If I had a variac I would use it, better safe than sorry and it can't hurt anything.
Stanwal (System | Reviews | Threads | Answers | This Thread)
A cheap way to do it is to power it on for only a moment. Say less than a second. That will allow some A/C juice to get in and start forming the caps, but not enough to make them 'pop' if in bad form.
Them, after maybe ten minutes, repeat and leave on for say two seconds. Same thing wait for about ten minutes, then turn it on. It should be fine with this preconditioning.
Elizabeth (Threads | Answers | This Thread)