- Two sets of two 270uF, 420V(max) caps connected in parallel.
- Those two sets are connected in series
- In effect, I have 270uF rated for 840V
- Using the following formula:

- and with the values:
- n = 2
- Vrated = 420V
- Vbus = 497V
- Imax_D_leak = 3 x sqrt(270uF x 420V) = ~0.001A (assumes no leakage in one set and maximum leakage in the other)

- I get an Rbalance of 343K

IMHO, the nearest common value for optimal balance resistors would be 1/2W, 330K ohm. Unless I calculated wrong, or am missing something?