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You can get appliance capacitors from any appliance parts shop. The best thing to do is take the old one in and let them match it. The physical layout doesn't matter to the appliance but it can make it a lot easier to mount the new one without modifying clamps, connections etc.
If not, there are good appliance-parts sellers online. The very best way to match the part is to look for the exact appliance model, find a parts list and get an exact-number replacement. Or you can call/email most of them for advice. Try AppliancePartsPros and RepairClinic (both dot-com).
In general, these are "loose" or bulk-function components and don't need close matching. The only really critical value is 30MFD; a replacement should be that, exactly, or slightly plus - 30-32MFD. Voltage must ALWAYS be the same or higher; should you happen to find one rated for more than 250VAC, you can use it, but it may be physically larger. The temp rating is high but nearly all metal-can capacitors for AC/appliance use are rated to about that. You should match that value. Going lower (70 C is common) is not recommended, although functionally it would probably be okay. Higher is fine but likely to be more expensive.
Hz is pretty much irrelevant and I don't think I've ever seen an appliance cap that wasn't rated for both 50 and 60 Hz.
So: getting a pro to hand you an exact or suitable replacement is best. If you buy it yourself, match all four characteristics but mainly be sure it's 30(-32)MFD and at least 250VAC.
Motor Start Capacitor. 30-36 MFD UF / 220-250 VAC
Rated at 30-36 uf 165 Volts 50/60HZ.
Operating temperature range: -40C to 65C (-40F to 149F)
Will the above work for my appliance ?
Probably.
Are there any downside in above spec?
The design rating at 165 volts suggests intended use at 120 volts RMS (which has a peak voltage of 165/170).
The breakdown rating at 220/250 means it probably won't catch on fire.
The allowed variation of 30-36 means it may be cheaply made and luck of the litter.
Thanks for sharing.
If it is cheap and you can easily test it in place but with access before buttoning up, it might be worth giving it a try. If, OTOH, you run across a cap that is MIL SPEC, pick it up instead.
the higher voltage rating has nothing to do with the cap catching fire or not when it has a higher voltage rating .
the back emf generated by a spinning motor can see 2x the voltages generated compared to what it is fed with . .
mars starting relays are designed to pick up the start wingdings and start cap at voltages much in excess of the voltage coming in.
you can see the voltages generated by the motor spinning here . the pick up voltages are the voltages needed to operate the relay that brings the capacitor in and out .
you can see they exceed the 120v and 220v the motors may get fed with .
But the layman has no idea that the voltages generated by the motor can far exceed the running voltage of a motor .....the thought that the internal voltages can run more than 2x can be baffling.
OK, but with the caveat that the design specs of the cap. and circuit are spozed to take all of that into account. The actual in-use breakdown voltage of the cap can be much higher than the specs, but not made apparent to the buyer to keep them from being stupid... and... current kills, while a high transient voltage can be little more than a nuisance when properly handled, as by the MARS.
If you want to go crazy with killer voltage, work with flyback transformers that have a CRT in the circuit as a type of capacitor, or play with a Tesla coil.
Bottom line though, I think the cap he cited has a chance of working for him. We're just playin' here.
the worst thing for capacitors is actually harmonics ... the harmonics can generate ridiculous spikes .
the company i worked for got sued by an electric utility when some capacitors on some water pump motors exploded .
creating electricity is a dirty business power wise and experts we hired traced the cap explosions to sever line harmonic from creating power and not faulty caps
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