Beckhoff CP77 Series Manual page 20

Commissioning
The cabling of the panel PC in the control cabinet must be done in accordance with the standard EN
60204-1:2006 PELV = Protective Extra Low Voltage:
• The PE conductor (protective earth) and the "0 V" conductor of the voltage source must be on the
same potential (connected in the control cabinet).
• Standard EN 60204-1:2006, section 6.4.1:b stipulates that one side of the circuit, or a point of the
energy source for this circuit must be connected to the protective conductor system.
Peripheral devices connected to the device with their own power supply must have the same potential for the
PE and "0 V" conductors as the control panel (no potential difference).
20 Version: 3.4 CP77xx