Siemens SIMATIC MV500 Operating Instructions Manual page 30

Safety notes
System expansions
Install only system expansions that are intended for this device. Installing other expansions
can damage the system or violate the safety provisions and regulations for radio interference
suppression. You can obtain information on system expansions suitable for installation from
the technical customer service or from the sales office responsible for your area.
NOTICE
Invalidation of the warranty
Any damage to the device caused by installing or replacing system expansion products will
void the warranty.
NOTICE
Voltage can destroy electrostatic-sensitive modules
The device contains modules that are sensitive to electrostatic discharge. ESD devices can be
destroyed by voltages well below the threshold of human perception. Such voltages occur if
you touch a component or electrical connectors of a module without first discharging the
static from your body. The damage caused by overvoltage on a module cannot normally be
detected immediately and only becomes apparent after a longer period of operation.
Measures for protecting against discharge of static electricity:
• Before working with modules, make sure that you discharge static from your body, for
• The devices and tools used must also be free of static charges.
• Interrupt the power supply.
• Pick up the modules only on their edges and do not touch any pins or printed
Connecting the 24 V DC power supply
Requirement: Safe extra low voltage
The device should only be connected to a 24 V DC power supply which satisfies the
requirements of safe extra low voltage (SELV).
When the device is operated on a wall, in an open rack or other similar locations, an NEC
Class 2 current source is needed for compliance with UL requirements (according to
UL 60950-1). In all other cases (according to IEC/EN/DlN EN 60950-1), a current source with
limited power (LPS = Limited Power Source) is required.
24 V DC power supply (19.2 to 28.8 V)
The generation of the 24 V DC supply voltage by the line-side power supply must be
implemented as functional extra-low voltage with safe electrical isolation (floating)
according to IEC 80364-4-41, or as SELV according to IEC/EN/DlN EN 60950-1 and
LPS/NEC class 2.
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example by touching a grounded object.
conductors.
WARNING
Operating Instructions, 03/2021, C79000-G8976-C494-05
SIMATIC MV500