Configuration   
6.4 Protecting explosion-protected motors 
  SIRIUS Innovations - SIRIUS 3RU2 thermal overload relays / SIRIUS 3RB3 solid-state overload relays 
56  Manual, 09/2014, A5E03656507420A/RS-AA/002 
 
Protecting explosion-protected motors 
SIRIUS components meet a wide range of requirements for operation in hazardous areas 
and for switching and protecting components used in hazardous areas. 
Explosion protection types in accordance with ATEX Directive 94/9/EC 
3RB30/3RB31 solid-state overload relays and 3RU21 thermal overload relays are suitable 
for the overload protection of explosion-proof motors with protection type "increased 
safety" Ex e. 
The relays correspond to the requirements of EN 60079. 
3RB30/3RB31 solid-state overload relays and 3RU21 thermal overload relays are approved 
under Device Group II, Category (2) for overload protection of motors operated in Area "G" 
(areas in which potentially explosive gas, vapor, mist, and air mixes are present) and 
additionally in Area "D" (areas containing combustible dust). 
3RB30/3RB31 solid-state overload relays and 3RU21 thermal overload relays are not 
intended for installation in hazardous areas. 
When installed in hazardous areas, 3RB30/3RB31 solid-state overload relays and 3RU21 
thermal overload relays must be adapted to the corresponding explosion protection type. 
For 3RB30 and 3RB31 solid-state overload relays in sizes S00 and S0 (size S2 on request), 
the EC type examination certificate is available for Group II, 
Category (2) G [Ex e] [Ex d] [Ex px] and D [Ex t] [Ex p]. 
The number is PTB 09 ATEX 3001. 
For 3RU21 thermal overload relays in sizes S00 and S0 (size S2 on request), the EC type 
test certificate is available for Group II, Category (2) GD. 
The number is DMT 98 ATEX G001. 
More information and certificates for download are available on the internet 
(http://www.siemens.com/automation/service&support). 
More information on explosion protection (ATEX) can be found online 
(http://www.siemens.com/sirius/atex).