Siemens SIWAREX WP321 Manual page 22

Mounting
5.2 EMC-compliant setup
Rule 5: Homogeneous reference potential
● Create a homogeneous reference potential and ground all electrical equipment.
● Use sufficiently dimensioned equipotential bonding conductors if potential differences
exist or are expected between your system components. Equipotential bonding is
absolutely mandatory for applications in hazardous areas.
22
SIWAREX WP321
Manual, 07/2014, A5E33715669A-02