3 suppression capacitors in one package help - Page 1
Forum section: electronics / repair

author: almared
author_rank: Newbie
timestamp: May 26, 2020, 04:28:38 am
content: Hi all, so I like to fix things and know a thing or two about simple electronics. I was given a nice vintage sewing machine by a friend that needs a little repair. After taking it apart, I found that the suppression capacitor on the motor ia blown but luckily all info is readable. The issue is that this is not a normal capacitor but 3 in one package. The label reads the following:F1740-350-5070,05uf (class x) +2x2500pF (class Y)The capacitor has 5 leads two for the input side and 2 for the output leading to the motor coils and one ground (even though the machine is not grounded)There is a little diagram also on the capacitor and I'll try to upload some pictures to this thread.Now my local supplier doesn't sell these because they're old but they sell the 3 caps separately. Is it possible to buy the three caps and connect them myself? My assumption is that they should be the same if one connects them correctlyPlease check the pics and I appreciate any helpEdit: I attached a picture of what seems to be like the correct way to connect the caps together.

author: DaJMasta
author_rank: Super Contributor
timestamp: May 26, 2020, 05:11:41 am
content: Haven't seen the combo capacitor myself, but the arrangement of parts looks like a standard mains input filter - the kind that is often integrated into the mains plug or is the first stage of the power supply board on most modern equipment. A line filter could probably replace the whole unit, but appropriately rated capacitors (X or Y class, depending on which) wired in the same way would do just as good of a job as the original.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 26, 2020, 08:49:59 am
content: Don't think I've seen that particular style but I have a few RIFA (you know, the yellow molded kind that cracks up over time) that are multi-part.Yeah, just replace with equivalent types, the larger will be X2 rated and the smaller will be Y1 rated.Tim

author: kastell123
author_rank: Contributor
timestamp: May 26, 2020, 10:43:25 am
content: Mira esto, Important, for your.

author: kastell123
author_rank: Contributor
timestamp: May 26, 2020, 10:51:11 am
content: According to the photo I don't think they are wrongDo you have a capacitormeasure its capacity between the 3 capacitors (which are in parallel) you have to see the individual capacity the 2 with the lowest capacity 2k5 = 2500pf / 250v( estos 2 Important arranque motor) the other 0.05UF = 50K 250 v (solo es supresor, no important.Suerte.

author: almared
author_rank: Newbie
timestamp: May 26, 2020, 03:53:33 pm
content: Thanks. But what arrangement and can just one cap replace all and what would be the value of that cap.

author: almared
author_rank: Newbie
timestamp: May 26, 2020, 03:56:24 pm
content: Quote from: kastell123 on May 26, 2020, 10:51:11 amI was today at my supplier and I was only able to get the 0.05uf one and the other I will have to wait a few days before they're here.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 26, 2020, 04:27:13 pm
content: 0.047uF or 47nF may be the more common value. It's noncritical.Connection is as shown in the diagram, GND to the two small caps, L1 and L2 to the rest.Tim

author: kastell123
author_rank: Contributor
timestamp: May 26, 2020, 08:26:48 pm
content: Filter testingwith capacitancecut the thread marked with xTotal capacity = 0.051 MfI insist as seen in the photo this filter is OkWhat is wrong with the machine?

author: almared
author_rank: Newbie
timestamp: May 26, 2020, 10:18:15 pm
content: Quote from: kastell123 on May 26, 2020, 08:26:48 pmSo I cut it then?The motor has a blown capacitor and thus open circuit. Today I got only a 47nf x2 capacitor which I assume should work. Should I wire that across the two wires after removing the old cap and ignore caps c2 and c3 that connect to the ground? Will that work?

author: almared
author_rank: Newbie
timestamp: May 26, 2020, 10:19:31 pm
content: Quote from: T3sl4co1l on May 26, 2020, 04:27:13 pm

author: almared
author_rank: Newbie
timestamp: May 27, 2020, 02:35:45 am
content: Thanks all. I think problem solved. I removed the cap and connected the wires directly then attached a 47nf x2 cap across. I didn't install the other caps connected to the ground wire and I cut that too because the machine doesn't have a ground. The motor runs like a butter with no sparks or noise. I hope that this is ok and doesn't ruin the motor in the long run. I attached a picture of the final work.