Oscilloscopes - to gound or not ....

[budgie]

Yep, that perennial question. Not a troll. I'm fixing up an old scope at the
moment, and the owner asked me for my view.

For me, it's a bit like ME working on live equipment (which I wind up doing
quite often, as the most practical way of proceeding). It's a case of MY risk
evaluation each time the situation arises. In some situations the risk is
acceptable IMOO, but I can't recommend others take that same course of action.
Not hypocrisy, just that I can't assess the risk for them and I don't know how
they handle their own safety in such situations.

Recently I had to sort out the electronic ignition module on a gas wall oven.
Neg rail was tied to neutral, so a grounded CRO chassis/probe_return was a PITA
because I was looking for Vbe-sized signals with several volts of 50Hz present.
I had to choose between lifting the ground or using differential mode and
reducing to a single channel. On that occasion I went differential.

I have seen two different arrangements used to unground CROs. One is a switch
located on the rear panel, which is in series with the incoming earth conductor.
Highly illegal and dangerous from the pov that it doesn't shout "unearthed" and
can be overlooked. The second used a short two-core lead (sans earth) in series
with the instrument lead. Also dodgy.

So to the question. What do the rest of you do/think?

 

[Phil Allison]

"budgie" <me@privacy.net> wrote in message
news:00hkr0t04vlqcv2cukhblpc9i1r6oadl5f@4ax.com...

Yep, that perennial question. Not a troll. I'm fixing up an old scope at
the
moment, and the owner asked me for my view.

For me, it's a bit like ME working on live equipment (which I wind up
doing
quite often, as the most practical way of proceeding). It's a case of MY
risk
evaluation each time the situation arises. In some situations the risk is
acceptable IMOO, but I can't recommend others take that same course of
action.
Not hypocrisy, just that I can't assess the risk for them and I don't know
how
they handle their own safety in such situations.

Recently I had to sort out the electronic ignition module on a gas wall
oven.
Neg rail was tied to neutral, so a grounded CRO chassis/probe_return was a
PITA
because I was looking for Vbe-sized signals with several volts of 50Hz
present.
I had to choose between lifting the ground or using differential mode and
reducing to a single channel. On that occasion I went differential.

I have seen two different arrangements used to unground CROs. One is a
switch
located on the rear panel, which is in series with the incoming earth
conductor.
Highly illegal and dangerous from the pov that it doesn't shout
"unearthed" and
can be overlooked. The second used a short two-core lead (sans earth) in
series
with the instrument lead. Also dodgy.

So to the question. What do the rest of you do/think?

** Have you never seen a battery operated, portable CRO ?? I don't mean the
all insulated, plastic hand held LCD ones - but normal CROs with metal
cases and standard BNC connectors. It is very easy of the whole caboodle to
become live at some dangerous voltage and entirely up to the operator to be
aware of that possibility.

Test equipment is exempt from compliance with electrical safety standards
(or EMC regs ) that apply to most appliances -however most AC powered CROs
have the metalwork earthed since this is the usual practice and to do
otherwise would leave the maker open to a claim of negligence. Some CROs
( eg BWD 804) have a removable link to allow the electronics to float while
the case remains grounded - so only the connectors are potentially hot.

My present bench CRO has a 22 ohm resistor in series with the AC ground
conductor BYPASSED with a 20 amp bridge rectifier wired as inverse parallel
diodes - in case of contact with the AC active. This is enough series
resistance to eliminate ground loop hums in audio / video testing. As long
as there is no ELCB in the circuit, this could be used to make measurements
with the neutral used as reference.



.............. Phil

 

[CBarn24050]

Not much excuse for doing it with battery powered hand held scopes we have
these days. I allways use differential probes, I'm getting to the age where 1
more shock could be my last.

 

[John Tserkezis]

budgie wrote:

So to the question. What do the rest of you do/think?

We used to routinely unearth cros, but in the past 6-7 years, I've only
worked on low power, low voltage battery powered or otherwise isolated
equipment, so it hasn't been an issue for me.

If the need arose, I'd do it again. Though this time I might actually mark
the front of the cro with some clear visible sign signifiying as such. Perhaps
I'm getting older and not quite as invincible as I used to be.

--
Linux Registered User # 302622 <http://counter.li.org>

 

[John Crighton]

On Sat, 11 Dec 2004 09:04:51 +0800, budgie <me@privacy.net> wrote:

I have seen two different arrangements used to unground CROs. One is a switch
located on the rear panel, which is in series with the incoming earth conductor.
Highly illegal and dangerous from the pov that it doesn't shout "unearthed" and
can be overlooked. The second used a short two-core lead (sans earth) in series
with the instrument lead. Also dodgy.

So to the question. What do the rest of you do/think?

Hello Budgie,
I bought an old Tektronix 454 several months ago and to my surprise
there is a switch on the rear panel which disconnects the earth lead
in the power cord. If its good enough for Tektronix to do that, I now,
no longer have the guilts about my past practice of isolating the
earth wire in the power cord of other old CROs with banana plug
and socket. Just thinking about it now, I should have made a better
job of it with a mounted switch. Some lazy fellow technicians just
hacksawed the earth pin off the plug and didn't bother to replace
it when doing urgent field service work.

Some techs use a 240V to 240V mains isolating transformer.
That is a bit better than just opening up the earth lead.
With no earth lead the metal work on the front panal floats
somewhere between active and neutral if little noise suppression
capacitors are fitted from active to chassis and neutral to chassis.
Sometimes you can get a little annoying tingle (mild shock) when
touching the front panel metal work of the CRO.

When I was working at AWA at Leichardt twenty years ago, the
service department there couldn't afford a proper battery powered
CRO so one of the chaps in the workshop modified a little Philips
10 or 15 MHz CRO to run off 24V battery power. From being an
old CRO that nobody bothered to use, it suddenly became very
popular in its modified form to take out on field service work.

I have been looking for one of these old Philips CROs for a while
now, for the express purpose of modifying it the same way and
using it for the type of measurements you were making Budgie.
I have missed out a couple of times at trash and treasure markets
and ham field days where they have been sold for $20 to $50.
What I am leading up to tell you Budgie, is this modified Philips
CRO is very economical on batteries. I just wish I could remember
the model number for you. PM??? About the size of a Besser
block, two tone grey with a plastic rear panel compartment for
probes and hand book.

Regards
John Crighton
Hornsby

 

[Dennis Nolan]

Phil Allison wrote:

"budgie" <me@privacy.net> wrote in message
news:00hkr0t04vlqcv2cukhblpc9i1r6oadl5f@4ax.com...

Yep, that perennial question. Not a troll. I'm fixing up an old scope at
the
moment, and the owner asked me for my view.

For me, it's a bit like ME working on live equipment (which I wind up
doing
quite often, as the most practical way of proceeding). It's a case of MY
risk
evaluation each time the situation arises. In some situations the risk is
acceptable IMOO, but I can't recommend others take that same course of
action.
Not hypocrisy, just that I can't assess the risk for them and I don't know
how
they handle their own safety in such situations.

Recently I had to sort out the electronic ignition module on a gas wall
oven.
Neg rail was tied to neutral, so a grounded CRO chassis/probe_return was a
PITA
because I was looking for Vbe-sized signals with several volts of 50Hz
present.
I had to choose between lifting the ground or using differential mode and
reducing to a single channel. On that occasion I went differential.

I have seen two different arrangements used to unground CROs. One is a
switch
located on the rear panel, which is in series with the incoming earth
conductor.
Highly illegal and dangerous from the pov that it doesn't shout
"unearthed" and
can be overlooked. The second used a short two-core lead (sans earth) in
series
with the instrument lead. Also dodgy.

So to the question. What do the rest of you do/think?




** Have you never seen a battery operated, portable CRO ?? I don't mean the
all insulated, plastic hand held LCD ones - but normal CROs with metal
cases and standard BNC connectors. It is very easy of the whole caboodle to
become live at some dangerous voltage and entirely up to the operator to be
aware of that possibility.

Test equipment is exempt from compliance with electrical safety standards
As I recall(though the number may be wrong, I'm relying on my memory),

the relevent standard is AS-NZS 6720 :2003 In-service safety testing of
electrical appliemces.
But I can't seem to recall any exemptions in it for test equipment

(or EMC regs ) that apply to most appliances -however most AC powered CROs
have the metalwork earthed since this is the usual practice and to do
otherwise would leave the maker open to a claim of negligence.
Actualy it would contrivine the current wireing standards.

Some CROs

( eg BWD 804) have a removable link to allow the electronics to float while
the case remains grounded - so only the connectors are potentially hot.

I don't know the model 804, but as far as I know BWD and McVann have

never had complience approval on any of their products, so immitating
their practices is not very smart.
Last week I received a McVann 604 Minilab in for repair. When I removed
the cover I was appaled at the 240V electrical wireing. Uninsulated 240V
wiring just waiting for some unlucky tech to put their finger on. You
don't realy expect that sort of thing in current equipment. On Monday I
will finish writing the report to the OCEI about it.

