You would think that a contracting company, the apprenticeship trained electricians that installed it, or the maintenance electricians who worked with it for more than seven years, would have raised an eyebrow at a 480V MCC in a change room that included; lockers, a toilet, a shower, a hot water heater, and an overhead bus duct.
Yes in the same refinery that I wrote about earlier (see Waist Water Treatment...), on a weekend, emergency maintenance callout to a boiler unit in the refinery, I was directed to the change room to lock out the equipment I needed to work on. I was a bit confused when the unit operators said “change room” but I followed the directions to the room and when I opened the only door into that space I couldn’t have been more surprised. The room was about 8 feet wide and about 30 feet from the door to the back wall. Within 3 feet of the door on the left began a row of lockers about 10 feet long and on the right an MCC of about equal length, with a bench running the length of the lockers down the center. Dividing the back wall into equal portions was a shower on the right and a toilet on the left. Half way between the toilet and the MCC was a hot water heater, (I can’t remember if it was gas or electric). And the MCC was fed from a transformer out side, just behind the back wall, and connected by a bus duct run along the center ceiling, straight over the shower. Honest I’m not making this up, it really did happen.
I did the work necessary to correct the maintenance problem and went home. When we held the next weekly safety meeting, during the open forum section, I announced that I had found “a crapper in an MCC or an MCC in the crapper”. Everyone in the department was chuckling until I explained what I was talking about. Then I could see there looks slowly change to astonishment. The MCC was in that change room for almost seven years, and many of them had worked on that MCC without any notice or comment of the unsafe condition.
Without going into detail I will tell you that the room remained unchanged for almost 2 years after I first made the company aware of that safety concern. It was one of the first projects designed by a recently employed electrical engineer who was a native of India. (As he had implied, things like this were normal in his native land.) It was when the operators said they could smell smoke, “like something electrical burning” that the company took action. They moved the operators change room into a portable trailer and removed the plumbing from the room turning it into what they thought was a full fledged electrical room. Then someone else (not me I had been in the spot light for too long already) said that it needed a second door to meet NEC Code. They soon added the door at about where the old water heater was and completed the transformation.
The equipment connected to the MCC was the TTR’s that boost 480v to rectified 50KV to supply plates in a smoke stack precipitator. (Stack precipitators are used to remove solid particles from the hot gasses) And there is a whole other story about that, stay tuned.