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Soldered 3 capacitators to my motor. Seemed fine before I did that but how do I know they werent damaged in the process? How do I know they're doing what they're supposed to be doing?

First you need to confirm they're soldered on firmly. I'd say most issues with motor capacitors would be flaky solder jobs.

If you can say for sure they're soldered on, you can take a close look at the tops of the capacitors. They're designed to expand outward if they blow. If the top of a capacitor is raised or you see any kind of discoloration (usually brown) emerging from that area, the capacitor was blown. You might also take a sniff and see if you can smell a burnt smell.

I use the same method to see if capacitors on a computer motherboard have blown out.

The solder-joints are fine but there is some discoloration around the legs on at least one of them (had to extend them as they were only a few millimeters long). Haven't noticed any smell yet.

You said that you "extended" the capacitor leads. I think that the best way to have a troublefree straight forward install is to get caps with correct length leads. Every joint is a potential trouble spot later on after everything has been jolted, moved around during use. If the soldering is borderline, you will have problems. Save youself future headaches. The finished joint should appear shiny and rounded like a bead. If the joint looks gray or dull, it will come back to bite you at the worst time, called a cold solder joint. There are many soldering videos on utube that will help quide you to a solid clean install.

Coelacanth wrote:First you need to confirm they're soldered on firmly. I'd say most issues with motor capacitors would be flaky solder jobs.

If you can say for sure they're soldered on, you can take a close look at the tops of the capacitors. They're designed to expand outward if they blow. If the top of a capacitor is raised or you see any kind of discoloration (usually brown) emerging from that area, the capacitor was blown. You might also take a sniff and see if you can smell a burnt smell.

I use the same method to see if capacitors on a computer motherboard have blown out.

Tell me about it. Back around 2005 Dell among other manufacturers computers were sold with bad caps and it was a huge debacle. I remember having to replace many motherboards as a result.

http://en.wikipedia.org/wiki/Capacitor_plague

ESR tester (equivalent series resistance), test capacitors in cct.
Something like this http://midwestdevices.com/ (not vouching for that company, just showing what an ESR tester is)

This seemed like a good topic to bump up with a new post. I've never seen disc capacitors soldered across the + + and the - - terminals before. I don't see how that would do anything, unless a change builds up there.
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Trinity (and others) used electrolytic caps for the +/- and ceramic for the grounds. Not sure why they went that route but it was pretty common in the earlier days to see them.

Frankentruck wrote: ↑Mon Feb 10, 2025 5:42 pm This seemed like a good topic to bump up with a new post. I've never seen disc capacitors soldered across the + + and the - - terminals before. I don't see how that would do anything, unless a change builds up there.
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Those ceramic caps are doing nothing, Possible the solderer misunderstood the directions.

But this is weird.

RogueIV wrote: ↑Mon Feb 10, 2025 7:47 pm

Frankentruck wrote: ↑Mon Feb 10, 2025 5:42 pm This seemed like a good topic to bump up with a new post. I've never seen disc capacitors soldered across the + + and the - - terminals before. I don't see how that would do anything, unless a change builds up there.
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1000014308.jpg
1000014307.jpg

Those ceramic caps are doing nothing, Possible the solderer misunderstood the directions.

That was my thoughts too, but wanted to see if I was missing something.

Yeah they are doing nothing.

They should be from each brush hood to the motor can or motor tab(if a modified).

Electrolytic is also fine but a ceramic cap would be sufficient. If you haven't sat there and cooked the cap it should be fine, they are pretty tough. I've discolored the end of the potting a time or two at the leads.

This motor is just going into my Parma collection, so the caps are all coming off. I just was puzzled by how the little brown turds had been installed.

GoMachV wrote: ↑Mon Feb 10, 2025 6:29 pm Trinity (and others) used electrolytic caps for the +/- and ceramic for the grounds. Not sure why they went that route but it was pretty common in the earlier days to see them.

You can't use an reversing esc with the electrolytic caps.

Frankentruck wrote: ↑Mon Feb 10, 2025 8:31 pm I just was puzzled by how the little brown turds had been installed.

The installer was also puzzled. The leads are shorted by the endbell. On the plus side, if you need some, those should be fairly fresh as they have never seen electricity...