>Tom gets the troubleshooting prize for this problem.
// Agreed
>After pulling the caps,
>I checked the equalizing/bleeder resistors and found one open! It looks
>absolutely perfect, no signs of physical damage such as heat, cracks or
>scrapes. I'll need to get a replacement, then see if the cap is damaged
>beyond use. It's doubtful at best.
>
>Thanks again for all the feedback. It's been an education beyond the initial
>problem.
>
// Unreliability is why we do not proffer wire-wound resistors for
electrolytic capacitor equalizer/bleeder service. Although lower value
wire-wound resistors are fairly reliable, as you have apparently
discovered, such is not the case with higher-value units.
- My guess is that the capacitor that had the open bleeder has white
deposits around the pressure vent. and/or shows higher leakage @450v.
Replacing the entire string of capacitors with new, 105ºC units might be
best. I would also replace the wire-wound equalizer resistors with MOF
resistors because they are more stable & more reliable. /sources:
Mouser Electronics -- 800.346.6873. Digikey -- 800.344.4539/
cheers, Mark
- R. L. Measures, 805.386.3734, AG6K, www.vcnet.com/measures.
end
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