In a message dated 2005-12-17 07:19:01 PM Eastern Standard Time, 
[EMAIL PROTECTED] writes:


> More like a wiring error IMHO, I have had a similar problem in Au where 
> an electrician did not realise what 208V equipment was :( Drew a hell of 
> a lot of current for a few reasons ;)

I'd concur wholeheartedly after thinking it over for a bit. Key is the 
difference between a wye vs delta connection.

> 
> 
> > As to the voltage conversion, be careful how you're measuring things. I 
> may 
> > have this backwards, but I believe 208V normally refers to a delta 
> connection, 
> > whereas 240V refers to a wye connection. Picture the voltages of each 
> phase as 
> > an equilateral triangle centered at and spinning about the origin. The 
> sides 
> > of the triangle are 208V long, and each of the corners is 120V from the 
> > origin, which represents the neutral. Thus if you measure one phase of a 
> delta 
> > connection (where you're measuring between two of the phase wires) you see 
> 208V, 
> > vs. measuring from a phase to the neutral where you see 120V. I lost a 
> factor of 
> > two somewhere in the visualization, but the basic concept is correct. Is 
> it 
> > possible that you've somehow crossed up the motor connections such that 
> it's 
> > expecting a delta connection but you've supplied a wye connection? That 
> too 
> > would account for a very heavy current.
> 
> There is a mathematical formula for this, but stuffed if I can remember 
> this (besides it is 0815 on a Sundry morning and I have not had the 
> wakeup levels of caffeine or nicotine yet)
> 

Simple ratio of sqrt(3) / 2 between the 208V and the 240V.

Steve Hendrix
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