ScottyUK 17 Nov 18 12:05
Yes, not new to me. It was the reaction from my wife that was entertaining.
I did, as mentioned, schlieren measurements on breakers, using high-speed photography, to study the gas flow pattern in the quenching chambers at ASEA, now ABB. That made me aware of the risks involved in high-power breaking. Especially under fault conditions with DC components in inductive circuits. I found electronics a lot safer and kind of switched career from that moment on.
But I was still supposed to be a power electric guy and was sent to handle quite a few dubious installations. One of them was a case where Siemens breakers (with Expansin
TM) in them.
I asked the personell about maintenance and especially if the Expansin had ever been checked?
"We ordered some, many years ago, but we seem to have lost it" he replied. We couldn't see a trace of the Expansin in the breakers, so I called Siemens and asked what to do. "You can use ordinary water" was the answer. Just water? Yes, and if it is out-doors or cold in the room, just add some of that stuff you use in your car. Ordinary Anti-freeze? Yes, you can buy it at any gas station.
I got papers signed and we got that flourescent liquid at the nearest gas station. It was an A + B system, so we isolated one part and put the "moon-shine" Expansin in all the breaker poles. Then isolated the other system and did the same thing.
We even tested the thing. "Better to fail now than failing with no Expansin in them" was the reasoning. There were trip solenoids. So we didn't have to stand in front of the breakers. It worked!
I called that guy at Siemens and his reaction was "You did? And you are OK?". I said yes. To which he answered: Hell isn't as hot as the clerks are shouting about.
Gunnar Englund
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Half full - Half empty? I don't mind. It's what in it that counts.