[Amps] Measuring amp B+

[K1SG at aol.com]

Hi Randy,
 
I've been using my 80K6 HV probe quite successfully and safely for  
measuring HV in KW amp power supplies. Do follow the instructions, and my policy  
is to set everything up, make the connections, and then turn on the supply. 
Take  all of the usual precautions to make sure HV is ALL the way down, 
unplug, use  bleeders and a chickenstick, then measure the voltage to make sure 
it's down to  zero before disconnecting.
I believe the concern is that this kind of probe can be used for  measuring 
PS voltages at amateur levels, but should not be used for measuring MV  
voltages on AC lines (14.4 KV, with no fuses or breakers to protect you.)
 

I'm speaking from limited personal experience only, and this should not be  
taken as gospel...perhaps one of the more serious HV guys could comment 
further,  so please no lawsuits!
 
I am reminded of this video, though...I know it's been referenced here  
before, but I had to go look again.
_http://www.glumbert.com/media/highpower_ 
(http://www.glumbert.com/media/highpower) 
Don't use your Fluke probe here.
 
Steve

 
Steve  Gilbert
K1SG
K1SG at AOL.com


In a message dated 1/26/2011 5:27:00 P.M. Eastern Standard Time,  
amps-request at contesting.com writes:

Message:  4
Date: Wed, 26 Jan 2011 16:25:58 -0500
From: "Randall, Randy"  <Randy.Randall at uchealth.com>
Subject: [Amps] Measuring amp B+
To:  "amps at contesting.com" <amps at contesting.com>
Message-ID:
<5CBCD439080F744F966BB2815C060775021F7ABC530B at MAIL-B.healthall.com>
Content-Type:  text/plain; charset="us-ascii"

Hello all,

I have on the way a  Fluke 80K-6 HV probe.  It is only rated to CAT I and 
from the text below  it may not be suitable for measuring the B voltage of a 
linear amp esp. one  with a large filter cap.  Should I be using something 
rated CAT  III?

The 80K-6 is a high voltage probe designed to extend the voltage  measuring 
capability of an AC/DC voltmeter to 6000 volts peak AC or DC  Overvoltage 
Category I. This means the probe can only be used to make  measurements on 
energy limited circuits within equipment.  Examples  include high voltage 
within televisions or photo copy  machines.

Thanks
Randy  AB9GO