My present bench CRO has a 22 ohm resistor in series with the AC ground
conductor BYPASSED with a 20 amp bridge rectifier wired as inverse parallel
diodes - in case of contact with the AC active. This is enough series
resistance to eliminate ground loop hums in audio / video testing. As long
as there is no ELCB in the circuit, this could be used to make measurements
with the neutral used as reference.

My work benches have ELCBs and isolation transformers.

Also all electrical equipment is electrical safety tested before being
repaired.

Have a good day
Dennis.

 

[Phil Allison]

"Dennis Nolan"
Phil Allison

** Have you never seen a battery operated, portable CRO ?? I don't mean
the all insulated, plastic hand held LCD ones - but normal CROs with
metal cases and standard BNC connectors. It is very easy of the whole
caboodle to become live at some dangerous voltage and entirely up to the
operator to be aware of that possibility.

Test equipment is exempt from compliance with electrical safety
standards

As I recall(though the number may be wrong, I'm relying on my memory), the
relevent standard is AS-NZS 6720 :2003 In-service safety testing of
electrical appliemces.

** Got SFA to do with items of test equipment themselves.

But I can't seem to recall any exemptions in it for test equipment

** Yawn.....

(or EMC regs ) that apply to most appliances -however most AC powered
CROs have the metalwork earthed since this is the usual practice and to
do otherwise would leave the maker open to a claim of negligence.


Actualy it would contrivine the current wireing standards.

** Which do NOT apply to items of test equipment.

Some CROs
( eg BWD 804) have a removable link to allow the electronics to float
while the case remains grounded - so only the connectors are potentially
hot.


I don't know the model 804, but as far as I know BWD and McVann have never
had complience approval on any of their products, so immitating their
practices is not very smart.

** Approval is not required for test equipment - you are just *not*
getting this.

Last week I received a McVann 604 Minilab in for repair. When I removed
the cover I was appaled at the 240V electrical wireing. Uninsulated 240V
wiring just waiting for some unlucky tech to put their finger on. You
don't realy expect that sort of thing in current equipment.

** Boo hoo - oodles of exposed high voltage contact points ** inside
*** nearly everything I service.

On Monday I> will finish writing the report to the OCEI about it.

** What a posturing PITA prick you are.

My present bench CRO has a 22 ohm resistor in series with the AC ground
conductor BYPASSED with a 20 amp bridge rectifier wired as inverse
parallel diodes - in case of contact with the AC active. This is
enough series resistance to eliminate ground loop hums in audio / video
testing. As long as there is no ELCB in the circuit, this could be used
to make measurements with the neutral used as reference.

My work benches have ELCBs and isolation transformers.

** Does nothing for ground loop hums - you fucking dimwit.

Also all electrical equipment is electrical safety tested before being
repaired.

** Inspect all your stools for worms and maggots as well ????

Use a micoscope ???



.............. Phil

 

[KLR]

On Sat, 11 Dec 2004 08:11:31 GMT, john_c@tpg.com.au (John Crighton)
wrote:

On Sat, 11 Dec 2004 09:04:51 +0800, budgie <me@privacy.net> wrote:


I have seen two different arrangements used to unground CROs. One is a switch
located on the rear panel, which is in series with the incoming earth conductor.
Highly illegal and dangerous from the pov that it doesn't shout "unearthed" and
can be overlooked. The second used a short two-core lead (sans earth) in series
with the instrument lead. Also dodgy.

So to the question. What do the rest of you do/think?

Hello Budgie,
I bought an old Tektronix 454 several months ago and to my surprise
there is a switch on the rear panel which disconnects the earth lead
in the power cord. If its good enough for Tektronix to do that, I now,
no longer have the guilts about my past practice of isolating the
earth wire in the power cord of other old CROs with banana plug
and socket. Just thinking about it now, I should have made a better
job of it with a mounted switch. Some lazy fellow technicians just
hacksawed the earth pin off the plug and didn't bother to replace
it when doing urgent field service work.

Some techs use a 240V to 240V mains isolating transformer.
That is a bit better than just opening up the earth lead.
With no earth lead the metal work on the front panal floats
somewhere between active and neutral if little noise suppression
capacitors are fitted from active to chassis and neutral to chassis.
Sometimes you can get a little annoying tingle (mild shock) when
touching the front panel metal work of the CRO.

One method I have used for test gear where earth isolation may be

needed (also works great with soldering stations etc where you DON'T
want an earthed iron tip, or bench power supplies) is to mount an
illuminated rocker (or whatever) switch on the front panel of the
unit, and use 1 pole of it to cut the earth wire to the mains, and use
the other pole to turn on a warning light/neon in the switch body to
show a clear warning that THE EARTH IS OFF and to act accordingly.

(Of course the switch should be 250v 10A rated and of a design and in
a location that isn't easy to activate it accidentally)

Another (probably better) method was to use a Bi-colour LED (or 2

LEDS) that glow GREEN when the earth is connected and RED when the
earth is off. Having it flash when red may also be a good idea -
though we didnt do this.

These can usually be powered from the existing low voltage power

supply in the unit - and switched via the second pole of the switch
used to switch the earth wire.

With the soldering station - we only disconnected the earth to the

iron tip with the switch - not the earth to the case or the
transformer inside - as there was no need.
Scopes and power supplies however are a different discussion
altogether, and depend a lot on what exactly you are measuring or
powering.

-------------------------------

Of course - only experienced people who know EXACTLY what they are
doing, who know about earthing, how the mains system works - and how
the equipment under test works is powered, and of course electrical
safety - should be doing mods or using modded equipment such as this.

 

[Dennis Nolan]

Phil Allison wrote:

"Dennis Nolan"
Phil Allison

** Have you never seen a battery operated, portable CRO ?? I don't mean
the all insulated, plastic hand held LCD ones - but normal CROs with
metal cases and standard BNC connectors. It is very easy of the whole
caboodle to become live at some dangerous voltage and entirely up to the
operator to be aware of that possibility.

Test equipment is exempt from compliance with electrical safety
standards

As I recall(though the number may be wrong, I'm relying on my memory), the
relevent standard is AS-NZS 6720 :2003 In-service safety testing of
electrical appliemces.



** Got SFA to do with items of test equipment themselves.



But I can't seem to recall any exemptions in it for test equipment



** Yawn.....




(or EMC regs ) that apply to most appliances -however most AC powered
CROs have the metalwork earthed since this is the usual practice and to
do otherwise would leave the maker open to a claim of negligence.


Actualy it would contrivine the current wireing standards.



** Which do NOT apply to items of test equipment.




Some CROs

( eg BWD 804) have a removable link to allow the electronics to float
while the case remains grounded - so only the connectors are potentially
hot.



I don't know the model 804, but as far as I know BWD and McVann have never
had complience approval on any of their products, so immitating their
practices is not very smart.



** Approval is not required for test equipment - you are just *not*
getting this.



Last week I received a McVann 604 Minilab in for repair. When I removed
the cover I was appaled at the 240V electrical wireing. Uninsulated 240V
wiring just waiting for some unlucky tech to put their finger on. You
don't realy expect that sort of thing in current equipment.



** Boo hoo - oodles of exposed high voltage contact points ** inside
*** nearly everything I service.




On Monday I> will finish writing the report to the OCEI about it.



** What a posturing PITA prick you are.



My present bench CRO has a 22 ohm resistor in series with the AC ground
conductor BYPASSED with a 20 amp bridge rectifier wired as inverse
parallel diodes - in case of contact with the AC active. This is
enough series resistance to eliminate ground loop hums in audio / video
testing. As long as there is no ELCB in the circuit, this could be used
to make measurements with the neutral used as reference.


My work benches have ELCBs and isolation transformers.



** Does nothing for ground loop hums - you fucking dimwit.



Also all electrical equipment is electrical safety tested before being
repaired.




** Inspect all your stools for worms and maggots as well ????

Use a micoscope ???



............. Phil



Two years at Sydney University?

You stated "Test equipment is exempt from compliance with electrical
safety standards" I disagreed and cited as a basis of my disagreement
the relevant Australian standard that my opinion is based upon.
From a former Sydney University student I expected the reply to contain
a reference to an Australian standard where test equipment is granted
relief from the normal electrical safety standards. To me, your reply
indicates that you are unfamiliar with the current Australian Standards.


As I mentioned yesterday, I cited from memory. This morning I checked
and the correct reference is
AS/NZS 3760: 2003
In-service safety inspection and testing of electrical equipment.

Furthermore the minimum standards for all electrical equipment other
than electrical toys is defined in AS/NZS 3820: 1998 clauses 4.1, 4.2
and 4.3.

And according to the Electrical Safety Act 1998 (Act No. 25/1998)
the definition of
"Electrical equipment" means any appliance, wire, fitting, cable,
conduit or apparatus that generates, uses, conveys or controls (or that
is intended to generate, use, convey or control) electricity.

To me the above would include all electrical equipment.

