Another horror story:
Several years ago, one of the local refineries installed an 8,000 horsepower motor as the driver for a coke-cutting pump. This a pretty substantial sized motor. It drives a high pressure water pump that cuts petroleum coke from the inside of the huge vessel in which it is produced. Petroleum coke is almost pure carbon and is the leftovers after all the other useful and more profitable stuff has been extracted from crude oil.
For you power geeks, we fed the motor from a 13,800 volt bus through a captive 13,800 – 4160-volt captive transformer, using the 13,800-volt circuit breaker as a motor controller. As the high voltage power systems guy, I saw to the commissioning of the new circuit breaker, the protective relaying, including differential protection for the transformer and a Multilin relay for the motor protection.
The motor itself was located a thousand feet away through the unit. We did the normal tests on the electrical stuff on the motor. I was confident of the integrity of all the electrical components in the system.
Comes the day we’re supposed to run the motor for the first time. We have the usual crowd: electrical, mechanical and production folks all over the place to see the new toy run. It’s a zoo. I station myself in the switchgear building near my pet circuit breaker.
First start is a “bumpâ€? for rotation check. Radio communications from my end to radio on the other end, and they punch the start button and the stop button in rapid sequence, just enough to make sure the motor turns in the right direction. These motors can be wired to run in either direction, but the equipment it’s connected to will only work in one direction. I hear the breaker close and open. “Ba-dump-bump!” The radio crackles. It’s correct.
It’s time for a run to check vibration, etc. Another quick radio conversation and I and the client’s electrical engineer tell them that we’re ready at our end. We hear the breaker close and watch the current jump up and settle down to a value we expected in a couple of seconds. “Good,� I think.
Wrong! The radio screams “Shut it down, shut down, shut it down!!!� I reach over, slap the big red emergency stop button and the breaker dutifully opens.
The radio sounds again. “It smells like a barbecue out here…� For my friends who may not be familiar with American barbecue, it usually involves cooking over a smokey WOOD fire.
I take the radio at my end. “Let me ask a silly question,� I say. “When you got this motor in, did you also get a pallet with a couple of wooden crates about a foot and a half square on it?�
Radio pops. “Yeah. We thought that was spare parts. They’re still at the warehouse.�
I replied, “Those are your bearings. This is a sleeve-bearing motor. It’s shipped with a wooden block supporting the shaft inside the bearing housing. That’s where the smoke comes from.�
The motor was torn down for inspection and the shaft was found to have warped from a few seconds of running 3600 RPM on oak blocks instead of the sleeve bearings and lubricating oil.
The moral of the story:Â Never assume that everybody knows their job as well as you know yours.
So NOBODY else had done this before? Interesting experience level for a crew handling what must have been some expensive equipment. At least it was probably oak, so it smelled decent.
back in the days when I was teaching management i tried to emphasize follow-up as a function of management as vital as planning and directing. And even though I knew better I was caught with my pants down around my knees more than once because I assumed it was done right and didn’t follow up to be sure..
Surprised there wasn’t a big sign on motor “No Bearings Do not Run !!!” I’d almost lay the blame 50/50 on that screw up. Something similar to no acid in battery don’t charge or no oil in new motor don’t run type of thing.