Re: Which oils..Capacitor oils
From: Bert Hickman[SMTP:bert.hickman-at-aquila-dot-com]
Reply To: bert.hickman-at-aquila-dot-com
Sent: Thursday, November 27, 1997 2:07 AM
To: Tesla List
Subject: Re: Which oils..Capacitor oils
Tesla List wrote:
> From: Matthew Mills[SMTP:megavolt-at-usa-dot-net]
> Reply To: megavolt-at-usa-dot-net
> Sent: Wednesday, November 26, 1997 1:24 PM
> To: Tesla List
> Subject: Which oils..Capacitor oils
> Hi, (again)
> Im wanting to know what oil to use (Im in New Zealand not America) I
> have contacted Mobil and Shell (Sell havent got back to me yet) Mobil
> carry Mobilect 34 and 35 which are bothe the same transformer oils
> except one has an inhibitor added.
> Mobil aslo have Whiterex mineral oil which is USP and BP standards
> There are 3 types which differ by their viscosity.
> at 20°C one is 24.2cST viscosity another is 124 and the other is 250
> What do I use?
> Is this Whiterex the equivalent of USP mineral oil?
> Thanks in advance,
Preferably go with either the Shell or Mobil Transformer Oils, since
they have undergone refining steps which make them better suited for
high voltage applications. For use a cap oil, an oxidation inhibitor is
not necessary or desirable - use the uninhibited variety. Now, while the
oil companies won't recommend, or guarantee, that their USP (or
equivalent) grade of mineral oil will work as a dielectric oil, in
reality, it will. However, it MAY not be as "dry" as transformer oil,
and thus may not have a high a breakdown voltage. Many coilers in the US
have used veterinary grade white mineral oil (animal laxative) in their
caps with good success. Transformer oil viscosity is typically in the
100+ centistokes area at room temperature - sounds like the 124 cST
variety would be about right. I don't know about Whiterex, but if it is
pure enough to be used as a laxative in either animals or humans it
should work OK in your caps.
Safe cappin' to you, Matt!
-- Bert --