Testing metal casing for voltage

[Happyspark]

Views welcome on this subject.
I have just got involved in a upgrade project and the following part of the test procedure currently in force is as follows;
1) Isolate the supply to the unit by switching off the fused spur and removing the fuse.
2) Unscrew and remove the insulated cover thus exposing the backplate and the power supply unit.
3) Test the metalwork of the backplate and power supply unit for any stray voltages using a neon screwdriver before commencing.
It is at this point I disagree with the procedure, I do not deem a neon screwdriver to be a safe and trusted method for testing for dangerous voltages but rather the use of a recognise voltage and resistance tester such as the Fluke T100 series. The T100 Series are compliant with EN 61010-1 and EN61243-3 requirements. I am struggling to find the legal situation concerning neon screwdrivers but I have the view anyway that these should be banned.

 

[Taylortwocities]

Neon screwdrivers are unreliable and give false indications. When faulty they provide the opportunity to connect the user to a live part.



Whoever wrote that procedure should look at Guidance Note 3 (Inspection & Testing).
The standard for Test Instruments is detailed there:


4.1 Instrument standard
BS EN 61010 : Safety requirements for electrical equipment for
measurement control and laboratory use is the basic safety standard
for electrical test instruments.
The basic instrument standard is BS EN 61557: Electrical safety in low
voltage distribution systems up to 1000 V a.c. and 1500 V d.c. Equipment
for testing, measuring or monitoring of protective measures. This
standard includes performance requirements and requires compliance
with BS EN 61010.
In Section 1.1 Safety, reference was made to the use of test leads
which conform to HSE Guidance Note GS38. The safety measures and
procedures set out in HSE Guidance Note GS38 should be observed for
all instruments, leads, probes and accessories. It should be noted that
some test instrument manufacturers’ advise that their instruments be
used in conjunction with fused test leads and probes. Other manufacturers
advise the use of non-fused leads and probes when the instrument
has in-built electrical protection but it should be noted that such
electrical protection does not extend to the probes and leads.


So, does a neon screwdriver comply with the above?

Should the use of one be provided in test procedures?

 

[bernardgreen]

3) Test the metalwork of the backplate and power supply unit for any stray voltages using a neon screwdriver before commencing.

The metal work could be perfectly well earthed but the neon glows, the stray voltage being from you being isolated from earth and close to live conductors which have capacitively induced a voltage on you.


On one place for neon screw drivers........ In the BIN

 

[Goldberg]

I have just got involved in a upgrade project...

Please could you explain what this means?

For example, is this a private project involving only you and your house?

Or is it in the course of your job? If so, what is your role, and are you trained and insured to fulfill your duties?

Is the project supposed to conform with any particular safety standard?

3) Test the metalwork of the backplate and power supply unit for any stray voltages

What does this mean to you?

What is a "stray" voltage?

...concerning neon screwdrivers but I have the view anyway that these should be banned.

Why banned? They're extremely useful, although volt sticks are better. As with anything you need to understand their limitations. And if you don't understand, you shouldn't be working with electricity.

 

[Taylortwocities]

On one place for neon screw drivers........ In the BIN

Untitled

• Taylortwocities
• 11 Feb 2009
• 20

 

[Happyspark]

I have just got involved in a upgrade project...

Please could you explain what this means?
It means I will be doing the work.
For example, is this a private project involving only you and your house?
This is a business contract in the course of my job
Or is it in the course of your job? If so, what is your role, and are you trained and insured to fulfill your duties?
I am trained and insured.
Is the project supposed to conform with any particular safety standard?
as such it will conform to the IEE 17th Edition Regs

3) Test the metalwork of the backplate and power supply unit for any stray voltages

What does this mean to you?
In the past there has been instances of the backplate becoming live.
What is a "stray" voltage?
An electrical fault causing the backplate to become live due to no earthing arrangement The procedure was not written for trained electricians but for people working on the units with little electrical knowledge

...concerning neon screwdrivers but I have the view anyway that these should be banned.

Why banned? They're extremely useful, although volt sticks are better. As with anything you need to understand their limitations. And if you don't understand, you shouldn't be working with electricity.

It is not a case of working with electricity but a case of making sure that the case as not become live and there being a possibility of shock to the person working on the unit.

 

[kirkgas]

I have just got involved in a upgrade project...

