67Dart273 said

In my early years starting out in refrigeration / HVAC, my boss (we were a small outfit of only 4 guys) did some service work on the mining chillers down here in "The Silver Valley." A couple of these were 250 HP Dunham - Bush shaft drive. Because these were so deep in the mine, they operated off 2300!!!!! V 3ph. (NOT 230!! 2300!!). In mines this deep, they get HOT. and HUMID. (I'm told) water falls right out of the air, off the ceiling and rocks, and in some places you are STANDING in water. Imagine servicing something like that. Dark, hot, humid, ...................

Anyhow, the mine (millrights? minerights?) occasionally had to move the chiller, and "stuff happened." They could not get one to operate, so of course you do what ANY good on site electrician does..........you start bypassing safeties!!!

There are all kinds of them.......over / under temp, over / under pressure, water flow, and PHASE DETECTORS. These monitor the 3 ph power coming in.

So "we" (they) fire it up and what? It's rotating BACKWARDS. This is not the "best thing" for a compressor that costs over 20K (dollars in the eighties) to overhaul!!!




Not personally, but a reminder to others...........................

(you can easily "rig" your own hydrotest, it only takes .............water)

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