Connection   
6.1 Safety when connecting up 
  SCALANCE W778-1 / W738-1 
52  Operating Instructions, 03/2022, C79000-G8976-C450-07 
 
WARNING 
Lack of equipotential bonding 
If there is no equipotential bonding in hazardous areas, there is a risk of explosion due 
to equalizing current or ignition sparks. 
•  Ensure that equipotential bonding is available for the device. 
 
 
WARNING 
There is a risk of explosion due to unprotected cable ends in hazardous areas. 
•  Protect unused cable ends according to IEC/EN 60079-14. 
 
 
WARNING 
Improper installation of shielded cables 
There is a risk of explosion due to equalizing currents between the hazardous area and 
the non-hazardous area. 
•  Ground shielded cables that cross hazardous areas at one end only. 
•  Lay a potential equalization conductor when grounding at both ends. 
 
 
WARNING 
Insufficient isolation of intrinsically safe and non-intrinsically safe circuits 
Risk of explosion in hazardous areas 
•  When connecting intrinsically safe and non-intrinsically safe circuits, ensure that the 
galvanic isolation is performed properly in compliance with local regulations (e.g. IEC 
60079-14). 
•  Observe the device approvals applicable for your country. 
Notes for use in hazardous locations according to ATEX, IECEx, UKEX and CCC Ex 
If you use the device under ATEX, IECEx, UKEX or CCC Ex conditions you must also keep 
to the following safety instructions in addition to the general safety instructions for 
protection against explosion: