Freaky Amazing DMM?!

Arlowe wrote:
Michael A. Terrell formulated the question :
bud-- wrote:

On Jan 27, 12:14 am, "Michael A. Terrell" <mike.terr...@earthlink.net
wrote:
bud-- wrote:

Michael A. Terrell wrote:

Is it a phantom voltage?

Easy enough to identify.

Even easier for Arloe.


Proof that its easier for him?


The appropriate tools start with a well trained brain. Otherwise,
you are a monkey throwing crap at the problem.
How fortunate that Arloe and Stewart and I are well educated and know
what we are doing.

Sure you are. Yet you can't figure out how to do it without a dumbed
down tool.

It’s the favorite nobody-knows-anything-but-Michael argument.

Not the issue, of course. Any tool can be used. The question is what
is appropriate and efficient. High z meters do not help you on power
circuits, but you can use what you want. Arloe is entirely reasonable
to use a low z meter.


You are starting to sound like your hero, the cut & paste 'surge
protector W_Tom'.

Arloe can use anything he wants to. No one else cares, but a lot of
what he posts is old wives tales.

Bullshit. Prove me wrong.

It is not uncommon to read mains voltage, not some BS 83VAC like some
have referred to, but MAINS VOLTAGE on a conductor that is isolated.

When you have a panel where the active cables are segregated form the
neutrals, you can get very strong, alternating magnetic fields
depending on the current draw.

If you put an isolated cable in that field you will measure voltage on
that cable with a DMM. An electrician can not rely on reading an
"incorrect" voltage as an assurance that the cable is dead. He has to
be able to PROVE IT.
Some will use an analog meter, I don't, I use test lamps that have the
correct CAT rating for the enviroment. I follow up by testing my lamps
on a "known supply" ie. a supply that I verified live before I
performed any testing, just to prove the test lamps are functionimg as
intended.

Call it crude, I don't give a fuck, it works, it is failsafe and it is
fast.
Click to expand...

So does a screwdriver against the case, and to a buss bar, but I won't
do it.


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There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.
 
Michael A. Terrell used his keyboard to write :
Arlowe wrote:

Michael A. Terrell formulated the question :
bud-- wrote:

On Jan 27, 12:14 am, "Michael A. Terrell" <mike.terr...@earthlink.net
wrote:
bud-- wrote:

Michael A. Terrell wrote:

Is it a phantom voltage?

Easy enough to identify.

Even easier for Arloe.


Proof that its easier for him?


The appropriate tools start with a well trained brain. Otherwise,
you are a monkey throwing crap at the problem.
How fortunate that Arloe and Stewart and I are well educated and know
what we are doing.

Sure you are. Yet you can't figure out how to do it without a dumbed
down tool.

It’s the favorite nobody-knows-anything-but-Michael argument.

Not the issue, of course. Any tool can be used. The question is what
is appropriate and efficient. High z meters do not help you on power
circuits, but you can use what you want. Arloe is entirely reasonable
to use a low z meter.


You are starting to sound like your hero, the cut & paste 'surge
protector W_Tom'.

Arloe can use anything he wants to. No one else cares, but a lot of
what he posts is old wives tales.

Bullshit. Prove me wrong.

It is not uncommon to read mains voltage, not some BS 83VAC like some
have referred to, but MAINS VOLTAGE on a conductor that is isolated.

When you have a panel where the active cables are segregated form the
neutrals, you can get very strong, alternating magnetic fields
depending on the current draw.

If you put an isolated cable in that field you will measure voltage on
that cable with a DMM. An electrician can not rely on reading an
"incorrect" voltage as an assurance that the cable is dead. He has to
be able to PROVE IT.
Some will use an analog meter, I don't, I use test lamps that have the
correct CAT rating for the enviroment. I follow up by testing my lamps
on a "known supply" ie. a supply that I verified live before I
performed any testing, just to prove the test lamps are functionimg as
intended.

Call it crude, I don't give a fuck, it works, it is failsafe and it is
fast.


So does a screwdriver against the case, and to a buss bar, but I won't
do it.
Click to expand...
???????
Don't be stupid.
 
On Fri, 30 Jan 2009 08:46:30 -0800 (PST), bud-- <budnews@isp.com> wrote:

How surprising. You still have no idea what arc flash is.
Click to expand...

How NOT surprising that you are still making retarded assessments based
on ZERO facts.

You do not know a goddamned thing about what I may or may not be
familiar with.

You are a goddamned retard. You should fuck off and die... Hopefully
as the result of a huge copper vapor arc flash. Bwuahahahahaha!

Spattered... spattered... his brain's been splattered, spillin' all
over...

Goddamned google groups retards.
 
On Sat, 31 Jan 2009 09:38:44 +1100, Arlowe <bare.arsed@gmail.com> wrote:

???????
Don't be stupid.
Click to expand...

Do you means stupid, like a row of question marks is?

I have always hated little gang boy retarded punks in my news groups.

You cannot gauge stupidity from your depths of stupidity, you stupid
twit. Yes, you are deep in the barrel.
 
Archimedes' Lever wrote:
On Thu, 29 Jan 2009 10:32:34 -0800 (PST), bud-- <budnews@isp.com
wrote:

"This massive energy discharge burns the bus bars, vaporizing the
copper and thus causing an explosive volumetric increase, the arc
blast, conservatively estimated, as an expansion of 40,000 to 1. This
fiery explosion devastates everything in its path, creating deadly
shrapnel as it dissipates."


Any retarded twit that gets near power transmission lines with a
handheld meter deserves whatever he gets, regardless of the from it
takes.
Click to expand...
You really don't get what Bud's talking about.

Arc flash while working in 'low voltage' switchgear (600V or less) can be
deadly. And most electricians *do* use a handheld meter working in such
switchgear. There is no need for high-voltage probes there. Bud's not
talking about high voltage overhead transmission lines.

The very high fault currents available in such load centers can/do cause
vaporization of copper. (yes, *vaporization*, where the copper actually
changes to the gaseous state). Such load centers may have a feeder that
won't trip below 1000 amps or higher. A 'high impedance' fault such as a
sustained arc that draws several hundred amps at 600V will not trip the
feeder and so it will continue to arc for quite some time. All that power
concentrated in the confines of a load control center will vaporize a good
deal of the conductor.

Arc flash protection includes specially rated face shields that can absorb
the energy of a condensing gas cloud of copper without melting. Ordinary
plastic face shields are not allowed in such work as the heat from the
plasma gas cloud will just melt them onto your face. Similar precautions
are needed for the arc flash suit material worn.

daestrom
 
Arlowe wrote:
Michael A. Terrell used his keyboard to write :
Arlowe wrote:

Michael A. Terrell formulated the question :
bud-- wrote:

On Jan 27, 12:14 am, "Michael A. Terrell" <mike.terr...@earthlink.net
wrote:
bud-- wrote:

Michael A. Terrell wrote:

Is it a phantom voltage?

Easy enough to identify.

Even easier for Arloe.


Proof that its easier for him?


The appropriate tools start with a well trained brain. Otherwise,
you are a monkey throwing crap at the problem.
How fortunate that Arloe and Stewart and I are well educated and know
what we are doing.

Sure you are. Yet you can't figure out how to do it without a dumbed
down tool.

It’s the favorite nobody-knows-anything-but-Michael argument.

Not the issue, of course. Any tool can be used. The question is what
is appropriate and efficient. High z meters do not help you on power
circuits, but you can use what you want. Arloe is entirely reasonable
to use a low z meter.


You are starting to sound like your hero, the cut & paste 'surge
protector W_Tom'.

Arloe can use anything he wants to. No one else cares, but a lot of
what he posts is old wives tales.

Bullshit. Prove me wrong.

It is not uncommon to read mains voltage, not some BS 83VAC like some
have referred to, but MAINS VOLTAGE on a conductor that is isolated.

When you have a panel where the active cables are segregated form the
neutrals, you can get very strong, alternating magnetic fields
depending on the current draw.

If you put an isolated cable in that field you will measure voltage on
that cable with a DMM. An electrician can not rely on reading an
"incorrect" voltage as an assurance that the cable is dead. He has to
be able to PROVE IT.
Some will use an analog meter, I don't, I use test lamps that have the
correct CAT rating for the enviroment. I follow up by testing my lamps
on a "known supply" ie. a supply that I verified live before I
performed any testing, just to prove the test lamps are functionimg as
intended.

Call it crude, I don't give a fuck, it works, it is failsafe and it is
fast.


So does a screwdriver against the case, and to a buss bar, but I won't
do it.

???????
Don't be stupid.
Click to expand...

I don't want your job. You're the expert at stupid.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.
 
krw wrote:
What's wrong with using a hi Z voltmeter in a live panel? I do it
more often than I really care for, and never have a problem.

There isn't anything wrong with it. Analog meters are dead. High
impedance digital meters are only a problem if there is a loose nut
inside the panel, holding the leads.
Click to expand...
Actually it does cause false voltage readings even in circuits with no
"loose nuts". You can connect the meter to a point in the circuit that is
open somewhere, perhaps because of an open switch contact, and you get false
voltage readings that can range from 10V to close to line voltage due to
stray pickup of the wires. It causes electricians to sometimes misdiagnose
problems, and it causes confusion. I often demonstrate this to my training
classes so that they are aware of it.

This is an unavoidable and unfortunate side effect of high impedance digital
meters. You need to understand it when you use them so that you can question
and investigate readings that don't make sense.

Analog meters don't have this problem, but they are disappearing because the
analog circuits can not meet the necessary safety standards.

Ben Miller

--
Benjamin D Miller, PE
www.bmillerengineering.com
 
Ben Miller wrote:
krw wrote:

What's wrong with using a hi Z voltmeter in a live panel? I do it
more often than I really care for, and never have a problem.

There isn't anything wrong with it. Analog meters are dead. High
impedance digital meters are only a problem if there is a loose nut
inside the panel, holding the leads.

Actually it does cause false voltage readings even in circuits with no
"loose nuts". You can connect the meter to a point in the circuit that is
open somewhere, perhaps because of an open switch contact, and you get false
voltage readings that can range from 10V to close to line voltage due to
stray pickup of the wires. It causes electricians to sometimes misdiagnose
problems, and it causes confusion. I often demonstrate this to my training
classes so that they are aware of it.

This is an unavoidable and unfortunate side effect of high impedance digital
meters. You need to understand it when you use them so that you can question
and investigate readings that don't make sense.

Analog meters don't have this problem, but they are disappearing because the
analog circuits can not meet the necessary safety standards.
Click to expand...

You mean that cheap analog VOM had low impedance inputs. There were
millions of VTVM and FET input analog meters with a 10 Megaohm input
impedance in use over the years, and a lot are still in use.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.
 
In article <CpednVzKH42bXxTUnZ2dnUVZ_jadnZ2d@earthlink.com>,
Ben@somewhere says...>
krw wrote:

What's wrong with using a hi Z voltmeter in a live panel? I do it
more often than I really care for, and never have a problem.

There isn't anything wrong with it. Analog meters are dead. High
impedance digital meters are only a problem if there is a loose nut
inside the panel, holding the leads.

Actually it does cause false voltage readings even in circuits with no
"loose nuts".
Click to expand...
Of course not. The "loose nut" is the one interpreting the
measurements.

u can connect the meter to a point in the circuit that is
open somewhere, perhaps because of an open switch contact, and you get false
voltage readings that can range from 10V to close to line voltage due to
stray pickup of the wires. It causes electricians to sometimes misdiagnose
problems, and it causes confusion. I often demonstrate this to my training
classes so that they are aware of it.
Click to expand...
Right. The typical sparky is clueless. This fact has been
demonstrated here endlessly.

This is an unavoidable and unfortunate side effect of high impedance digital
meters. You need to understand it when you use them so that you can question
and investigate readings that don't make sense.
Click to expand...
It certainly may be if you're clueless.

Analog meters don't have this problem, but they are disappearing because the
analog circuits can not meet the necessary safety standards.
Click to expand...
"Analog" has nothing to do with it.
 
Michael A. Terrell wrote:
You mean that cheap analog VOM had low impedance inputs. There were
millions of VTVM and FET input analog meters with a 10 Megaohm input
impedance in use over the years, and a lot are still in use.
Click to expand...
Those are great on a lab bench, however very few were ever used for
industrial power measurements. FET inputs are not notoriously rugged,
although they could be used if desired. It is difficult to run an extension
cord for a VTVM out on a factory floor, not to mention the smoke that can
escape when you apply a grounded test lead on a power system measurement,
assuming that you survive to talk about it :-(

You will not find very many analog meters with an IEC CAT rating, with good
reason. The typical analog industrial meters such as the Amprobe RS series
or the Simpson 260 series have resistor networks on the inputs, and very
likely don't have the requisite creep and clearance distances in their
construction. There are also problems with the Ohms circuits. One of the IEC
requirements is that you can safely apply maximum rated voltage (ie. 600 or
1000 volts for example) to the meter inputs with the range and mode switches
set to any setting. The meter doesn't need to continue working, just fail
safely or do nothing. Many meters have fuses for the amp ranges, but analog
ohms circuits can fail catastrophically if high voltages are applied to
them. The manufacturers just can not justify the redesign of those meters to
meet the safety standards.

Ben Miller


--
Benjamin D Miller, PE
www.bmillerengineering.com
 
User Group

You better pray user Roy comes back safe from his ice fishing trip
without him the group is a pathetic rapidly decaying lounge for Trolls
and Terrorists
and apprebtly whiney connected faggots

I cannot protect you from yourselves
you need him more than you can begin to imagine
if any harm should become him there will be hell to pay
I mean ANY harm you Troll Infested Group of losers.

I Am Proteus
 
On Wed, 04 Feb 2009 12:08:12 -0500, "Michael A. Terrell"
<mike.terrell@earthlink.net> wrote:

You mean that cheap analog VOM had low impedance inputs. There were
millions of VTVM and FET input analog meters with a 10 Megaohm input
impedance in use over the years, and a lot are still in use.
Click to expand...

AND they worked fine for the purpose being discussed and still do.
 
On Wed, 4 Feb 2009 16:04:49 -0600, "Ben Miller" <Ben@somewhere> wrote:

however very few were ever used for
industrial power measurements.
Click to expand...

Bwuahahahahaha! I just love made up statistics.

Your true colors are showing.

I know you are smart, but this bolstering of your OPINION bullshit is
just that and nothing more.
 
Archimedes' Lever wrote:
On Wed, 4 Feb 2009 16:04:49 -0600, "Ben Miller" <Ben@somewhere> wrote:

however very few were ever used for
industrial power measurements.


Bwuahahahahaha! I just love made up statistics.

Your true colors are showing.

I know you are smart, but this bolstering of your OPINION bullshit is
just that and nothing more.
Click to expand...
No bolstering of anything and no statistics. This is based on personal
observation.. I have seen electricians of all ages using many types of
meters, from wiggy's to amprobes to Radio Shack digitals to high end Flukes.
I have NEVER seen any of them carrying around a VTVM and an extension cord
to power it! It is completely wrong for industrial measurements, not to
mention unsafe. Explain, for example, how you would measure line-line on a
480 volt three-phase system, with a VTVM that has a grounded probe (yeah, I
know, a three-prong adapter and a piece of cardboard to isolate the meter
enclosure.)

I won't say the same thing about FET input meters, as there might be some
used. I just have not seen any. Since they are battery powered, they at
least have isolated leads.

We have electricians on this group. Let's see what they say.

Ben Miller

--
Benjamin D Miller, PE
www.bmillerengineering.com
 
Ben Miller wrote:
Michael A. Terrell wrote:
You mean that cheap analog VOM had low impedance inputs. There were
millions of VTVM and FET input analog meters with a 10 Megaohm input
impedance in use over the years, and a lot are still in use.

Those are great on a lab bench, however very few were ever used for
industrial power measurements. FET inputs are not notoriously rugged,
although they could be used if desired. It is difficult to run an extension
cord for a VTVM out on a factory floor, not to mention the smoke that can
escape when you apply a grounded test lead on a power system measurement,
assuming that you survive to talk about it :-(
Click to expand...

Some VTVM had a built in battery for portable use. They were rare,
but they existed. They used subminiature tubes with a 1.5 or 3 volt
filament like those in early hearing aids.


You will not find very many analog meters with an IEC CAT rating, with good
reason. The typical analog industrial meters such as the Amprobe RS series
or the Simpson 260 series have resistor networks on the inputs, and very
likely don't have the requisite creep and clearance distances in their
construction. There are also problems with the Ohms circuits. One of the IEC
requirements is that you can safely apply maximum rated voltage (ie. 600 or
1000 volts for example) to the meter inputs with the range and mode switches
set to any setting. The meter doesn't need to continue working, just fail
safely or do nothing. Many meters have fuses for the amp ranges, but analog
ohms circuits can fail catastrophically if high voltages are applied to
them. The manufacturers just can not justify the redesign of those meters to
meet the safety standards.
Click to expand...

The 260 is a dinosaur, over price instrument in today's work
environment. Even if it was modified and certified, it would be sold to
a niche market and not worth the engineering costs.

The early FET input analog meters I've used would die if their was a
tiny spark when probing. If they had a small choke on the input to
filter the RF, they were fine, but it would void the certification.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.
 
On Wed, 4 Feb 2009 20:03:00 -0600, "Ben Miller" <Ben@somewhere> wrote:

I have NEVER seen any of them carrying around a VTVM and an extension cord
to power it!
Click to expand...

NOBODY said a goddamned thing about an AC powered device. Other than
YOU.
 
On Wed, 4 Feb 2009 20:03:00 -0600, "Ben Miller" <Ben@somewhere> wrote:

I have NEVER seen any of them carrying around a VTVM and an extension cord
to power it!
Click to expand...

I have seen VTVMs powered by old B+ batteries, as in a 63 Volt source.

Just to depose what I know was going to be your "You don't even know
what a VTVM is!" CRAP, before it even starts.
 
Archimedes' Lever wrote:
On Wed, 4 Feb 2009 20:03:00 -0600, "Ben Miller" <Ben@somewhere> wrote:

I have NEVER seen any of them carrying around a VTVM and an
extension cord to power it!


I have seen VTVMs powered by old B+ batteries, as in a 63 Volt
source.
Click to expand...

I am not denying that. I am just saying I have never seen an electrician
with one.


Just to depose what I know was going to be your "You don't even know
what a VTVM is!" CRAP, before it even starts.
Click to expand...

Hey, give me little credit. We have both been on this group for awhile, and
I am aware of your electronics background.


Ben Miller

--
Benjamin D Miller, PE
www.bmillerengineering.com
 
"Arlowe" <bare.arsed@gmail.com> wrote in message
news:mn.baf47d913b19e461.90583@gmail.com...
Archimedes' Lever brought next idea :
On Thu, 22 Jan 2009 17:28:17 +0000 (GMT), Stuart <Spambin@argonet.co.uk
wrote:

In article <mn.b4a77d91b151170f.90583@gmail.com>,
Arlowe <bare.arsed@gmail.com> wrote:

I don't test for live circuits with a DMM.
I use test lamps or a low(er) impedance voltmeter.
If you worked for me I would sack your arse if I caught you using a DMM
to test for live.

Nice to know someone round here knows what they are doing!


Both of you are idiotic to think that there is some inherent error or
danger in using a DMM to observe an AC line.

You are an idiot if you can not see the potential for error.
If you have multiple conductors carrying current nearby you will read
voltage on an isolated circuit with a DMM. That voltage will not be read
on an analoge meter or with a resistive voltage indicating device like
test lamps.

I can see that none of you ever worked inside high energy panels.

I will try and explain it another way.
voltmeters on DMMs are good for measuring the difference in potential,
but they are not suitable for checking for the presence of a difference in
potential inside a changing magnetic field.

Now if you can not see why I say it is not good practice to test for live
circuits with a DMM you DO NOT KNOW ANYTHING ABOUT THE GENERATION OF
ELECTRICITY.

I am finished discussing this.
Click to expand...
What you're discribing is call phantom voltage; It's a result of capacitance
between conductors. The high input impeadance (10 MOhms) of a DMM can cause
you to get a reading on a conductor if it is in close proximity to another
live conductor. Wires running along inside of a conduit will have high
capacitance because the wire you are testing and live wires are running
parallel to eachother over a long distance.

Shaun
 
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