Sewing machine Pfaff 332 motor capacitor replacement

[sailor83]

Hello everyone!

I have this old Pfaff 332 sewing machine with a blown capacitor, it takes out the mainfuse. Have removed it and everything works as it should. But I think i need to put in a new one, but can't really understand the schematics of the old one. (the capacitor is supposed to reduce radio noise as well as sparking on the carbon brushes, from what I've read)

The old one: TYPE 1210BD/1 (0.1µF + 2x2500pF)

The main supply comes into the screw socket and passes through the capacitor into the magnet coil around the rotor in the motor.
Tried drawing the circuit printed on the capacitor.

My guess it that the 0.1µF is connected over the main supply, and one 2500pF from each lead to ground, hard to tell by the picture, and circuit drawing.

Ordered a new one from Kemet: PZB300MC11R30 it has X2 and Y2 rating, 100nF between end pins and one 2.2nF between end pin and center pin.

One leg on each of the supply and the center pin to ground is my plan. The supply here is 230Vac, the capacitor says 275vac, is that sufficient?

Am I correct or way out?

[SeanB]

Correct, the original was made by winding the wires with the foil, so that the ESR of the device contributed to the noise reduction, and then the whole assembly was put into the aluminium body. The new one is done as you described, it does the same function, you just need to extend the wires to it, or mount it near the screw block.

[SilverSolder]

I only see 4 wires in total go into the old capacitor (two at each end) -  is the aluminum case itself connected to Ground through its mounting?

[sailor83]

Yes, on the rear of the image there is a screw connected to ground.

Thanks SeanB, I'll extend the wires a bit and put some heatshrink over the metal pins to avoid it coming in contact with something it shouldn't touch.