Re: Transformer oil

To: tesla-at-pupman-dot-com
Subject: Re: Transformer oil
From: "Roderick Maxwell" <tank-at-magnolia-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Thu, 02 Dec 1999 12:30:46 -0700
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

> >Hi Roderick
>
>   From my experience with Mylar (polyethylene terephthalate), it holds up
> well in petroleum based transformer oil.  I have several transformers
> using Mylar insulation on the windings.  One such transformer, 13 kV -at- 10
> kW, had a burnt turn in a winding a year ago.  Upon repair, I found no
> deterioration of the 0.007" Mylar or 0.060" polyethylene used extensively
> in all the windings.  This was after 3 years of operation.  Chemical
> resistance to hydrocarbons is good per all the performance charts I have
> seen.
>  I would stick with Mylar for your application.

   I'm glad to hear that since I already have wound 23 layers!

>
>   A tip on winding enamel wire directly on Mylar, or any other slippery
> material.  Spray a fine layer of contact adhesive spray on the Mylar
> before winding on the wire.  3M makes some as well as other manufactures.
>  When you wind the wire on the dried adhesive, it will stay in position
> quite well.   Of coarse the mineral oil will attack the adhesive after it
> is completed and immersed in oil, but  the wire will be in proper
> position and tension to stay in place at that time.
>
> Hope this helps
>
> Kevin E.
>

     I am using two layers of 1 mil thick mylar between each layer. After a
layer is wound it is coated with epoxy resin and allowed to cure for at
least 24 hours. This adds additional insulation and also keeps the wire in
place. The wire is 24 guage heavy Nyleze. I chose to use this because it is
double coated. The voltage rating on the enamel is around 4Kv. The voltage
difference between layers is only around 300 volts.
   Thanks for the info!


Frankensteins Helper

Max