Signal type
Meaning
V
Supply voltage
GND
Protective ground (reference potential)
Note
Digital and analog signals must not be laid together within a cable.
12.3.4.2
X1 power supply
Properties
This interface is intended exclusively for the connection of the external 24 V power supply.
On the module side, the power supplies are protected against:
• Polarity reversal
• Short-circuit (elec. current limitation of the outputs)
• Overload (self-restoring PTC fuse - Multifuse)
Requirements placed on the DC power supply
WARNING
Inadequately fused supply cables can be life-threatening
In the case of supply lines > 10 m, protectors must be installed at the device input in order to
protect against lightning (surge).
The DC power supply must be connected to the ground/shield of the I/O module for EMC and/
or functional reasons. For EMC reasons, this connection should only be made at one point; see
also EMC Installation Guide.
Table 12-34 Requirements of the DC power supply
Rated voltage
According to EN 61131-2
24 VDC
Voltage range (average value)
20.4 VDC to 28.8 VDC
Voltage range (dynamic)
18.5 to 30.2 VDC
Voltage ripple peak-to-peak
5% (unfiltered 6-pulse rectifi‐
cation)
Ramp-up time at POWER ON
Any
Non-periodic overvoltages
≤ 35 V
Duration of overvoltage
≤ 500 ms
Recovery time
≥ 50 s
Events per hour
≤ 10
Connectable components
12.3 PP 72/48D PN 2/2A PN
NCU 1740
Equipment Manual, 10/2021, A5E51087503B AA
133