Hi, yesterday, just out of curiosity, I tried to play with the Flight Control shutoff switches and Split System breaker switch on the upper overhead panel (on the ground), but as I flipped the switches nothing happened (and no EICAS messages at all). Are they functional?

Thanks.

Were you on the ground or in Flight?   Maintenance switches are not active inflight

Hi Paul, I remember being on the ground, anyway it was during a quick general test of the airplane, I will retry tonight. If you say that those switches are functional, then maybe I did something wrong. Thank you!

They should be functional,  I will have to go back and recheck them now

The flight control switches work, while the SSB switch doesn't seem to work, nothing happens in any electrical condition (APU, EXT PWR, engines on), on the ground.

Any clue about that switch? Thanks.

The SSB switch is controlled by the BCU 1 and 2.  It can only be opened or closed manually under very specific circumstances.

From the AOM Vol 2

 

SPLIT SYSTEM BREAKER Switch
Push - (spring-loaded toggle, guarded) opens or closes split system breaker
Note: Operative on ground only.

It can only be opened or closed manually under very specific circumstances.

 

So maybe this is the key point. Thank you!