SSTC Board - Spacing Requirements for High Voltage

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

Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>

I'm currently working on adding the TO-247 (IRFP460 etc...) FETs to the
design and am having difficulty fitting it in.

Anyways, assuming maximum voltage of 240VAC * 1.414 = about 339 volts worst
case, what would be a minimum spacing for traces on FR-4???
I typically never worry about this since all high voltage boards I design
have AMPLE spacing between traces.
Right now, maximum spacing for this package in its current position is about
0.050 inches.  Not too much.   I may not be able to put the TO-247 pads in
place, so you may have to resort
to manually soldering the packages on the existing miniBLOC pads which
shouldn't be much of a problem.

Anyone have a guide for board spacing vs. voltage and material???

Thanks

Dan