Buck & boost transformer

[Ilianh]

I stumbled upon a 1.5KVA transfo, primary is 240/480V and secondary is 29/48V.


Its an outdoor transformer, with the whole thing being stuck into some kind of sand concrete and in a metal box....

Anyone knows what are those used normaly.. And any ideas on what interesting projects it could be used?

Thanks.

[Da5id4Vz]

I had the misfortune of building computer rooms and recording studios in a building that required these things.

The building was fed with an archaic 3 phase power format referred to as "high leg". It was a three-phase Y primary with two legs measuring 208VAC to ground and the third leg measuring 240 to ground.

The buildings 40+ HVAC units ran just fine on this stuff. Wherever I needed to run a big isolation transformer or UPS is where the bucking transformers came in.

At the primary side to the isolation transformer, one or these things would be attached to the high leg. The output was attached out of phase back on to the leg causing it to drop down to, about 208 volts.

When it was time for the local utility to upgrade the transformers to our building, it was heartbreaking that I couldn’t coordinate a transfer to a regular three-phase service. Those things were tremendously inefficient.

I did find myself with a bunch of extras at one point. Too small for boat anchors and too heavy for doorstops, they went to the landfill.

Perhaps you can find a better use than I did.