ABB RELION REX640 Installation Manual page 7

Safety information
Dangerous voltages can occur on the connectors, even though the auxiliary voltage has been
disconnected.
Non-observance can result in death, personal injury or substantial property damage.
Only a competent electrician is allowed to carry out the electrical installation.
National and local electrical safety regulations must always be followed.
The frame of the protection relay has to be carefully earthed.
The protection relay contains components which are sensitive to electrostatic discharge.
Unnecessary touching of electronic components must therefore be avoided.
Whenever changes are made in the protection relay, measures should be taken to avoid
inadvertent tripping.