Re: Poly Dielectric Strength

To: tesla-at-grendel.objinc-dot-com
Subject: Re: Poly Dielectric Strength
From: "Malcolm Watts" <MALCOLM-at-directorate.wnp.ac.nz>
Date: Mon, 26 Feb 1996 08:04:25 +1200
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Hi all,
       A comment on this....
> 
> What I'm seeing is that the poly purchased on the East Coast seems to have a 
> 
> higher voltage rating than towards the west...maybe a different regional 
> manufacturer?
> 
> Anyway, I would set the limit for 60 mil poly purchased in Dallas Texas at 
> 7500 volts input.
> 
I discovered to my horror that firms selling plastic sheet usually 
take the manufacturer/distributor figures at face value. I went to
purchase some 0.25mm poly last year and "felt" it as being thin so
I raced back an grabbed a micrometer to measure it. Turned out that
what they would have sold me measured more like 0.21mm (sorry about
the metrics - what we use here). It also transpired that they had
a complete roll of the real thing that they thought was crook be-
cause it was liberally coated with talcum powder. I bought that
entire roll on the spot. Moral - measure if in doubt.

Malcolm