Please could you explain what this means?
It means I will be doing the work.
For example, is this a private project involving only you and your house?
This is a business contract in the course of my job
Or is it in the course of your job? If so, what is your role, and are you trained and insured to fulfill your duties?
I am trained and insured.
Is the project supposed to conform with any particular safety standard?
as such it will conform to the IEE 17th Edition Regs

3) Test the metalwork of the backplate and power supply unit for any stray voltages

What does this mean to you?
In the past there has been instances of the backplate becoming live.
What is a "stray" voltage?
An electrical fault causing the backplate to become live due to no earthing arrangement The procedure was not written for trained electricians but for people working on the units with little electrical knowledge

...concerning neon screwdrivers but I have the view anyway that these should be banned.

Why banned? They're extremely useful, although volt sticks are better. As with anything you need to understand their limitations. And if you don't understand, you shouldn't be working with electricity.

It is not a case of working with electricity but a case of making sure that the case as not become live and there being a possibility of shock to the person working on the unit.

Happyspark, BAS is going to give you pelters for this shambes of a reply as he will need to take about 4-5 seconds to realise you are too lazy to compose a proper reply

 

[Happyspark]

Sorry for messing up it's my first day using the site.

 

[ericmark]

Views welcome on this subject.
I have just got involved in a upgrade project and the following part of the test procedure currently in force is as follows;
1) Isolate the supply to the unit by switching off the fused spur and removing the fuse.

There should be a lock or other item requiring a tool to remove even a cable tie would do through the hole in fuse carrier so the fuse can’t be replaced without the person realising it was isolated intentionally.

2) Unscrew and remove the insulated cover thus exposing the backplate and the power supply unit.
3) Test the metalwork of the backplate and power supply unit for any stray voltages using a neon screwdriver before commencing.

It is at this point I disagree with the procedure, I do not deem a neon screwdriver to be a safe and trusted method for testing for dangerous voltages but rather the use of a recognise voltage and resistance tester such as the Fluke T100 series. The T100 Series are compliant with EN 61010-1 and EN61243-3 requirements. I am struggling to find the legal situation concerning neon screwdrivers but I have the view anyway that these should be banned.

Although I would agree one should not rely on neon screwdrivers never the less using one as a secondary indication when someone have broken the rules and re-connected a supply while your working on it, or when there are borrowed neutrals and on disconnection a wire becomes live is a good precaution and I feel they do have their place. But there place is not to prove dead. Neither is any test device which can be set to wrong range so not a standard multi-meter.

However to test for dead you must have two test points and you only refer to “Back Plate” without knowing more we can’t really comment on how one could test.

I would guess that some earthing procedure may be called for! I do remember working on HF welding units and we had a wand filled with resistors that we had to touch to the main valve connections before doing any work on the unit. (They worked at 27MHz at 7Kw I wondered if I could adapt for CB radio?)

But to test, leak to earth, or short to earth, you must have an earth connection and only you can tell us if this exists.

 

[Happyspark]

OK, lets get down to the question being asked and not the issue of whether a neon screwdriver should be banned or as its place, the question was
[/quote: I am struggling to find the legal situation concerning neon screwdrivers]
If a neon was used and then caused injury through being faulty how would that hold up in a court of law?
You say it can be used as a secondary device but again the question is, is it wrong to use it as a primary device. Finally there are a number of points in close proximity that are earthed.

 

[Happyspark]

Still haven't got the hang of quoting

 

[holmslaw]

..

 

[Happyspark]

What I am trying to do is change the procedure currently in place (not written by me) to a more suitable and practical one. However I have to prove to the author and company that the neon screwdriver test is not a reasonable practical measure, or better still, illegal when used in this circumstance. The BS7671 and Guidance Note 3 are references for qualified electricians but not statuary documents but would however go a long way in court to prove that an Employer has taken all reasonable practical measures to ensure that a safe method has been used.
The persons using the neon screwdrivers are not qualified electricians but rather trained technicians working on their equipment with minimal amount of electrical knowledge. They are only proving that any metalwork associated with the equipment is not live. In the past it has been known for the metalwork to become live because of the wall fixings penetrating the live conductor and the metalwork not having earth continuity.
The answers I am looking for is in relationship to the neon screwdriver rather than another preferred method. Saying that any answers relating to the subject are useful to know and I thank everyone so far for their responses.

 

[holmslaw]

..

 

[Spark123]

Furthering what holmslaw said re the EAWR the HSE issue guidance on the test equipment (GS38) now available as a free download here: http://www.hse.gov.uk/pubns/priced/gs38.pdf