Power supply potting

[poiuy]

Hello,
I'm trying to learn more about the advantages of encapsulating/potting a power supply (it's an electronic ballast, 1kW)
Particularly I am interested in what potting would buy me other than environmental protection for components, what are the advantages of potting vs. non potting. For example is there any quantified effect for the heat transfer, would it be possible to increase the power density (and by how much, roughly) when using potting. Also, what is the cost adder for a potted ballast vs. non potted and what are the technical difficulties (if any) for potting an electronic ballast.
Sorry, lots of questions, any information would be greatly appreciated.

 

[MacGyverS2000]

Reduction in arcing?

 

[sreid]

One down side is that potting make the electronics virtually unrepairable.

 

[ScottyUK]

sreid,

That 'downside' depends upon whether you are in the market of selling replacements!



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If we learn from our mistakes,
I'm getting a great education!

 

[poiuy]

Our goal is to have reliable products not to sell replacements
We do not repair our ballasts, regardless if they are potted or not.
What I'm trying to determine is what potting would buy us and how much do we have to pay for it.

 

[sreid]

If the electrical parts are in an enclosed box, potting will usually increase the heat transfer to the case (almost anything is more thermally conductive than air). Most potting will exclude moisture (and some chemicals). It will stop some vibrations and attenuate acoustic noise.

People preceive heavier things as higher quality.

I would suggest contacting Dolph about the application and costs.

http://www.dolphs.com/

 

[buzzp]

The potting can also reduce the spacing requirements inside, for conductors of opposite polarity. On the down side, potting equipment generally leaves air bubbles. I have heard that in the right cases, these bubbles can heat up enough to actually break apart or explode, if you will, the equipment contained in the potting. One customer reported this to me but I have no first hand accounts of this happening. It seems entirely possible.
The other down side is it is extremely messy. Not sure if you would buy equipment for automatic dispensing and mixing or not but mess is a concern. We had an auto mix/dispensing machine and it required a lot of PM (preventative maintainence) and if the operator slacked on the maintainence the machine would seize up (two part epoxy would set up if they did not clean well).
As far as the added heat dissipation, it has been my experience that this is negligible. However, I was dealing with much smaller wattages than your likely dealing with (mine 5W).