[ARC5] Back to basics: Capacitor breakdown voltages

[Jim Falls]

OK, I can calculate series/parallel combos, but how does the breakdown voltage work? 

My BC -375 has a leaky trio of 1uF oil filled bypass caps that have 3kV ratings. Mouser has pricey ($20) 1uF and .47uF units rated at 2kV. How does that breakdown work?

One shorted, and the plate current meter went up like a sparkler. Other 2 are making my PSU lug down, B+ dropping to 900 from the usual 1100 VDC it idles at. I get 800 while transmitting instead of 1kV like it usually does. 

Cheers!
Jim K6FWT