A customer of mine with a large facility had a horrendous problem a week ago. An oil heater used to heat-trace failed and caught fire. The place got cranking. Every fire engine in a city of 150k was called in (14) and they had about 20 hose lines going.
General mayhem.
Seat of the fire.
I-Beam.
This was odd. All the overhead motors were gone. Well, their housings anyway, but they all left their rotors standing on end on the ground under where they were mounted. What happened to the housings?
VFD's didn't fair well.. Everything around them looked okay but if you open breaker panels you see all the breakers have slagged back into the panels.
Here's where good old bungling PG&E comes in. They got there fairly quickly and when asked to drop the power they promptly did. TO THE BUILDING ACROSS THE PARKING LOT NEXT DOOR!! They left the single, pole mounted 300kVA three phase transformer that runs only the facility energized. Fairly soon one cut-out blew on it leaving 2 phases energized into the structure until the fire was out.
BUT WAIT! It gets better! After all those engines had pumped tens of thousands of gallons on the fire for more than three and a half hours the question "How can this still be burning!!??" was raised by the fire staff. The answer is simple..
PG&E didn't bother to turn off the 2-1/2 inch 3.5psi gas line into the seat of the fire. Even though it is literally the first thing one comes to when driving up to the facility. It's estimated the damage was double it would've been if the gas had been turned off when the PG&E representative arrived.
Keith Cress
kcress -
General mayhem.
Seat of the fire.
I-Beam.
This was odd. All the overhead motors were gone. Well, their housings anyway, but they all left their rotors standing on end on the ground under where they were mounted. What happened to the housings?
VFD's didn't fair well.. Everything around them looked okay but if you open breaker panels you see all the breakers have slagged back into the panels.
Here's where good old bungling PG&E comes in. They got there fairly quickly and when asked to drop the power they promptly did. TO THE BUILDING ACROSS THE PARKING LOT NEXT DOOR!! They left the single, pole mounted 300kVA three phase transformer that runs only the facility energized. Fairly soon one cut-out blew on it leaving 2 phases energized into the structure until the fire was out.
BUT WAIT! It gets better! After all those engines had pumped tens of thousands of gallons on the fire for more than three and a half hours the question "How can this still be burning!!??" was raised by the fire staff. The answer is simple..
PG&E didn't bother to turn off the 2-1/2 inch 3.5psi gas line into the seat of the fire. Even though it is literally the first thing one comes to when driving up to the facility. It's estimated the damage was double it would've been if the gas had been turned off when the PG&E representative arrived.
Keith Cress
kcress -