Yesterday morning a rare, yet exciting occurrence happened at work. There was a massive switchgear failure at one of our substations near campus. More specifically, it was Bus 2 failure which knocked out four feeders and hundreds, if not thousands of customers for about an hour before we switched the load onto different substations.
The switchgear that failed was installed in 1972 and was in rough shape since it was so old. Overtime, insulation breaks down and that combined with the all-day rain yesterday made for the perfect storm. Things started at about 10:00 when I saw the lights dip a bit and low voltage alarms started to come in on my display from all over the city. This is common when a bus has failed, because the high fault current causes the voltage to drop.
One of our wireman was at the gate of the substation for an unrelated reason when he heard this hissing sound from inside the switchgear and then a loud bang and then a bunch of breakers opening at once. Then he saw smoke and fire coming out of the backside of the switchgear. He grabbed the fire extinguished and quickly put out the flames. Other crews started to arrive and they thought they had isolated the part that failed, so we attempted to energize the bus again to restore load to the rest of the feeders. We closed the main breaker remotely from downtown in the bunker where I and like 15 other "high-ups" in the department were. Everything seemed to be OK...for about 30 seconds. My boss was talking to one of the crew members and while he was on the phone we heard this crash and a low rumble. And the guy on the phone said "I didn't work." Apparently, the door blew off the backside of the switchgear and flames of all colors blew out like 6 feet. Our crews were running for the fences I was told. Luckily no one was injured because everyone was in the clear when it happened. But now we have a very expensive fix on our hands and since the equipment is so old, we need to get a lot of custom parts made.
After looking at the damage, there was molten aluminum on the floor because the fire got so hot!
Here is a picture of the inside of one of the cubicles (all the black is char from the fire, usually it's silver):
Yes, I know, I haven't put up a blog about our NC trip yet. I apologize. Hopefully soon!
The crew has got to start winning again. This is no time for lolly gagging!
3 comments:
Was it a Main Bus B Undervolt like in Apollo 13? Man that is INTENSE.
I'm imagining you calmly monitoring the situation from the comfort of mission control, while smoking a cigar and making electrical engineering jokes.
Actually, when the bus failed it caused Main Bus Undervolts at a lot of other substations, so yeah, it's kind of like that :-)
Yeah, we calmly monitor the situation, it's usually very loud and intense downstairs during major problems because we're all on the raadios talking to the crews and telling them what to do next. Wish I could smoke a cigar! and there is the random high-brow electrical engineering joke here and there.
bad day at the office = awesome day at the office
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