Originally Posted by
fiftypercentn1
Can someone with english as his first language please give me the definition of HOT BUS?
Depends on what's your first language....
In common electricians language, a "Hot Bus", or indeed any "hot" electrical circuit is simply a circuit that has power on it.
In aviation, it's come to mean a 'bus' that still has power on it, even when just about everything has been shut down.
Exactly like your car... you turn off the ignition and take the key out, but a few items will remain on a "hot bus", like the electrical door locks and the clock.
CJ