On 07 Sep 2005 23:22:03 -0400, Greg Menke
wrote:

RoyJ writes:

OK, ya got me. I've never seen a fully oil submerged welder(only a
similar sized pole transformer rated 4130/120/120 at 5 kva). Contacts
submerged in oil does not sound like a good thing.

I've been told oil makes a better dielectric than air, so there is less
arcing as the contacts approach and faster quenching of the arcs that
form. OTOH, the oil also should be free of water and crud which
presumably starts making it more conductive.

Oil will also move heat out of an assembly faster than air convection.

I have a high voltage relay downstairs, supposedly will switch up to
something like 20kv once its oil bath is filled- though I've not
actually tried it...


The switch on my big press is supposed to be a oil bath switch. It
was made that way so that it would be explosion proof in a fashion. Of
course this was a long time ago and it probably came out of a cotton
gin/elevator where the dust can cause explosions. My problem is that
since I have to keep the press outside the bowl for the contacts will
fill with water when it rains. I have to be sure and dump it before
plugging it in each time.



Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm