capacitor replacement - PhasePerfect converters

[David Zaret]

aaron thanks for the education - this is great. i think for right now, given that i'm having issues, i'll buy a set from PP and get back up and running. then moving forward, i'll source the caps. the one you posted looks great, and mouser has a panasonic one that is backordered until august that also looks viable. next year i'll go that way. thanks.

-- dz

[Brice Rogers]

An electrolytic capacitor is a "polarized capacitor whose anode or positive plate is made of a metal that forms an insulating oxide layer through anodization." Polarized means they work with DC (direct current). AC (motor) capacitors are not polarized. They work with...well...AC (alternating current). It is not uncommon that AC (non-polarized) caps are oil filled. Probably to help dissipate heat and also act as an internal insulator. Many/most oils are flammable. So, contrary to what Aaron mentioned, the AC capacitors are not electrolytic. On old electrolytic capacitors (DC) that have been sitting for many years, some people slowly apply voltage to "re-form" them. That apparently re-establishes the oxide layer inside. But on an AC (motor) capacitor that isn't necessary IMHO. (BTW, I'm a degreed EE).

I don't think that a (new - old stock) 10 year old oil-filled AC capacitor is going to be a problem as long as it has been stored under normal conditions (ie. not in the Sahara desert).

30-40 years ago AC capacitors used to seem to last nearly forever. But most of the current caps come from China and seem to have much shorter life spans. About every 5 years or so I need to replace the AC capacitors on my whole house air conditioner and on my swimming pool pump. Often when they fail they will bulge on the ends. That is a great clue that it has failed. Last week I replaced my pool pump capacitor. I bought one locally and bought a spare on ebay (for about 1/2 price).

So, buy the surplus caps and you'll probably not have any problems. Also buy a set of spares. Change to connectors on your phase converter so that you can just drop in the new caps and quickly connect it.

[David Zaret]

brice, thanks for the education - this thread has been very informative. i'm worried about the age of those surplus caps. i think that when the time comes, i'll spend a bit more for "newer" caps, and modify the wires as you suggested. Mouser sells panasonic caps of the same/better specs and size, and they are still certainly affordable enough to not be a consideration.

--- dz

[jim mills]

I was told by the PP people that the unit can be damaged if a cap goes out during use. I replaced mine at the 9 year mark. They told me most units sent in for repair after the 10 year mark are due to failed cap's. The repair can be in the $1,000's.

[David Zaret]

I was told by the PP people that the unit can be damaged if a cap goes out during use. I replaced mine at the 9 year mark. They told me most units sent in for repair after the 10 year mark are due to failed cap's. The repair can be in the $1,000's.

yep, i got the same info. i run my PP every day, sometimes 8+ hours a day... so my intent is to replace them yearly. just trying to come up with a more affordable approach, given that the caps are "standard."