Connection   
5.2 Power supply 
  SCALANCE W774-1 /W734-1 
38  Operating Instructions, 07/2020, C79000-G8976-C325-14 
General notes on use according to ATEX and IECEx 
 
 
WARNING 
DO NOT CONNECT OR DISCONNECT EQUIPMENT WHEN A FLAMMABLE OR 
COMBUSTIBLE ATMOSPHERE IS PRESENT. 
General notes on use in hazardous areas according to UL-HazLoc 
 
 
WARNING 
You may only connect or disconnect cables carrying electricity when the power supply 
is switched off or when the device is in an area without inflammable gas 
concentrations. 
This equipment is suitable for use in Class I, Division 2, Groups A, B, C and D or non-
hazardous locations only. 
This equipment is suitable for use in Class I, Zone 2, Group IIC or non-hazardous 
locations only. 
5.2  Power supply 
Note 
Galvanic isolation of the power supply unit
 
strength according to IEEE 802.3, the supplying 24 V power supply 
unit must be galvanically isolated with a dielectric strength of 1500 VAC. The galvanic 
isolation must also not be bridged by other devices connected to the same power s
upply