Siemens SIRIUS 3RT Manual page 291

Manual operation of the contactor relays
With 3RT10/14 air-break contactors, the lateral auxiliary contacts can be operated for test
purposes by pressing the auxiliary switch receptacle / switch position indicator on the front.
By doing this the main contacts would also touch, without resulting in contact resilience.
NOTICE
Hazardous voltage
It must be ensured that the contactors are disconnected from the power system.
Switching order of auxiliary contacts
When contactors are switched on, with standard auxiliary switches the NC contacts are
opened first, then the NO contacts are closed.
Figure 9-7
SIRIUS - SIRIUS 3RT Contactors/Contactor assemblies
Manual, 09/2017, A5E03656507120A/RS-AE/006
Switching auxiliary contacts
Accessories
9.3 Auxiliary switch blocks
291