New build questions

[greekie]

h = hours

[brentm]

h = hours

Can you elaborate on that? I think it must be something other than hours in terms of storage life. Henrys law of constants is the best I can figure.

[ToneMerc]

h = hours

Can you elaborate on that? I think it must be something other than hours in terms of storage life. Henrys law of constants is the best I can figure.

H is hours; now I might be wrong but I have always interpreted the smallest H ratings as the expected operating life at max voltage and max temp. Thus, if you have a 1.000H cap which is rated at 85C(185F)/450V with 450V applied at 185 degrees, it's expected life is 1 hour. The larger numbers in the 1000's of hours usually will relate to some lifespan range.

Too each his own, but new quality fresh caps are plentiful and relatively inexpensive. The bottom line is this, those Spragues don't have a 20 + year shelf life.

good luck

TM

[brentm]

h = hours

Can you elaborate on that? I think it must be something other than hours in terms of storage life. Henrys law of constants is the best I can figure.

H is hours; now I might be wrong but I have always interpreted the smallest H ratings as the expected operating life at max voltage and max temp. Thus, if you have a 1.000H cap which is rated at 85C(185F)/450V with 450V applied at 185 degrees, it's expected life is 1 hour. The larger numbers in the 1000's of hours usually will relate to some lifespan range.

Too each his own, but new quality fresh caps are plentiful and relatively inexpensive. The bottom line is this, those Spragues don't have a 20 + year shelf life.

good luck

TM

Thanks TM - I think I was overthinking this a bit perhaps.

I agree, new caps are plentiful, and relatively inexpensive. BTW - I got a response back from Sprague on the can sizes for those TVA1720s. Diameter is 35mm and lenght is 106mm. I was playing around Visio to see how I could get these to fit, and I just don't see it being feasable. I'll prolly just go with the 100uf TVAs for the B+ section and call it a day.

I did find this calculator.

http://www.illinoiscapacitor.com/tech-c ... ators.aspx

Using my expired caps as an example. The Load Life Rating is 500h (Useful life at 85 C). Maximum voltage rating is 350. Operating voltage of application is 0 (storage). Max temp is 85. Ambient temp is 22. This comes out to 78,793 hours. Which = 8.99 years.

Drop the ambient temperature down to zero and they'll last 41 years in storage. But I'm not sure if that means we should all be storing our unused caps in the freezer or not. But if ambient temp goes down, useful life goes up. To what extreme, I dont know They do state they'll operate at -20 C. Why not freeze your unused caps?