Have a nice day
Dennis.

 

[Mike Harding]

On Sat, 11 Dec 2004 09:04:51 +0800, budgie <me@privacy.net> wrote:

Yep, that perennial question. Not a troll. I'm fixing up an old scope at the
moment, and the owner asked me for my view.

snip

For years I always use to snip the earth on my scopes, then about
8 or 9 years ago I bought a new Tek with a moulded lead and
never got around to removing the earth. Once or twice it's been
a minor hindrance but nothing more - if needs arise I will do
it again without any qualms. One technique I saw which I quite
liked was the earth lead was looped a couple of inches outside
the plug and cut - a male/female push terminal was fitted to the
earth lead and could easily be connected/disconnected and
it was pretty obvious when it was not connected, providing the
plug was in sight, of course.

I'm not sure I fully understood your post but if you were asking
should you do this for someone else them my answer would
be a big _NO_. If they don't understand things enough to do it
themselves then they should not be working on medium
voltages and especially not on unearthed stuff.

Mike Harding

 

[Phil Allison]

"Dennis Nolan"

Phil Allison wrote:

** Have you never seen a battery operated, portable CRO ?? I don't mean
the all insulated, plastic hand held LCD ones - but normal CROs with
metal cases and standard BNC connectors. It is very easy of the whole
caboodle to become live at some dangerous voltage and entirely up to the
operator to be aware of that possibility.

Test equipment is exempt from compliance with electrical safety
standards

As I recall(though the number may be wrong, I'm relying on my memory),
the relevent standard is AS-NZS 6720 :2003 In-service safety testing of
electrical appliemces.



** Got SFA to do with items of test equipment themselves.



But I can't seem to recall any exemptions in it for test equipment



** Yawn.....




(or EMC regs ) that apply to most appliances -however most AC powered
CROs have the metalwork earthed since this is the usual practice and to
do otherwise would leave the maker open to a claim of negligence.


Actualy it would contrivine the current wireing standards.



** Which do NOT apply to items of test equipment.




Some CROs

( eg BWD 804) have a removable link to allow the electronics to float
while the case remains grounded - so only the connectors are
potentially hot.



I don't know the model 804, but as far as I know BWD and McVann have
never had complience approval on any of their products, so immitating
their practices is not very smart.



** Approval is not required for test equipment - you are just *not*
getting this.



Last week I received a McVann 604 Minilab in for repair. When I removed
the cover I was appaled at the 240V electrical wireing. Uninsulated 240V
wiring just waiting for some unlucky tech to put their finger on. You
don't realy expect that sort of thing in current equipment.



** Boo hoo - oodles of exposed high voltage contact points **
inside *** nearly everything I service.


On Monday I will finish writing the report to the OCEI about it.


** What a posturing PITA prick you are.


My present bench CRO has a 22 ohm resistor in series with the AC
ground conductor BYPASSED with a 20 amp bridge rectifier wired as
inverse parallel diodes - in case of contact with the AC active.
This is enough series resistance to eliminate ground loop hums in
audio / video testing. As long as there is no ELCB in the circuit,
this could be used to make measurements with the neutral used as
reference.


My work benches have ELCBs and isolation transformers.



** Does nothing for ground loop hums - you fucking dimwit.



You stated "Test equipment is exempt from compliance with electrical
safety standards" I disagreed and cited as a basis of my disagreement the
relevant Australian standard that my opinion is based upon.

** The exemption is not in there.

From a former Sydney University student I expected the reply to contain a
reference to an Australian standard ....

** Proves you have neve been near any university.

where test equipment is granted relief from the normal electrical safety
standards.

** No need for the exemption to be in any standard - you fool.

To me, your reply indicates that you are unfamiliar with the current
Australian Standards.

** To me - your whole attitude indicates that you are an anal fuckwit.

As I mentioned yesterday, I cited from memory. This morning I checked and
the correct reference is
AS/NZS 3760: 2003
In-service safety inspection and testing of electrical equipment.

Furthermore the minimum standards for all electrical equipment other than
electrical toys is defined in AS/NZS 3820: 1998 clauses 4.1, 4.2 and 4.3.

And according to the Electrical Safety Act 1998 (Act No. 25/1998)
the definition of
"Electrical equipment" means any appliance, wire, fitting, cable, conduit
or apparatus that generates, uses, conveys or controls (or that is
intended to generate, use, convey or control) electricity.

To me the above would include all electrical equipment.

** I suppose it would NEVER dawn on a colossal FUCKWIT like you Nolan to
simply ask me the source of info about the exemption for items of test gear
???

