SIRIUS 3RT2 contactors/contactor assemblies 
  2.7 Accessories 
SIRIUS Innovations 
System Manual, 01/2011, A8E56203870002-03 
185 
2.7.6  Mechanical latch 
2.7.6.1  Description 
The mechanical latch for the 3RT2.2 power contactors ensures that the contactor remains 
switched on even if there is a voltage failure. The release coil has an ON period of 100%.  
Table 2- 38  Versions of the mechanical latch 
Design of the mechanical latch  Order number 
24 V AC/DC  3RT2926-3AB31 
110 V AC/DC  3RT2926-3AF31 
230 V AC/DC  3RT2926-3AP31 
 
2.7.6.2  Mounting/Disassembly 
 
Table 2- 39  Mounting the mechanical latch 
Step  Operating instruction  Image 
1 / 2  When snapping on, the switch position 
indicator's rod must be unlocked. Unlock 
the rod by pressing on the switch position 
indicator and pushing the rod into the 
mechanical latch as far as it will go. 
3  Snap the mechanical latch onto the center 
of the contactor until it engages.