6
Installation
and Operation
EDBC250SIO | 2.0
166
6.3
Electrical Installation
WARNING
Potentially hazardous failures due to wrong voltages supplied
Supplying the wrong voltages may damage or destroy the unit and may provoke
potentially hazardous failures.
Preventive measures:
Only use PELV/SELV-ready power supply units to EN50178 or EN60950-1 to
supply 24 VDC to
o
the I/Os of Safety I/O-module
o
the bus couplers or compact PLCs that Safety I/O-modules are con-
nected to
o
the sensors and actuators connected to the Safety I/O-modules.
Check that your upstream bus coupler or the compact PLC is protected
against reversing the 24 V supply voltage.
Only use the GND terminal to connect the power supply unit to earth (PELV
system). Do not use earthing variants that connect earth to +24V.
Remember that, even in case of a fault, a maximum voltage of U max. < 33 V
may be supplied to these assemblies.
Do not reuse but replace units operated on voltages > 33 V because such
voltages may irreversibly damage the unit.
To ensure that there is as little interference as possible, install a central
power supply point and establish a star topology of as short wires as possi-
ble between the central point and the block of c250-S modules.
CAUTION
Danger caused by improper installation under voltage
Failure of Lenze’s Safety I/O-module module
Always de-energise Lenze’s Safety I/O-module module before installing it.
6.3.1
Earthing
WARNING
Danger of malfunction caused by EMC interference!
Improperly installing the modules may provoke malfunction of the modules by
EMC interference.
Preventive measures:
Properly earth the module.
Look at the entire chain, i.e.: earth the module, DIN rail, electrical cabinet
etc.
Check the earthing in conformity with VDE 0100.
Connect the c250-S modules to earth by attaching the metal housing to functional earth. Since
the functional earth connector dissipates HF and surge currents, it is of utmost importance for
the module's noise immunity.