Omron PROFINET NX-PNC202, User Manual

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5 Designing the Power Supply System
5 - 14
NX-series PROFINET Coupler Unit User’s Manual (W623)
power supply systems are to be separated and then perform similar calculations to design the overall
system to meet the power supply conditions.
Unlike supplying power from the NX bus, there is no specific design method for supplying IO power
from external sources.
Calculate the total current consumption from the IO 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 IO power supply.
This section describes the restrictions on inrush current from the IO power supply that occurs when
connected external devices turn ON and OFF.
If inrush current to the IO power supply occurs when a connected external device turns ON or OFF, do
not allow the effective value of the IO power supply current to exceed the following rated values when
the inrush current is added to the current consumption from the IO power supply.
• Maximum IO power supply current
• Current capacity of power supply terminals for the IO power supply
Do not allow the inrush current to exceed the values given in the following table.
The formula to calculate the effective value of the IO power supply current, Irms, is given below.
• Ip: Peak inrush current (A)
• Irms: Effective value of IO power supply current (A)
• Ia: Total current consumption from the IO power supply (A)
• D: Inrush current duty
•

: Inrush current pulse width (s)
• T: Inrush current period (s)
5-3-3 Designing the IO Power Supply from External Sources
5-3-4 Restrictions on Inrush Current for ON/OFF Operation
Inrush Current Restrictions
Unit Model Peak value Pulse width
PROFINET
Coupler Unit
NX-PNC202 50 A 1 s
Calculating the Effective Value of the IO Power Supply Current
Irms= Ip
2
×D+Ia
2
×(1-D)
(D=
τ
/T)