Hint - try phoning the relevant office in charge of safety approvals.

I suppose it would NEVER dawn on a colossal FUCKWIT like you Nolan how
anyone can sell a bench power supply that has an output voltage of over 100
volts DC at several amps ??

I suppose it would NEVER dawn on a colossal FUCKWIT like you Nolan that
test equipment is not used by or sold to ordinary members of the public.



BTW1 Bottom posting dumb speeches ( while ignoring everything the other
poster has said ) is just as bad as top posting them.

BTW2 Your spelling is atrocious.





................ Phil

 

[Phil Allison]

"Dennis Nolan"

My work benches have ELCBs and isolation transformers.

** Never occur to you that the using latter defeats the life saving effect
of the former ???

Also all electrical equipment is electrical safety tested before being
repaired.

** How ambiguous - does that mean doing useless PAT tests ???

Does "electrical equipment" mean plug in appliances ???

Is PAT testing done AFTER repairs as well ???

Do all the needed visual inspections too ?


BTW Ever check the wire gauge being used in IEC leads ???





............ Phil

 

[Dennis Nolan]

Phil Allison wrote:

"Dennis Nolan"

Phil Allison wrote:

** Have you never seen a battery operated, portable CRO ?? I don't mean
the all insulated, plastic hand held LCD ones - but normal CROs with
metal cases and standard BNC connectors. It is very easy of the whole
caboodle to become live at some dangerous voltage and entirely up to the
operator to be aware of that possibility.

Test equipment is exempt from compliance with electrical safety
standards

As I recall(though the number may be wrong, I'm relying on my memory),
the relevent standard is AS-NZS 6720 :2003 In-service safety testing of
electrical appliemces.



** Got SFA to do with items of test equipment themselves.




But I can't seem to recall any exemptions in it for test equipment



** Yawn.....





(or EMC regs ) that apply to most appliances -however most AC powered
CROs have the metalwork earthed since this is the usual practice and to
do otherwise would leave the maker open to a claim of negligence.


Actualy it would contrivine the current wireing standards.



** Which do NOT apply to items of test equipment.





Some CROs


( eg BWD 804) have a removable link to allow the electronics to float
while the case remains grounded - so only the connectors are
potentially hot.



I don't know the model 804, but as far as I know BWD and McVann have
never had complience approval on any of their products, so immitating
their practices is not very smart.



** Approval is not required for test equipment - you are just *not*
getting this.




Last week I received a McVann 604 Minilab in for repair. When I removed
the cover I was appaled at the 240V electrical wireing. Uninsulated 240V
wiring just waiting for some unlucky tech to put their finger on. You
don't realy expect that sort of thing in current equipment.



** Boo hoo - oodles of exposed high voltage contact points **
inside *** nearly everything I service.



On Monday I will finish writing the report to the OCEI about it.


** What a posturing PITA prick you are.



My present bench CRO has a 22 ohm resistor in series with the AC
ground conductor BYPASSED with a 20 amp bridge rectifier wired as
inverse parallel diodes - in case of contact with the AC active.
This is enough series resistance to eliminate ground loop hums in
audio / video testing. As long as there is no ELCB in the circuit,
this could be used to make measurements with the neutral used as
reference.


My work benches have ELCBs and isolation transformers.



** Does nothing for ground loop hums - you fucking dimwit.



You stated "Test equipment is exempt from compliance with electrical
safety standards" I disagreed and cited as a basis of my disagreement the
relevant Australian standard that my opinion is based upon.



** The exemption is not in there.



From a former Sydney University student I expected the reply to contain a
reference to an Australian standard ....



** Proves you have neve been near any university.



where test equipment is granted relief from the normal electrical safety
standards.



** No need for the exemption to be in any standard - you fool.



To me, your reply indicates that you are unfamiliar with the current
Australian Standards.



** To me - your whole attitude indicates that you are an anal fuckwit.




As I mentioned yesterday, I cited from memory. This morning I checked and
the correct reference is
AS/NZS 3760: 2003
In-service safety inspection and testing of electrical equipment.

Furthermore the minimum standards for all electrical equipment other than
electrical toys is defined in AS/NZS 3820: 1998 clauses 4.1, 4.2 and 4.3.

And according to the Electrical Safety Act 1998 (Act No. 25/1998)
the definition of
"Electrical equipment" means any appliance, wire, fitting, cable, conduit
or apparatus that generates, uses, conveys or controls (or that is
intended to generate, use, convey or control) electricity.

To me the above would include all electrical equipment.




