Problems with dual Athlons (power; popping breakers)

Alan Ward award at
Wed Jul 31 23:54:27 PDT 2002

Michael Stein ha escrit:
> <snip>
> One possiblity I've thought of but haven't tried would be to switch the
> PC power supplies to the 240 setting and run them off of 208 (between
> two phases of the three phases).
> </snip> 

Basically, you're talking about a delta connection versus a more 
normal Y connection. There's a lot of litterature on the problem
of levelling the load of each phase on 3-phase transformers (that 
last stage of mid-to-low voltage eg. 3500V to 110V or in 
Europe 20000V to 240V). 

If you do switch to delta, you *cannot* earth the equipment - the
earth wire just keeps leaking current and your differential breaker
goes off.

Be aware the 240V setting is usually rated at 240V +- 5%, or 
maybe 10%. That is: it will work at old French 230V level. It will
also work at British 250V. But it may not work well at 208V.
At the very least keep the wires large bore and short.

Your major problem will be frequency. 240V is delivered at 50 Hz - 
not 60Hz.

Luck - and keep an extinguisher handy!
Alan Ward

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