Got a call about tripping breaker in our glass production studio. Went over to check it out and found among other things a small 208 to 240V buck/boost transformer, single phase, feeding this old guy. Step up 230 to 20,000V.

Hmmmm. Anybody ran into one of these before? If I take the buck-boost out of the feeder what would you protect the primary side with?

You reckon it contains PCB's?

I know what it is used for, do any of you? I gave you a small hint already.

A few decades ago my dad responded to a service call at a motel. Mysterious burn holes had appeared in the soffit overhangs overnight. He found neon lighting transformers in the attic, with the primary leads cut long and the secondary leads also cut, laying near the holes in the soffits. He figured lightning caused a voltage rise on the primary leads, and then stepped up to an extremely high voltage at the cut end of the secondary conductors.

Perhaps this is a transformer from the neon-lighting days?

We have a winner!

This particular transformer is for bombarding the freshly built tubes prior to adding the neon or argon and mercury. They pull a vacuum on the tube and use the transformer to draw an arc through the tube to burn out any impurities.

I learned the breaker tripping issue was simply due to trying to bombard too long of a tube and drawing too much current to sustain the arc and get the temp up to where they wanted. I told them to buy a bigger transformer and we'd upside the feeder.