Beckhoff CP22 Series, Manual

Page: 28 / 53

Commissioning
CP22xx 28 Version: 2.0
4.3.2 Grounding the Panel PC
Potential differences are minimized and electrical currents are diverted to the ground through grounding or
potential equalization of electronic devices. This is to prevent dangerous touch voltages and electromagnetic
interference.
Protective earth
The protective earthing of a device serves to avoid dangerous touch voltages. According to the EN 60204-1
standard (Chapter 8 Equipotential bonding), protective earthing is required if:
• the device exceeds dimensions of 50 x 50 mm,
• the device can be touched or encompassed over a large area,
• contact between the device and active parts is possible,
• an isolation fault may occur.
Establish low-resistance protective earthing of the Panel PC via the voltage connection to avoid dangerous
touch voltages. There is a pin in the voltage socket for the protective earth (PE).
EMC
NOTE
Hardware damage due to electromagnetic interference
The use of the Panel PC without a functional earth can lead to material damage due to electromagnetic in-
terference.
• Only use the device with functional earth.
Electromagnetic compatibility (EMC) of the Panel PC includes on the one hand not affecting other devices
and equipment by electromagnetic interference and on the other hand not being disturbed by electrical or
electromagnetic effects itself.
To do this, the Panel PC must comply with certain protection requirements. The Panel 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. You establish functional earthing via the
grounding connection between the grounding bolt in the connection section on the rear side of the Panel PC
(see Fig. 17) and the central grounding point of the control cabinet in which the PC is installed. Use wires
with a cross-section of at least 4 mm
2
or a flat conductor for the ground connection, as the circumference of
the conductor should be as large as possible.
Fig. 17: CP22xx_grounding bolt functional earthing