69,000V voltage regulator from Idaho

A mostly intact voltage regulator from Allis Chalmers, still humming at 69,000V. Here's the nameplate:

I do wonder if Idaho Power has any other equipment from Allis in operation, since they tend to use the old transformers until they die or upgrades are made. The only modifications that have been made to this one appear to be the new polymer bushings.

The 69kv regulator station transformer is probably fairly young... late '70's probably.

THIS is the kind of equipment that constituted the 'meat' of Allis Chalmers.  We saw tractors, which was 'bread and butter'...  our tractors were consumer-level products, the greater substance was in providing for industry.

The line regulator is a gadget of simple elegance-  it's an autotransformer, with taps on it's buck-boost coil... that makes it variable.  I've never worked with one, but I've been around a few in substations... Sometimes they're manually adjusted, sometimes they've got telemetry and gearmotor to switch taps remotely, and sometimes they're kinda automatic... but probably just within a limited range.

Power comes in to a Y winding, which acts on the output winding, and is either pulled down (bucked) or pushed up (boosted) in voltage by a third winding that's fed through an array of taps.  the lower the tap setting, the higher the boost or buck current.  By reversing the phasing of the third winding, it bucks, or boosts.

This thing is rewindable basically forever-  the parts that do the hard work are the core (probably laminated silicon steel) and copper windings... the parts that take the greatest abuse are the insulators (oil inside, ceramic everywhere)... and they're all replaceable... so unless it's really, really damaged, it'll never become 'worn out'.  Furthermore, because of physics, the technology of this process really can't be beat by any other form of technology... it's too simple, has practically no dependancies, and is invulnerable to basically anything but direct physical impact from a very large, heavy object.  In short, whatever they'd replace it with... is exactly the same thing.

Call Steiner or Sandy Lake, tell them you're doing a transmission rebuild, and need an Allis type AFR 21-112-281-073 regulator... mebbie they'd have one in stock?