Dry Cell ??

[rcdallas]

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[wtdoor67]

You need to advise that lady to find a good electrician of her choice, to come out and check out that lash up. Sounds like a scam alright. That voltage reading is about the bottom range of a lot of 120 volt equipment.

Look it over and see if it has a label naming the manufacturer. Course it's probably too late to catch up with the installers of that contraption, but it would probably make her appliances work better.

[loodvig]

That thing looks like an old 'dry pot' like they used in the old 550 volt delta factories. They would use it to get a lighting leg off it. Now you'd have one leg of delta going to ground and the trouble would start when another dry pot would be put in and they would use a different leg of the delta! You'd throw in one fuse and throw in the next and the first one would blow!

[Bear]

Looks like a buck transformer designed to drop the voltage as you describe. Means that most things will operate at lower current (and lower power.) They're not a great idea, although they can be useful for lighting applications to extend lamp life.

These things are widely sold for whole-building power reduction. They cause major issues with high inductive loads like elevators and compressors. The trouble is that they are being sold by professional salesmen who don't give a damn about anything other than getting their commission.

A version of these things is used within the power distribution industry for nudging up voltage on long rural runs. Same effect as changing up to a higher voltage tap on a transformer.

I would guess that the copper and iron losses on the transformers pictured would have negated any savings. Remove them if the mains incoming voltage is normal.

[Bear]

Oh, and one other thing. A dry cell is a battery. This is just an open wound transformer. Theoretically on a three phase supply they would have three separate transformers, but I see they've used one for two phases and one for the remaining single phase with what looks like the two high current secondary windings in series. If that really is a 120 degree apart three phase system then two phases wound on a common core is odd. Secondly if the single phase transformer has the secondaries in series then it will be creating a voltage imbalance since the voltage drop will be double the other units.

The voltage drop is determined by the ratio of the primary winding turns to the secondary winding turns.