On Oct 8, 10:51*pm, RoyJ wrote:
I'd probably go with the next size larger (still within the specified
range), should give a bit more starting 'kick'http://www.mcmaster.com/#7245k54/=3z859g



Denis G. wrote:
On Oct 8, 9:03 pm, dave wrote:
my ancient 4hp sears craftsman air compressor needs a starting
capacitor, I've determined (through a process of elimination). I still
have the original owners manual, and the capacitor is "part of the
motor", not shown in the parts blowup, or parts list, as a seperate
orderable part. further, the friggin' thing seems to be a 'non-standard'
mfd rating, too (it doesn't 'fall into' any capacitor size-groups of any
maker's starting cap's I can find online. matter of fact, it's not even
close):

the one in it now is
110 volt, 485-580 mfd
mallory #139852-49
seems a slightly non-standard SIZE as well:
diameter: 1 13/16ths inch, and
length, overall, excluding 'spades': hair over 4 5/16ths (but clearly
under 4 3/8ths)

atttempts to locate same by the mallory part number on it entirely
unsuccessful. so (physical size and 'look' issues aside) can I "daisy
chain" two cap's and achieve the same net effect, somehow? appearance
"not an issue", I just need a working compressor. I know I can replace
the cap with a higher voltage cap, and that'd be fine (maybe even
desireble) but what about the mfd rating? if I must, is it best to go
'bigger mfd numbers' or lesser?

thanks for tips on this, guys :-)

It looks like the value of the cap is not that critical. *They give
you a range 485 to 580 microfarads. *The average value is
approximately 540 microfarads. *If you order from McMaster Carr, this
should work: *http://www.mcmaster.com/#7245k114/=3z7b3b- Hide quoted text -

- Show quoted text -

Roy, you're probably right, however, I wonder that if you skew the
value to the higher end if you pay a price by decreasing the life of
the contacts on the centrifugal switch.