above: 350v 3300uF electrolytics

I just received a capacitor bank from a scrapped Chloride 100kVA+ online UPS
system. It consists of 48 350v 3300uF large can electrolytics made by
Itelcond of Italy. I have tried to get specs on them from Itelcond and they
have demonstrated that they are a valueless company. I will celebrate their
fall from the market.

Since these caps are from an inverter and are not of the photoflash variety
they were not meant for short circuit torture as energy discharge film/foil
caps are. They appear to be made in 1988 and should probably be tested and
reformed before they get used for anything.


Above: testing and reforming each cap

Electrolyic caps age duing storage and it is a good idea to "reform" them
after such storage. The only consumer item I have ever seen that suggest you
worry about this are camera flashes. They tend to suggest you let them
charge up fully after periods of unuse before using them again. Reforming
just consists of charging a cap to it's rated voltage or a bit more with
limited current and letting it sit there for a while. For fun, I chose a
reforming voltage of 360 volts for a period of 10 minutes per cap. My power
supply consisted of a variac, transformer pulled from a Uniphase lab style
HeNe laser and two 400 volt 3A diodes in series. The current available was
inherently limited and it took a few minutes for each cap to even reach 360
volts. The variac had to be set to just under 30% of the 120v setting to
reach this.

A quarter shrinker or can crusher might be fun final applications
02-18-2000 02-19-2000