** I suppose it would NEVER dawn on a colossal FUCKWIT like you Nolan to
simply ask me the source of info about the exemption for items of test gear
???
Well you cited the Australian Standards, I just wanted to know which one.

Hint - try phoning the relevant office in charge of safety approvals.

The Office of the Chief Electrical Inspector.
I suppose it would NEVER dawn on a colossal FUCKWIT like you Nolan how
anyone can sell a bench power supply that has an output voltage of over 100
volts DC at several amps ??

I suppose it would NEVER dawn on a colossal FUCKWIT like you Nolan that
test equipment is not used by or sold to ordinary members of the public.

So if my wife, or granddaughter went into Dick Smiths they would refuse

to sell her their 20MHz Oscilloscope (Cat Q1802).
Of course they wouldn't

BTW1 Bottom posting dumb speeches ( while ignoring everything the other
poster has said ) is just as bad as top posting them.

I let profanity be it's own comment.

BTW2 Your spelling is atrocious.


I've all ways noticed that good spellers make lousy servicemen.



............... Phil



Have a nice day

Dennis.

 

[Dennis Nolan]

Phil Allison wrote:

"Dennis Nolan"

My work benches have ELCBs and isolation transformers.



** Never occur to you that the using latter defeats the life saving effect
of the former ???



Also all electrical equipment is electrical safety tested before being
repaired.




** How ambiguous - does that mean doing useless PAT tests ???
No safety testing is useless. All incoming equipment is safety tested

IAW AS/NZS 3760:2003

Does "electrical equipment" mean plug in appliances ???
That's right

Is PAT testing done AFTER repairs as well ???

Yes.
Do all the needed visual inspections too ?
All part of the testing


BTW Ever check the wire gauge being used in IEC leads ???
No, if it hasn't got an approval No. on it, it is chopped up and goes

into the rubbish bin.

........... Phil




Phil, please tell me where it is decreed that test equipment does not

need safety testing, I really want to know. Because since the beginning
of October I have tested over 500 items of test equipment. This includes
Oscilloscopes, Function Generators, Signal Generators, Counter Timers
and power supplies.
The Department of Defense seem to think that their test equipment needs
safety testing.
So when you come good with the information, I can refer the Defense
Department personal to it and get on with my other work.

Have a nice day.
Dennis.

 

[Phil Allison]

"Dennis Nolan"
Phil Alison

I suppose it would NEVER dawn on a colossal FUCKWIT like you Nolan how
anyone can sell a bench power supply that has an output voltage of over
100 volts DC at several amps ??

I suppose it would NEVER dawn on a colossal FUCKWIT like you Nolan
that test equipment is not used by or sold to ordinary members of the
public.

So if my wife, or granddaughter went into Dick Smiths they would refuse to
sell her their 20MHz Oscilloscope (Cat Q1802).
Of course they wouldn't

** DSE scopes have no safety risks since they are sold fully earthed.

That was as ass of a point.

BTW1 Bottom posting dumb speeches ( while ignoring everything the
other poster has said ) is just as bad as top posting them.

I let profanity be it's own comment.

** You let your stupid arse do far too much talking.

BTW2 Your spelling is atrocious.


I've all ways noticed that good spellers make lousy servicemen.

** Shame you cannot tell shit from chocolate .




............. Phil

 

[Phil Allison]

"Dennis Nolan"

Phil Allison wrote:

My work benches have ELCBs and isolation transformers.


** Never occur to you that the using latter defeats the life saving
effect of the former ???

** Look - no answer ????

BTW Ever check the wire gauge being used in IEC leads ???

No, if it hasn't got an approval No. on it, it is chopped up and goes into
the rubbish bin.

** Those approval numbers might be faked - the Chinese do that you know.

We had a long thread about it here a while ago - the WA safety inspectors
took it real seriously.

Phil, please tell me where it is decreed that test equipment does not need
safety testing, I really want to know.

** That is not any claim that I made.

You *DO* have a serious reading comprehension problem.

Here is what I wrote again :

" Test equipment is exempt from compliance with electrical safety standards
(or EMC regs ) that apply to most appliances... "

This is exactly as said to me by the electrical safety branch of Fair
Trading, here in Sydney, when I enquired about any approvals needed for my
"RMS Current Monitor " - published in Electronics Australia magazine in Jan
1997.

It refers to the various wiring rules and testing procedures that a
"prescribed item" must pass ***before*** going on sale - it has NOTHING to
do with post sale testing of condition for OHAS reasons

The same folk explained that the list of "prescribed items " which *must*
have approval is not available over the net - since it is not in the
Regulations attached to the Electrical Safety Act *but* is published in
the Government Gazette instead.

