Re: transformers in oil?

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

Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

Oil immersion is a standard HV technique.  Not only does it provide better 
cooling, but the breakdown voltage of oil is substantially higher than that 
of air.

All those transformers you see hanging on power poles and sitting on 
concrete pads are full of oil.

Issues with oil immersion:
1) Leaks... oil is messy
2) Servicing.. when you need to change something, you've got to pull it out 
of the oil, bringing back to point 1: oil is messy
3) oil is heavy.. not a problem for a big multi thousand pound transformer 
sitting on a concrete pad, big problem if you're trying to lift it into the 
back of your car.
4) you need to keep the oil reasonably clean and dry if you are concerned 
about dielectric properties.

As for containers, anything will do, but remember #1, above...   Most all 
plastic containers with lids leak a bit, no matter how much silicone you 
glop on. I don't know whether it's because you can't get them clean enough 
or the flexing under temperature and air pressure changes, or what. Plastic 
also cracks.

Big PVC pipe and fittings work quite nicely, and can be glued to be oil-tight.

Rubbermaid-type plastic work, in the short run, but eventually, you'll 
spill. The white 5 gallon buckets work fairly well, but it's hard to get 
wires in and out with an oil-tight seal.

Metal tanks are used in industrial equipment, usually with gaskets and 
breathers designed to keep the oil in and water out. The metal tank also 
provides a way to ground the enclosure for safety. But, metal tanks are heavy.

At 12:08 PM 2/24/2003 -0700, you wrote:
>Original poster: "James Brady by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
><jbrady-at-ajtech-dot-com>
>
>you can actually put the transformer directly in oil??? what kind-of
>container does it have to be in?
>
>i have never seen anyone do this. i guess, that the purpose is to keep it
>from over heating?