It sounds like sloppy installation work in the central office. The normal standard is to connect the equipment to a battery string that supplies -48 volts at continuous loads of nearly 5,000 amps. The strings are charged by a rectifier bank from commercial electric power. If the commercial power is lost, a gas turbine or diesel electric generator fires up automatically. Once the emergency generator stable, it takes over charging the batteries until the commercial power is restored. Most central offices keep 30 days of fuel in reserve and test the emergency generator every 30 days.
Can you tell I'm a former central office equipment engineer?
I will remember your expertise, what caused the smoke in the command center when there was no fire?