Supply Unit
Additional I/O Power Sup-
ply Unit
*1. When the Additional I/O Power Supply Unit is connected to the NX1P2 CPU Unit, use the I/O power supply
current at 4 A or less, regardless of the Additional I/O Power Supply Unit specifications.
Refer to A-1 Data Sheet on page A-2 for details on the ratings for NX-series power supply-related
Units.
For the rating of the CPU Unit, Communications Coupler Unit, or Communication Control Unit that can
supply I/O power, refer to the following manuals depending on the connected Unit.
• CPU Unit Hardware User's Manual
• User's manual for the Communications Coupler Unit
• User's manual for the Communication Control Unit
Refer to the user's manual for the connected Communications Coupler Unit or Communication Control
Unit for the ratings of the Communications Coupler Unit or Communication Control Unit that can sup-
ply I/O power.
Precautions for Safe Use
The I/O power supply current for the CPU Rack with an NX-series CPU Unit should be within
the range specified for the CPU Unit model. For example, use the NX1P2 CPU Unit with a cur-
rent of 4 A or less. Using the currents that are outside of the specifications may cause failure or
corruption. Refer to the user's manual for the connected CPU Unit for the I/O power supply cur-
rent for the CPU Unit model.
 Selecting Protective Devices
For selecting the protective devices, refer to the following manuals depending on the connected
Unit.
4-38
Connecting destination
of supplying Unit
•
CPU Unit
•
Communications Cou-
pler Unit
•
Communication Control
Unit
NX1P2 CPU Unit
•
NX502 CPU Unit
•
NX102 CPU Unit
•
Communications Cou-
pler Unit
•
Communication Control
Unit
Rated item
NX Unit power supply Less than the rating of
capacity Additional NX Unit Pow-
er Supply Unit
Current capacity of pow-
er supply terminals
Maximum current of I/O
4 A max.
power supply
Current capacity of I/O
power supply terminals
Maximum current of I/O Less than the rating of
power supply Additional I/O Power
Supply Unit
Current capacity of I/O
power supply terminals
NX-series System Units User's Manual (W523)
Rating
*1