Omron NX Series Hardware User Manual

I/O power supply voltage at (5) = I/O power supply voltage on I/O power supply terminals − Voltage drop per
Unit × Number of Units passed through
= 24.00 V − 0.06 V × (5 − 1 Units)
= 23.76 V
Design to Separate the I/O Power Supply
If the I/O power supply voltages of the connected external devices are different, connect an Additional
I/O Power Supply Unit at the point where the I/O power supply voltage changes and then perform sim-
ilar calculations to design a system that meets the power supply conditions. The same method is used
to separate the power supply systems. Connect an Additional I/O Power Supply Unit at the point
where the power supply systems to be separated and then perform similar calculations to design the
overall system to meet the power supply conditions.
4-3-3
Designing the I/O Power Supply from External Sources
Unlike supplying power from the NX bus, there is no specific design method for supplying I/O power
from external sources.
Calculate the total current consumption from the I/O power supply for the NX Units to be supplied
power from an external source.
Refer to the user’
s manuals of the NX Units for the total current consumption from the I/O power sup-
ply.
4-3-4
Restrictions on Inrush Current for ON/OFF Operation
This section describes the restrictions on inrush current from the I/O power supply that occurs when
connected external devices turn ON and OFF.
Inrush Current Restrictions
If inrush current to the I/O power supply occurs when a connected external device turns ON or OFF,
do not allow the effective value of the I/O power supply current to exceed the following rated values
when the inrush current is added to the current consumption from the I/O power supply.
•
Maximum I/O power supply current
• Current capacity of power supply terminals for the I/O power supply
Also, maintain the peak inrush current 20 A maximum and maintain the pulse width 1 s maximum.
Refer to 4-4-3 Selecting Protective Devices on page 4-25 for the rated values of the items when the
CPU Rack is used.
Calculating the Effective Value of the I/O Power Supply Current
The formula to calculate the effective value of the I/O power supply current, Irms, is given below.
Irms= Ip
2
×
D+Ia
2
×
(1-D)
(D=τ/T)
• Ip: Peak inrush current (A)
• Irms: Ef
fective value of I/O power supply current (A)
4 Designing the Power Supply System
4-20
NX-series NX502 CPU Unit Hardware User's Manual (W629)

Omron NX Series Specifications

General

Brand	Omron
Model	NX Series
Category	Controller
Language	English