Siemens Sentron 3VA Manual page 349

Terminating test mode
If the <SET> button is not pressed for a period of three minutes after selection of an output,
test mode is terminated automatically and the EFB300 reverts to operating mode.
Alternative method:
After working through the entire menu structure (only the LED labeled "ACT" flashes), press
the <SET> button for longer than 2 seconds.
3VA molded case circuit breakers with UL and IEC certification
Manual, 01/2019, L1V30435333-01
Accessories
4.9 EFB300 external function box
347