Things You See at Work

[ILexpatriot]

In the '70's I worked for a company in Houston called Maintenace and Service. I rebuilt electric motors, A/C and D/C. I rebuilt motors they brought in on and 18 wheeler lowboy. We unloaded it with a dual 40 ton overhead crane. Most running 30,000 volts.

This is an OLD pump station along the IL river. 1910 iirc. There was the big 450hp motor and a smaller 225?. Theyve been underwater many times aver the years from flooding, and the big 450 finally had to have the coils rewound. A few years ago, a snake was laying in it when they turned it on and the bones and blood compromised the insulation. I went down to try to patch it up because water was high, and rain was coming..
Pressing the start button on a 100+ y/o, 2200v motor, with compromised insulation, when the start button is 15' from the motor was "exciting". They didn't put much thought into egress back when they built these things.
We were the only company anywhere around that would work on them. And no one taught me anything about them besides what our institutional knowledge was, and what the operator knew.
Somewhere back about 1980, iirc Cutler Hammer took the original MCC apart and Frankensteined a bunch of original parts into a new cabinet with a modern disconnect. But documentation and schematics were scarce.
It was a fun learning experience, but probably useless anywhere else except for maybe working at a generating station since they work a lot like a big older generator. The field is A/C, but the excitation is all variable DC.

 

[ILexpatriot]

The black thing on the left is the 3p knife switch that shuts off the 2200v feeding the 3 pots on the wall. They were separate, so you had to pull each knife out one at a time with a hot stick, inside the building. I'm sure that would be fun in a meltdown.. All the conductors were exposed. And since it was across the line starting, the 2200v was fused HEAVY at the pole that's right outside. I can't imagine the available arc flash current. Gotta be in the millions of amps.

 

[ILexpatriot]