Siemens SIMATIC EMS400S PSB-S Operating Instructions Manual page 16

Safety instructions
Note
The safety concept for overvoltage protection described in this section has been tested and
approved by TÜV SÜD. You can find the technical report of the TÜV SÜD in the Internet
under entry ID 134200
(http://support.automation.siemens.com/WW/view/en/68156412/134200).
The documents belonging to the EMS400S plant controller are listed in the preface.
Note
High-frequency radiation, e.g. from cellular phones, may cause unwanted operating states in
the system.
Safety when working in and on electrical systems
No SELV (safety extra-low voltage)
The "SELV" identifier no longer applies when PSB-S modules are operated on two
Logo!Power power supply modules operating in serial mode, because the RAIL contact
conductors also operate on 48 V DC potential. The corresponding conductors carry a
dangerous live voltage.
Observe the following points to avoid danger:
• Attach a corresponding warning note to the LOGO!Power power supply modules:
• Do not start to work in and on electrical systems before you have isolated the equipment
• Verify that the EMS is isolated from power supply!
Only authorized persons are allowed to work in or on electrical equipment. The following
safety regulations for the prevention of electrical accidents apply in accordance with
DIN VDE 0105:
1. Isolation of the system from power
2. Securing the system against restart
3. Verification of isolation from power at all poles
4. Grounding and shorting the system
5. Covering or fencing off adjacent live parts
16
WARNING
"Caution! Dangerous output voltage! Components may only be installed or removed
while the power supply is shut down".
from the power supply!
Operating Instructions, 03/2014, A5E03474166-03
PSB modules