Re: Why PT's?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Brian" <ka1bbg-at-webryders-dot-net> 

there is a replacement for a pt, electronic in nature..i havent see one but
pt's are a thing of the past for new installation i am told. those pt's
lasted for years, built and durable my electrician friend says those things
only die from a direct strike from lightning. cul brian f.

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, November 26, 2003 12:13 AM
Subject: Why PT's?


 > Original poster: "Lau, Gary" <gary.lau-at-hp-dot-com>
 >
 > Here's a question I've always wondered about.  As I understand it,
 > potential transformers are devices designed to step down a 14.4kV or
 > whatever transmission line to a more manageable 120V signal that can be
 > more easily read by the utility companies, so they can see what's
 > happening on their HV lines.  Basically a step-down transformer with a
 > precise turns ratio and a minimal power handling capability, but happily
 > enough so that it's useful in "our" application.
 >
 > These are big, heavy devices.  I would think that a solid state
 > optically isolated equivalent could be easily produced.  Why are these
 > dinosaurs still used by the utility companies?  And why a 120V output?
 > I'm grateful that these devices work so well for our application but...
 >
 > Gary Lau
 > MA, USA
 >
 >
 >