Re: Filling caps with oil

From: 	gweaver[SMTP:gweaver-at-earthlink-dot-net]
Sent: 	Wednesday, December 03, 1997 2:42 PM
To: 	Tesla List
Subject: 	Re: Filling caps with oil

At 07:35 PM 12/3/97 -0600, you wrote:
>From: 	Jim Fosse[SMTP:jim.fosse-at-bjt-dot-net]
>Reply To: 	jim.fosse-at-bjt-dot-net
>Sent: 	Wednesday, December 03, 1997 1:06 PM
>To: 	Tesla List
>Subject: 	Re: Filling caps with oil
>On Tue, 2 Dec 1997 23:32:59 -0600, Tesla List <tesla-at-pupman-dot-com>, you
>>From: 	David Huffman[SMTP:huffman-at-FNAL.GOV]
>>Sent: 	Monday, December 01, 1997 3:21 PM
>>To: 	Tesla List
>>Subject: 	Filling caps with oil
>>Hello All,
>>I finish 2 of the 3 caps this weekend and had a couple of questions for
>>those who have been there before.  I added the oil and pumped on the cap
>>with a refrigerator compressor. The oil foamed quite a bit and I had to stop
>>pumping a few times to let it settle down. The Kraft paper seems to hold air
>>in small spaces and generated tiny bubbles (foam). The trapped air seems to
>>be diminishing and I hope to use the caps soon. How much pumping should I
>>do? One problem is the terminals through the sides of the PVC pipe leak so I
>>have to continually pump to keep a vacuum. I haven't figured a way to seal
>>them although they don't leak oil. By the way 25 in-Hg seems to be the
>>limit, does that sound about right? I will hall them into work tomorrow to
>>check the capacitance on our fancy C-meter.
>>More to come...
>>Dave Huffman

You need to pump a vacuum on the caps then close a valve between the pump
and caps so the vacuum in trapped in the caps.  Put a guage on the cap and
watch to see if the guage drops.  If the guage drops that means you have a
leak.  If the guage holds then open a 2nd valve and the vacuum will suck in
the oil threw a hose from your oil container.  It takes a few minutes for
the oil to fill the cap.  It takes about 15 minutes to fill my .01 uf caps
which are in 6" x 16" PVC pipes. When finished remove the fittings and take
a look to see if the cap needs any more oil.  I usually have to add about 1
or 2 tablespoons of oil to my caps after removing the pump and fittings.  If
you try to pump a vacuum on the cap with oil already in the cap the lower
pressure will make the oil boil at room temperature and it will foam and
bubble out of the capacitor.  If you made a mistake and put oil in your cap
before pumping the vacuum then try to dump out the oil and start over.  Pump
a vacuum on the cap and let the oil foam for awhile to make it all boil out.
It may take several hours to make it all boil out.  Hope this helps.

Gary Weaver