Grounding The Panel Pc; Fig. 18 Grounding Bolt For Functional Earthing - Beckhoff CP22 Series Manual

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 grounding of a device serves to avoid dangerous touch voltages. According to the EN
60204-1 standard (Chapter 8 Potential equalization), protective grounding is required if:
• the device exceeds dimensions of 50 mm x 50 mm,
• the device can be touched or encompassed over a large area,
• contact between the device and active parts is possible,
• an insulation 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
Hardware damage due to electromagnetic interference
The use of the device without a functional earth can lead to material damage due to electromagnetic
interference.
• Only use the device with functional earth.
Electromagnetic compatibility (EMC) of the device 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 device must comply with certain protection requirements. The device 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. 18) 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
the conductor should be as large as possible.
Fig. 18: Grounding bolt for functional earthing
CP22xx
NOTICE
2
or a flat conductor for the ground connection, as the circumference of
Version: 2.9
Commissioning
29