- Capacitor again :- ( - 13 Updates
| "Dallas" <Cybnorm@spam_me_not.Hotmail.Com>: May 05 04:58PM I posted a data sheet for a KEMET motor run (20 µF +/-5% 450V capacitor 25 x 56.5mm and 450v) that would fit inside my rolling shutters tubular motor. Then I noticed that other data sheets described it as 45x78mm too large to fit. Turns out, the little capacitor is "obsolete" replaced by the bigger one. Exact same part number. (Brilliant KEMET) :- ( I have looked at these data sheets for 20 µF motor run capacitors: KEMET Panasonic Cornell Dubilier EPCOS/TDK Dayton Granger No luck. Capacitors have increased in size and I can't find smaller ones. I think voltages are higher and that requires a bigger can? Ducati Energia has one that is perfect... but natually none in stock in the USA or anywhere else I can find. (Like trying to finding a rainbow unicorn.) So my question is, does anyone know of a capacitor manufacturer that makes weird/non standard sizes/hard to find capacitors? ................................ What I'm looking for: I'm replacing a motor run capacitor 20 µF +/-5% 320 volts. Original can dimensions 35x77mm. (Not including the terminals) The max diameter I can have is 1.46" or 37.16 mm The max length I have is 3.8" or 99mm. -- Dallas |
| Ken <Ken@invalid.com>: May 05 03:01PM -0500 Dallas wrote: > can dimensions 35x77mm. (Not including the terminals) > The max diameter I can have is 1.46" or 37.16 mm > The max length I have is 3.8" or 99mm. Have you looked at paralleling two 10 µF caps??? You just might be able to find total dimensions that fit. Not saying you will, but worth looking at. |
| John-Del <ohger1s@gmail.com>: May 05 01:24PM -0700 On Sunday, May 5, 2019 at 12:58:56 PM UTC-4, Dallas wrote: > The max length I have is 3.8" or 99mm. > -- > Dallas Can you externalize the capacitor? |
| Look165 <look165@numericable.fr>: May 05 11:08PM +0200 Regardless to the voltage, since it is greater than or equal 450V, choose 22µF or 27µF which is more common. It can be easily found on Radiospares or Farnell. The size should fit. Dallas a écrit le 05/05/2019 à 18:58 : |
| tabbypurr@gmail.com: May 05 03:22PM -0700 On Sunday, 5 May 2019 21:25:01 UTC+1, John-Del wrote: > > The max diameter I can have is 1.46" or 37.16 mm > > The max length I have is 3.8" or 99mm. > Can you externalize the capacitor? probably the only option left. Another core needed for the lead. I assume the OP has looked on ebay for used caps. NT |
| Fox's Mercantile <jdangus@att.net>: May 05 05:58PM -0500 On 5/5/19 11:58 AM, Dallas wrote: > Capacitors have increased in size and I can't find smaller > ones. I had a similar problem. The replacement would not fit in the stamped steel "dog house." So the replacement was held in place with a piece of sheet metal cut to size. -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com |
| "Dallas" <Cybnorm@spam_me_not.Hotmail.Com>: May 06 04:17AM Can I toss in a general question? Is a motor run capacitor always described as a "motor run". This is the Ducati motor capacitors catalog. On page 15 they have their Metallized polypropylenefilm capacitors in metallic case... but they don't say "motor run" anywhere. http://www.farnell.com/datasheets/24524.pdf On page 23 they start their Single phase motor starting electrolytic capacitors. So they specifically call them "motor starting" Am I wrong to assume that those caps starting on page 15 are motor run even though they don't specifically say motor run? -- Dallas |
| "Dallas" <Cybnorm@spam_me_not.Hotmail.Com>: May 06 04:26AM Look165 wrote: > Regardless to the voltage, since it is greater than or equal 450V, > choose 22µF or 27µF which is more common. Really? I can pick a different µF? My limited research said that a different µF would cause over heating of the coils and shorten the life of the motor. I started with Farnell, no joy. Radiospares has an amazing filter system! If I sort by 20µF and motor start I get 5 hits all of which are too wide for the tube. -- Dallas |
| "Dallas" <Cybnorm@spam_me_not.Hotmail.Com>: May 06 04:27AM Ken wrote: > Have you looked at paralleling two 10 µF caps??? Wow, didn't know you could do that. :- / Interesting. -- Dallas |
| "Dallas" <Cybnorm@spam_me_not.Hotmail.Com>: May 06 04:27AM Ken wrote: -- Dallas |
| "Dallas" <Cybnorm@spam_me_not.Hotmail.Com>: May 06 04:55AM John-Del wrote: > Can you externalize the capacitor? I had that bright idea a couple of days ago... After an hour of staring at it, the wires run through the 2 limits switches on the way to the motor. When they reach the limit switch they click open. I pondered drilling holes in the end cap of the limit switch assembly but I just don't have enough room to get wires through. https://bicpentameter.smugmug.com/Other/Misc/n-Cv46BV/i-ZtPwDZR/A https://bicpentameter.smugmug.com/Other/Misc/n-Cv46BV/i-MDJpcpT/A The good news is that equivalent replacement motors are available. The bad news is that 2 of them will cost me $600 bucks. No es bueno. -- Dallas |
| Clifford Heath <no.spam@please.net>: May 06 04:45PM +1000 On 6/5/19 2:26 pm, Dallas wrote: > Really? I can pick a different µF? My limited research said that a > different µF would cause over heating of the coils and shorten the > life of the motor. Stay within 40% and it should be fine. Your blind motors don't operate for long at a time. The run cap effectively creates a third phase, and increasing or reducing the value moves that phase forward or back a little, but the tolerance is never tight on these anyhow. "start" capacitors should get switched out of circuit once the motor is spinning. They aren't needed and might not be rated for continuous usage. But it sounds like you need a run capacitor, which would also work as a start cap. Clifford Heath |
| Rheilly Phoull <rheilly@bigslong.com>: May 06 03:41PM +0800 On 6/05/2019 12:17 pm, Dallas wrote: > capacitors. So they specifically call them "motor starting" > Am I wrong to assume that those caps starting on page 15 are motor run > even though they don't specifically say motor run? That's what I would do considering they are polypropylene and not electrolytic. |
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