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need help to ID caps in my phase converter

jsdspif

Plastic
Joined
Sep 14, 2015
my phase converter took a dump and I'm trying to replace the caps in it but they don't have any sort of ratings.i don't actaully know if mine is home made or a company.I bought it used probably 20 years ago. Anyway there's 4 big oval dual capacitance ones that has the following writng on it
cedarberg ind. inc.
83rr5075100
235-8405-2

then I have 2 black caps that have the following
mallory
made in USA
CEDARBERG IND. INC
83RS75100
235-8430K-04

I have no other info on the converter .One thought i did have was to test their capacitance but with them being so old and also the fact I guess one or more have gone bad so I don't think I'd get accurate ratings as far as using those ratings to buy new ones. I thought someone may know where to find numbers. I saw a mallory product book from 1985 but those numbers look nothing like mine.I also have found plenty of caps that look the same but their numbers also don't match mine,and they're labeled with their ratings so I could order them if I knew the value of mine. If anyone could be of any help it would be greatly appreciated. Thanks
 
Cedarberg no longer offers much support for their rpc line, you might find those capacitors by doing a search with the available part numbers on them, if that does not work Cedarberg might be able to help, but they want $25 up front....... or maybe someone here can help with test procedure, which might require an actual cap tester.
https://cedarberg.com/troubleshooting/

Edit: This showed up for search of 235-8405-2
https://www.ebay.com/itm/276291617193?chn=ps

Not finding anything for 235-8430K-04
 
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You have two problems now. 1) Cedarburg sells replacements, but will not tell you anything about them. 2) Mallory got "eaten" by Cornell Dubilier (aka "CDE"), and the part numbers changed.

The 235 number is a Mallory number, but without an old catalog, you may not be able to cross it.
 
my phase converter took a dump and I'm trying to replace the caps in it but they don't have any sort of ratings.there's 4 big oval dual capacitance ones that has the following writng on it
83rr5075100
235-8405-2

then I have 2 black caps that have the following
mallory made in USA

83RS75100
235-8430K-04

What exactly does that mean., Took a dump? might have nothing to do with the caps?

Half the research has been done for you on the oil filled run caps ( oval) but doubt that's your issue. 25uf 660VAC 60Hz ebay ad given earlier.

The black round caps are likely the starting caps and a lot can be surmised by their physical size. Not starting, is that what taking a dump is?? A description, measurements, and a photo could help your cause a bit.

Here's a link to current part numbers for the run caps.you would need to confirm the physical size to fit your enclosure.

https://www.cde.com/site-search/results/?search=H64S6625A0AF&submit=

for the other start caps you could try Cedarburg, but that may not be the issue, we have no idea what that may be.
 
Quite true.

On the other hand, if the RPC is 20 years old in his use, it's likely that the start caps are "past their best by date", even if they are not the proximate cause of it not working. Replacing them is only avoiding further trouble, assuming he gets it working again, even if they are not yet completely shot.

Actual cause could be anything from the capacitors to a relay, a loose wire, or even the motor giving up the ghost. The motor is probably the toughest and most reliable part of it, though.
 
Anyway there's 4 big oval dual capacitance ones that has the following writng on it
cedarberg ind. inc.
83rr5075100
235-8405-2
Run capacitors. Measure the capacitance of all four. See what you get. Probably don't need replacing at all.
then I have 2 black caps that have the following
mallory
made in USA
CEDARBERG IND. INC
83RS75100
235-8430K-04
Start capacitors. Measure these as well. This is probably your problem. Just as well if one of them is a goner.
Replace the black ones with the equivalent capacitance in the metal can type. Never have a problem again.
What is the horsepower of the idler motor? That will tell what you need.
 
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this gives indication of part of the problem. It's actually my friends converter I called him last night to get more info as far as size. We use it sometimes on weekends to run a standard vari speed head bridgeport,sometimes a 6 x 12 surface grinder would be running,other times may be a clausing lathe. I think what he said was he was running the mill then the mill stopped and the phase converter made a ggggrrrrrr sound so he shut it off. This converter has a start and run switch. The burnt wires he said have been that way for over a year but it stayed working. I test the black ones at about 430 uf on my chinese tester and I have 2 testers and they both give me about 430.On the cap there is a 430k in the part number so maybe that's something? the oval ones I get about 6 uf on the fan terminals and about 40 uf on herm terminal (i think it says herm?) checking them though with my old radio shack tester i get about 5 uf and about 34 uf so there's some discrepency there,but even knowing that I still don't know the voltage rating. I have a source for these ovals (I think I didn't know the values when I was on the site) the black ones I don't remember seeing a value that high. I'm thinking the fried wiring is the problem and caps are possibly all good,but I'm all for replacing them even though they all measure the same ,so I think it's unlikely one is bad,but he got this used probably 20 years ago.It's in an unheated (or barely heated,like 35 in winter until he starts a fire) so my thought was just replace all of them,caps don't last forever and he's got to do whatever to replace the wiring but I need all the ratings. I'm guessing the converter is a 5 hp and it runs the 3 hp mill?
runcaps.JPGstartcap.JPG
 
Looking up what Mallory numbers I can in older catalogs (I unfortunately tossed the ones that would have them directly), three numbers of the middle section generally are indeed the capacitance (nominal or minimum) in uF

So the "8430K" is pretty likely to be 430uF, the "8" being something else.

I would not bother replacing the motor run (oval metal case) parts. They don't have the same sort of "wear-out mechanism" as the very highly stressed starting capacitors.

When the oval ones are bad, they will generally measure near zero capacitance, due to the opening of a "fuse" element inside. The numbers you get are quite typical of a good one, in the 5 uF range for a fan, and a larger section for the other motor.
 
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