240V -> 208V -- How to?

I am seriously looking at a Miele front load washer.
It uses 208V and you have to buy a $200+ "adaptor" in
order to use it where only 1ph 240V is available.
I have done a good bit of 1ph 240V wiring and still remember
some stuff from my college physics classes.
How would one put such an "adaptor" together that would be
robust, safe, and cheaper than $200 ?
Figure the current would be 30A (to allow using a Miele dryer
at some future date.
Jeff Dantzler
Reply to
Jeff Dantzler
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You need a buck boost transformer. A new one will set you back $100-$150. mcmaster.com has them. You can also find used or surplus ones on ebay for less. Are you absolutely sure you want a Miele? According to Consumer Reports, their reliability is less than stellar.
Reply to
"AL" wrote: You need a buck boost transformer. A new one will set you back $100-$150. (clip) ^^^^^^^^^^^^^^^ Maybe you could find a 32 volt transformer with sufficient current rating, and hook the secondary up to buck line voltage.
Reply to
Leo Lichtman
The "adapter" might be a capacitive phase converter as 3-phase power is usually 208 per leg.
AL wrote:
Reply to
Tim Killian
Buck/boost transformer, wired to buck the incoming voltage.
Check in mcmaster carr, they sell them there.
Reply to
jim rozen
Yes, it might be a static phase converter. Germans have 3 phase power in their homes (or so I've heard) so the Miele might use 3 phase power. Or it could just use 2 of the 3 phases.
I really have to wonder why someone would spend all that money for a washer and then have to either use a phase converter or a buck boost transformer. Why not just get a front loader specifically designed for 120V?
Reply to
Nice idea, but no.
When you hook a transformer up as Buck-Boost you have full primary line voltage to ground on the secondary windings, so the transformer you use has to be designed for it. A lot of the surplus transformers you find are rated B-B, but the nameplate has to be readable, and you have to dig out the spec sheets and check first.
The cheaper filament transformers that aren't rated for B-B service will not have the proper insulation on the secondary windings for that use, and much excitement can happen - think "Fourth Of July Finale".
It might happen the first time you plug it in, or it can wait till after a few switching transients puncture the insulation. And best of all it can easily turn into a fire, if you aren't standing there with a fire extinguisher close at hand...
Reply to
Bruce L. Bergman
Yes, not all have 3 phase power in Europe but some do ( I too) , and then we have 400 Volt between the phase and not 240.
With 1 phase we have 240 V, that's in most houses.
Reply to
According to Bruce L. Bergman :
Well ... filament transformers -- especially those which can handle sufficient current -- are often designed for use with high power transmitting tubes, which often work with the filament of the tube at a rather high DC voltage.
However 32V is more likely to be a power supply transformer, not a filament transformer, which I agree may well not have sufficient isolation to allow the intended application.
Enjoy, DoN.
Reply to
DoN. Nichols
Actually, the filament transformers are likely the best ones for voltage insulation. Many of them are used in 400 to 600v power supplies. The 5V winding is specifically that high for just that.
I'm buying three buck/boost transformers to ease back my output from the 220 Wye to Delta.
But I'm buying real buck/boost units.
Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder
Bruce L. Bergman wrote:
Reply to
Martin H. Eastburn

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