Re: Maxwell Capacitor - Air Bubble question . . .

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Bert Hickman by way of Terry Fritz <teslalist-at-qwest-dot-net>" <bert.hickman-at-aquila-dot-net>

Dan,

Bubbles are common in many plastic packaged pulse capacitors, and its quite 
likely that the cap came with the bubble from the factory. If the case is 
intact (i.e., not leaking oil) and the bubble small, it will have 
absolutely NO impact on the cap's performance or expected life.

Relatively large bubbles were purposely left inside cylindrical capacitors 
(for example laser and pulse caps from CP) to provide a degree of "give" 
when the capacitor innards heated up during heavy duty service. Rectangular 
packages have built-in stress relief since the flexible sides can easily 
expand outward a bit as necessary.

Best regards,

-- Bert --
-- 
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Out-of-Print Physics and Engineering Books and
coins shrunk by ultrastrong electromagnetic fields!
Stoneridge Engineering: http://www.teslamania-dot-com
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Tesla list wrote:
>Original poster: "Mccauley, Daniel H by way of Terry Fritz 
><teslalist-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>
>
>I bought a number of 37xxxx series capacitors from a local source and it
>appears one of the capacitors has a slight
>air bubble inside the capacitor. (You can hear the oil shift when you tilt
>it etc...)  The capacitor does have a fill plug and I am guessing the plug
>was either removed or leaked some air into the capacitor.
>Will this small air bubble greatly affect the performance of this capacitor
>(voltage rating?) or do you guys typically still run these things even if
>small air bubbles form in the capacitors.
>Re-filling with oil is not an easy process as they either use heated oil, or
>"compress" the package when oil filling to create a negative or positive
>pressure once the oil cools or case reverts to its original volume.
>Any help appreciated.
>Thanks
>The Captain
>
>.