Australian Standards ( none of them law without legislation to say so ) are
not even in the right ball park.





.............. Phil

 

[Phil Allison]

"Mike Harding"
"Phil Allison"

** Shame you cannot tell shit from chocolate .

It's also a shame you no understanding of
the phrase "social skills".

** Shame you have the "social skills" of a fraud and a criminal.






........... Phil

 

[Dennis Nolan]

Phil Allison wrote:

"Dennis Nolan"

Phil Allison wrote:

My work benches have ELCBs and isolation transformers.


** Never occur to you that the using latter defeats the life saving
effect of the former ???



** Look - no answer ????




BTW Ever check the wire gauge being used in IEC leads ???

No, if it hasn't got an approval No. on it, it is chopped up and goes into
the rubbish bin.




** Those approval numbers might be faked - the Chinese do that you know.

We had a long thread about it here a while ago - the WA safety inspectors
took it real seriously.



Phil, please tell me where it is decreed that test equipment does not need
safety testing, I really want to know.



** That is not any claim that I made.

You *DO* have a serious reading comprehension problem.

Here is what I wrote again :

" Test equipment is exempt from compliance with electrical safety standards
(or EMC regs ) that apply to most appliances... "

This is exactly as said to me by the electrical safety branch of Fair
Trading, here in Sydney, when I enquired about any approvals needed for my
"RMS Current Monitor " - published in Electronics Australia magazine in Jan
1997.
Almost eight years ago.

It refers to the various wiring rules and testing procedures that a
"prescribed item" must pass ***before*** going on sale - it has NOTHING to
do with post sale testing of condition for OHAS reasons
I thought that it was impossible to change the wiring (especially the

protective earth wire) and still comply to the manufacturer's specification.

The same folk explained that the list of "prescribed items " which *must*
have approval is not available over the net - since it is not in the
Regulations attached to the Electrical Safety Act *but* is published in
the Government Gazette instead.
Try

http://www.fairtrading.nsw.gov.au/business/sellingsafeproducts/electricalproducts.html

Australian Standards ( none of them law without legislation to say so ) are
not even in the right ball park.

Again from

http://www.fairtrading.nsw.gov.au/business/sellingsafeproducts/electricalproducts_ptot.html#Power%20supply%20or%20charger
The item
Power supply for general use - AS/NZS 61558.1:2000 with amendment 1 and
AS/NZS 61558.2.6:2001.

Not hard, just a couple of minutes with Google.

You seemed to boast about selling power supplies
"I suppose it would NEVER dawn on a colossal FUCKWIT like you Nolan
how anyone can sell a bench power supply that has an output voltage of
over 100 volts DC at several amps ??" Assuming that you are responsible
for it's manufacture, you should already be conversant with AS/NZS 61558

Looks like I have to keep testing all that test equipment because
someone giving verbal advice eight years ago looks pretty feeble when
stacked up against all the Government Acts and regulations.

Have a nice day
And as Dave Allen used to say "May your god go with you"
Dennis.

 

[Caliban]

Bwahahahaha!

Nice one "Mr Pot" you're not black at all.

 

[Phil Allison]

"Dennis Nolan"
Phil Allison

Phil, please tell me where it is decreed that test equipment does not
need safety testing, I really want to know.


** That is ***NOT*** any claim that I made.

** The original debate is now OVER, since Dennis the Menace simply cannot
comprehend what he reads and has not responded to the above.




----------------------------------------------------------------------

The same folk explained that the list of "prescribed items " which
*must* have approval is not available over the net - since it is not in
the Regulations attached to the Electrical Safety Act *but* is
published in the Government Gazette instead.

Try
http://www.fairtrading.nsw.gov.au/business/sellingsafeproducts/electricalproducts.html

** Is NOT in the Act or Regs - as I said.

"I suppose it would NEVER dawn on a colossal FUCKWIT like you Nolan how
anyone can sell a bench power supply that has an output voltage of over
100 volts DC at several amps ??"

Assuming that you are responsible for it's manufacture, you should already
be conversant with AS/NZS 61558

** A 100 volt power supply for ***lab use** is not included in the
definition - you asinine fuckhead.

Looks like I have to keep testing all that test equipment because someone
giving verbal advice eight years ago looks pretty feeble when stacked up
against all the Government Acts and regulations.

** FINAL COMMENT :


There is not the *slightest* link between the rantings of this *Dennis the
Menace* mental retard and the original topic.




................. Phil