Connecting The Supply Voltage - Siemens SIMATIC S7-1500 System Manual

Connecting

6.5 Connecting the supply voltage

6.5 Connecting the supply voltage
24 V DC power supply
The SIMATIC Drive Controller is powered by an external 24 V DC power supply. Power
supply units from the SITOP family, for example, can be used.
Connection of an unsuitable power supply poses a danger to life from hazardous voltage
Configure the 24 V direct voltage as protective extra-low voltage.
A 24 V DC power supply to be connected to the interfaces must meet the requirements for a
protective extra-low voltage (PELV) pursuant to UL 61010. A backup fuse that trips within
120 milliseconds in the event of a short-circuit at an ambient temperature of 0 °C must also
be used.
When the power supply used comes primarily from OVC III circuits up to 600 V AC (line to
neutral voltage), the contact distance for the fuse or circuit with single-fault safety must be
3.0 mm pursuant to UL 61010.
If using an external power supply, make sure that the shutdown rating of the fuse
corresponds to the max. possible short-time short-circuit current of the power supply used.
Note
The ground potential and enclosure (PE) are connected over a low-impedance internal
connection. Therefore, please note the following:
• Insulation monitors are not permitted in the 24 V power supply.
• If you are using external power supplies (for example SITOP), you must connect the
ground potential to the protective conductor terminal (PELV).
• Suitably dimensioned potential equalization connections are required between the 24 V
power supply and all grounded, physically separate devices. You can find information on
potential equalization in Protective conductor and potential equalization, functional
ground (Page 85).
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WARNING
SIMATIC Drive Controller
System Manual, 11/2019, A5E46600094-AA