I think the confusion arises from the OEM part being listed as a start capacitor. This may be from a loss in translation from Mazzer. This also may be because the motor will not start (nor run) without a run capacitor. By all appearances it looks like a 30 mfd run cap. The numbers Assaf checked confirm this. Your Handle info states you are in central New jersey. A quick google search shows a half dozen electric motor repair shops between Trenton and Newark. I will take one of them approx 30 seconds to test a capacitor and any one of them will have something compatible in stock, probably under $10. If its not the cap then they should be able to tell you what. This a simple test. Someone might be open today.

Well all this interesting discussion leads me to another question that I don't know if it belongs here or in it's own new thread.

The 'Operating Manual' of our K30 says, "6sec. on; 60sec.off" for 'Max. Permissible Running Time of the Grinder'.

My question is why?

Is this because the capacitor(s) cannot safely sustain a longer run time or is it the motor itself?

I would imagine it's the caps.

Might it also be to keep the burrs from heating up or a combination of factors?

BaristaBoy E61 wrote:The 'Operating Manual' of our K30 says, "6sec. on; 60sec.off" for 'Max. Permissible Running Time of the Grinder'.

My question is why?

Is this because the capacitor(s) cannot safely sustain a longer run time or is it the motor itself?

It can be the cap but I don't suspect a 1-10% saving on a <10$ cap (OEM prices) would be worthwhile for the manufacturer.

So I think it is much more likely to be the motor. A smaller motor is much less expensive. Less expensive to ship (lighter and smaller), requires smaller fan blades, etc.

My Bamix mixer also has a 5 min limit on runtime.

Perhaps, however the motor in our Mahlkonig K30 Vario is a lot more powerful (+¼HP) than our 2-car electric garage door opener. So what am I missing?

A few beans vs a heavy (albeit balanced) garage door...

BaristaBoy E61 wrote:Perhaps, however the motor in our Mahlkonig K30 Vario is a lot more powerful (+¼HP) than our 2-car electric garage door opener. So what am I missing?

A few beans vs a heavy (albeit balanced) garage door...

Think of it as Max Power (above which the motor would stall) - vs Max sustainable power (max power when running 24/7 - above which it would overheat).

A powerful motor with endurance (e.g. An electric car motor is very expensive). A similar max power motor that runs on a 10% duty cycle (e.g. 1 minute on, 9 off) is substantially cheaper.

Garage openers have an even lower duty cycle than a grinder. Can afford to run small and periodically hot.

does everyone agree that the Mouser one is ok for me?

http://www.mouser.com/ProductDetail/KEM ... E2EALw_wcB

if so, I'll just order it. If anyone is not sure, I'll find a motor repair shop and just bring the grinder in for their assessment.

thx again......

drtzali wrote:does everyone agree that the Mouser one is ok for me?

Didn't you decide that you want to buy a run capacitor? The description for this one says it is a start capacitor.

Rocky

4th lesson of this thread: Don't ever trust a reseller / distributor site: look at the datasheet for the C87 series capacitor.

They are run capacitors.

Mouser made the same mistake espresso parts did.

In electronics - only ever trust a datasheet - it is the only source for reliable data about components.

Additional info (for those interested in a deeper dive): note that the C87 series data sheet says run capacitor - and a telltale sign that it is indeed so is that it does not mention duty cycle and intermittent duty at all. It is for continuous use 24/7. The C87 capacitor is therefore a direct replacement for the grinder run capacitor.

Compare that with the datasheet for a start capacitor - another Kemet capacitor series called the MS/MD line:
http://docs-europe.electrocomponents.co ... 3636bd.pdf
Reading this datasheet, apart from stating it is a start capacitor, it mentions a duty cycle of 1.7%. This is the telltale sign that indeed the MS/MD line is the wrong component for the grinder

You might want to double check the dimensions listed in the datasheet.
After all this it would be a bummer if it didn't fit!

AArhgggghhhghhhh

*breathes calmly*

is there consensus of any kind of what I should do? I'd rather not spend $80 on espressoparts, but if that's the only option, that's what I'll do. If there's a cheaper one that's just as good, someone PLEASE point me to it.

Incidentally, I've had the one I got from sustainable installed for the past week or so, and the grinder is working fine. Not that it won't detonate at some point, but at least I'm getting my coffee.

thanx again to all you knowledgeable people for your help.