Connection 
  6.1 Safety when connecting up 
SCALANCE W778-1 / W738-1 
Operating Instructions, 03/2022, C79000-G8976-C450-07 
51 
 
Damage to the device due to potential differences 
To fully eliminate the influence of electromagnetic interference, the device must be 
grounded. There must be no potential difference between the following parts, otherwise 
the device or other connected device could be severely damaged: 
•  Housing of the SCALANCE W device and the ground potential of the antenna. 
•  Housing of the SCALANCE W device and the ground potential of a device connected 
over Ethernet. 
•  Housing of the SCALANCE W device and the shield contact of the connected 
Ethernet cable. 
Connect both grounds to the same foundation earth or use an equipotential bonding 
cable. 
Safety notices on use in hazardous areas 
General safety notices relating to protection against explosion 
 
 
WARNING 
Do not connect or disconnect cables to or from the device when a flammable or 
combustible atmosphere is present. 
 
 
WARNING 
Do not press the reset button if there is a potentially explosive atmosphere. 
 
WARNING 
Unsuitable cables or connectors 
Risk of explosion in hazardous areas 
•  Only use connectors that meet the requirements of the relevant type of protection. 
•  If necessary, tighten the connector screw connections, device fastening screws, 
grounding screws, etc. according to the specified torques. 
•  Close unused cable openings for electrical connections. 
•  Check the cables for a tight fit after installation.