@Smurf1976 A bit of a disaster, the Callide incident, doing this sort of work online a bit tricky.
But to have it take out the DC control cct's plus the emergency lighting and DC auxiliaries supplies seems a bit weird. Off one common board or dud batteries, certainly a mess and no wonder the Turbine blew up a 50+ton shaft spinning at 3,000rpm with no bearing oil supply isn't good.
An explosion at a central Queensland power station that left almost half a million people without power could not have been anticipated, according to a report into the incident.
The report found that on May 25, 2021, a new DC system with a battery charger had been commissioned and was being connected to the C4 unit.
"Voltage unexpectedly dropped to zero, causing a trip in the AC system," Mr Busine said.
"The loss of the AC system then prevented the recovery of the DC system."
This meant the power station unit could not disconnect from the grid or shut down safely.
"Ultimately the turbine generator went from generating electricity to consuming electricity," Mr Busine said.
"It became an unstoppable sequence of events which led to the emergency evacuation of the site ahead of the destruction of the generator."
The turbine generator spun, and this, alongside the loss of other critical systems like lubrication oil pumps, caused the explosion.
Mr Busine thanked staff for their handling of the incident.
No-one was injured.
"All this happened within seconds — what's important to understand also is that the control room went black," Mr Busine said.