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Does capacitor size matter?

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#21 ·
mrkelly said:
Point being TB,is, the OEM cap was a 70x7.5
I replaced with the same and after the load test was presented with 83 on the comp side.
Most Scroll's have the run cap info Today on the sticker but I was just going with the OEM cap info.
:confused:
Click to expand...
SOunds like the true value of the new cap under load sbowed you needed a different 70 uf cap.
 
#22 ·
I imagine that in a pinch, you could try different capacitors and look for the lowest amp draw. Sort of like when you make a three phase motor run on single phase, you just keep trying different values until you get the best amp draws.
 
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#23 ·
SOunds like the true value of the new cap under load sbowed you needed a different 70 uf cap.
Click to expand...
I'm 'tellin Mom on you....;)

So,why when I changed the OEM,then changed again was 'presented' with the Same number?
 
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#24 ·
if a VERY small change in mfd is such a bad thing.
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Actually,Yes.
When I was dealing with this Blower motor,US Motor,1/3 hp swap on the Ducane horiz with the GE OEM motor and was over amping by .5 so I swapped out the 7.5 to a 10. The Amps went Up by 1 Amp,as in another .5.
I'll keep tab on the rest of my Dual's change out on Cond's and SEE what is going on.
Again,I wish the OEM's would put the Start Winding Amps of the Comp ON the Nom plate.
Then we can maybe figure this out.
 
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#25 ·
You really have to go with what the manufacture specs. You could be there in the early morning and one capacitor could be great, but in the late afternoon when the voltage drops it could be a different story. Go with the OEM because they've tested different run conditions. They one thing I do is replace 370 with 440, but am I sacrificing the motor, for less capacitor replacements? It used to be the capacitor would act as a fuse in over voltage condition, with the new motors I'm not sure that is true anymore.
 
#26 ·
Used to be no problem but Today is always an 'Issue' of not If but When.
Quick check I do now is physically Touch the run cap,
Amazing what your 'touch' can tell ya......:whistle:
 
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#27 ·
also, imagine you over size a capacitor by 5mfd as your example. It was a 35 mfd and you pput a 40 in because you did not have a 35. The next guy comes alsong. He does not have a 40 but puts in a 45 mfd. Now, it is 10 mfd over sized. Now years later, the new Ac guy puts in a 50 because he did not have a 45. Get the picture?
 
#28 ·
Exactly bud. :cheers:
 
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#29 ·
I've got a 55, that should work.


Gunslinger said:
also, imagine you over size a capacitor by 5mfd as your example. It was a 35 mfd and you pput a 40 in because you did not have a 35. The next guy comes alsong. He does not have a 40 but puts in a 45 mfd. Now, it is 10 mfd over sized. Now years later, the new Ac guy puts in a 50 because he did not have a 45. Get the picture?
Click to expand...
 
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#31 ·
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