Re: Dead MMC. was: AAAA! My coil...

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

Hi Terry,

I'm not as confident that running a 12kV cap bank at 12kVp is a good idea. 
Sure, manufacturers derate their caps, but they always have. Regardless, 
the user should still design in their own derating (MMC or not), especially 
in TC service. I think if we all ran on the edge like this, we would be 
seeing a high rate of failure.

Take care,
Bart


Tesla list wrote:

>Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
>At 9000 VAC, the peak voltage is 12728 volts.  Six caps are rated at 12000 
>volts.  So you are a little over.  However, I would not worry about it at 
>all.  Six caps per string should be fine.  If you are using 10M resistors, 
>they are at their power rating (0.45 watts) so no problem there 
>either.  However, the resistors may get a little warm but spacing them 
>should keep them from heating the caps.  If you wanted to be real safe, 
>you could use two resistors in series per cap.
>
>Cheers,
>
>         Terry