Fig. 21 Threaded Hole Functional Earthing - Beckhoff C5240 Manual

All connected devices must be in SELV (Safety Extra Low Voltage)/PELV (Protective Extra Low Voltage)
circuits.
Protective earth
A protective conductor is included in the industrial PC's IEC socket for connecting the power supply.
Establish the low-resistance protective earth of the industrial PC via the voltage connection, thus avoiding
dangerous touch voltages.
If you have ordered the industrial PC with a 24 V power supply unit, a pin for protective earthing (PE) of the
device is included in the power supply socket. Here, too, establish the low-resistance protective grounding of
the industrial PC via the voltage connection and thus avoid dangerous touch voltages, e.g. if a 230 V line of
a neighboring device comes into contact with the housing of the PC in the event of a fault.
EMC
Hardware damage due to electromagnetic interference
Using the industrial PC without functional earthing can lead to hardware damage due to electromagnetic
interference.
• Only use the device with functional earth.
Electromagnetic compatibility (EMC) refers to the industrial PC's ability not to interfere with other devices and
equipment through electromagnetic interference, and not to be disturbed by electrical or electromagnetic
effects.
For this purpose, the industrial PC must comply with certain protection requirements. The industrial PC has
EMC interference immunity according to EN 61000-6-2. The EMC interference emission of the device meets
the requirements of EN 61000-6-4.
The functional earth is necessary for the EMC of the device. The functional earthing is established via the
ground connection between the threaded hole above the connection section and the central grounding point
of the rack in which the PC is installed.
If you have ordered the industrial PC with a 24 V power supply unit, you can choose between two grounding
points for functional earthing. Use either the threaded hole above the connection section or the grounding
bolt in the sheet metal on the power supply unit. Again, make the ground connection to the central grounding
point of the rack.
Use either a wide, flat ground strap or a round conductor with a minimum cross-section of 10 mm
ground connection. In the case of a round conductor, also use a cable lug with a ring and place the ring over
the grounding bolt.
Fig. 21: Threaded hole Functional earthing
C5240
NOTICE
Version: 3.0
Commissioning
2
for the
25