Bernina Sewing Machine Capacitors

[chish13]

Hi everyone, newbie on here and a very basic DIYer.
I have a Bernina sewing machine that has popped the capacitor on the motor, the capacitor has a diagram on it that looks like it is a 4 in 1 type cap and i was wondering if i get individual film capacitors of the same values and soldered them together as the diagram that this would work? Diagram from the original capacitor attached. Thank you in advance.

[blabbersnitch]

Hi Chish,
The answer is…. maybe.
You would want to know a bit more before you went ahead.
What voltages are we working with? The capacitors would have to be adequately rated for the voltages they will be exposed to.
Also, is this one module with four terminals coming out (do you have a photo)? And is the resistor inside the module (will you have to replace the resistor too?.. it will have a power rating, and with such a low value, any appreciable voltage will generate a lot of heat).
The values are not standard values, you would have to approximate, but that might not matter.
Let us know if you have any more info you can share.
Eric

[TonyDuell]

I would guess that '2.2mOhm' should actually be 2.2MOhm, and that this is a simple discharge resistor across the manin. It would have to be rated to stand the mains voltage but other then that no problem.

If the green/yellow wire is earth, then the 2 capcitors connected to it should be class Y. The one across the mains should be class X.

What does the white wire connect to?

[DMcMahon]

Yes 2.2MOhm as per this linked Thread :-

https://www.vintage-radio.net/forum/...d.php?t=185196

David

[chish13]

Hi Eric
Voltage is 240v and the rating on the capacitor is 250v, pic attached of the actual unit, all in one, the resistor is under the white sheathing * the capacitors ive been looking at are rated at either 1.6kV and1000VDC and their values were spot on apart from one that is 0.062uF rather than 0.06uF.
There has been a previous post by Uncle Bulgaria fixing this same problem but as i dont know what X2 and Y2 capacitors are so i dont understand his solution. Previous thread here if it helps.

https://vintage-radio.net/forum/show...hlight=bernina

Stuart

[Lucien Nunes]

Because these suppression capacitors are connected to the mains and to the chassis of the appliance, they should be replaced with types designed for this duty and meeting the applicable safety standards. This is what @TonyDuell is referring to; class X and Y caps are intended for their respective functions, across the mains and to chassis respectively, and have defined failure modes that will avoid the chassis becoming live if they fail or are damaged by mains transient voltages.

You can probably buy the delta capacitor incorporating the two 2nF class Y and the 60nF class X as a complete unit with three leads as this is a standard configuration. Obviously the type that looks like the original, with insulated leads, is the most convenient. Search for delta capacitor / delta suppressor / line filter etc. The capacitance values are not very critical, you won't match the existing ones exactly. The other 20nF capacitor between black and white I believe suppresses the speed control. That you might have to replace as a separate item with a 22nF class X.

The resistor is a bleeder to discharge the X cap to prevent shocks from the mains plug. This might not be incorporated in the replacement delta cap. If you choose to add it, as Tony mentions although the power dissipation is negligible it should be designed for at least 350V, preferably 500V and adequately insulated. Be sure that any changes you make do not compromise the creepage and clearance distances between live parts and the case

[chish13]

This info is great thanks all, I will have a look online to see what's available, regarding the resistor could I not just use the one attached to the old capacitor?
I have found a place in Norway that specialises in these capacitors but they seen expensive @ £42 plus duties.

[ex 2 Base]

I have fixed my wife's Bernia mechanical wise, with spare from parts Bogad Machine Co. 50/55 Great Sutton St. London, phone number used to be 0171 2531198.Take a heart pill before calling, mods please delete this if its an infringement. Ted

[Uncle Bulgaria]

Originally Posted by chish13

This info is great thanks all, I will have a look online to see what's available, regarding the resistor could I not just use the one attached to the old capacitor?
I have found a place in Norway that specialises in these capacitors but they seen expensive @ £42 plus duties.

Assuming a 707 or similar like mine, you need one of these. Then, as Lucien says, just another 2.2nF X class for the fourth.

In the photograph I posted (in my repair thread previously linked), you can see the two yellow boxes (the delta in the eBay link, and the extra 2.2nF one), with a new resistor inside the heatshrink somewhere in the middle. You could use the old resistor, but it'll probably be a pain to dig out from the encapsulated capacitors, and possibly covered in nasty ancient capacitor gunk of unknown hazardousness.

[chish13]

Thanks Uncle Bulgaria items bought!
Thanks to everyone for their help and input, it's greatly appreciated.

[Nickthedentist]

Originally Posted by ex 2 Base

I have fixed my wife's Bernia mechanical wise, with spare from parts Bogad Machine Co. 50/55 Great Sutton St. London, phone number used to be 0171 2531198.Take a heart pill before calling, mods please delete this if its an infringement. Ted

Different contact details now: https://www.bernina.com/en-GB/Footer...ges/Contact-us

The Gt Sutton St address seemed to be still valid in 2008 and then become "Domus" and now be derelict, according to Google Streetview.
https://www.google.com/maps/place/50...g%2F11c24cl4mf

[Kevin67]

I am looking to replace a Bernina Record 530 original capacitor it, looks like the one in Chish's diagram.

Please any advice on best way forward would be most appreciated.