>
>Hi All,
>
>Having a problem at my shop with a 100kw induction furnace. The furnace heats
>a billet for drop forging. The problem is when you start the funace at about
>50% the GFI in the switch gear trips. If started at a lower percent it's
>fine.
>But that is not good enough. The unit operates at 480v 3phase 2000 amps input
>to the power supply. The output is 1200 vdc 1980 amps at 1000hz. The input is
>fed to the rectifier board which are SCR's. Then to a reactor on both
>positive
>and negative. then to a inverter. The GFI tripping is a inducation of a
>unbalanced load, according to one individual. My thought was a step start on
>primary of the power supply. The capacitors that shunt the SCR's and the
>SCR's
>themselves look like a short for a instant. There is one thing I noticed on
>the schematic that I thought was not rite, they have the SCR's shunted with a
>resistor and capacitor in series. Shouldn't they be in parallel.
R and C in series is correct.
>The reason
>for my asking for help is that everything you think you would like to try
>cost
>50k. Everything is water cooled, resistors, capacitors even the conductors in
>the unit. So, anybody out there with any experience in this area out there?
>
>Thanks for the help!
>
>73, Mike
>KF8OD
>
>Long live QRO!
>
>--
>FAQ on WWW: http://www.contesting.com/ampfaq.html
>Submissions: amps@contesting.com
>Administrative requests: amps-REQUEST@contesting.com
>Problems: owner-amps@contesting.com
>Search: http://www.contesting.com/km9p/search.htm
>
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
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