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by lazide 614 days ago
It’s not so much that they are fragile, as they’re a part that gets a lot of very heavy duty use and they’re expensive to make invulnerable. Ain’t no residential customer going to pay for a 100mfd 240v tantalum cap (how big would it be even?).

Think of them like a car starter motor or transmission (for old ICE vehicles).

Assuming we’re talking motor start capacitors anyway. For most of them, every time the compressor starts they see a dead short at 240v for a couple milliseconds, typically in the 10,000+ amps range.

And most people use their AC the most when it’s hot and nasty out. Which doesn’t help.

1 comments

By "mfd", do you mean µF? I have some basic knowledge of electronics and am not familiar with "mfd" in this context but assumed you must mean microfarad.
Apologies, yeah most motor start caps for some reason use mfd to mean micro farads. [https://www.packardonline.com/electrical/capacitor/motor-sta...]

I guess from before the days of Unicode?

µF == the same thing, but tends to be the ‘more correct’ modifier used in electronics and engineering, rather than industrial parts supplier catalogs.

Oh, wow, this is so bad. m usually means "milli" not "micro". At least they could have used u instead of µ, which is a more common replacement when you don't have the keyboard character available.
Just wait until you see the actual dimensions of a 2x4!
I owned a house once that was balloon framed, with 2"x4" black walnut studs in the walls.

They just don't make things like they used to. :)