Author Topic: Impressive Meter Blow-Out  (Read 13975 times)

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Offline Neilm

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Re: Impressive Meter Blow-Out
« Reply #25 on: January 22, 2011, 10:49:30 am »
For everyone thinking Gossen set this up by deliberately using a very high voltage, note that IEC61010 requires equipment to safely handle transient voltages of up to 8kV with an extremely low output impedance, depending on CAT rating and voltage. And these tests are based on the kind of available energy in real high-power circuits. And yes, this includes the amps jack (ever wonder why Fluke/Agilent use those expensive fuses?). The original Fluke 77 was not IEC(6)1010 rated, so it didn't have to conform to those specs. Multimeter safety has actually improved since then, it's not just marketing and a flashier case.

Actually, if your meter is rated to 1000V CATIV I believe 61010-1 calls for a 12kV pulse.

Neil
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alm

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Re: Impressive Meter Blow-Out
« Reply #26 on: January 22, 2011, 11:06:07 am »
Actually, if your meter is rated to 1000V CATIV I believe 61010-1 calls for a 12kV pulse.
You may be right. Last time I checked, no common DMM went beyond CAT IV 600V, but that was a number of years ago.
 

Offline saturation

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Re: Impressive Meter Blow-Out
« Reply #27 on: January 22, 2011, 02:06:21 pm »
A bottom line in DMM safety it should meet the safety ratings of its highest voltage range.  If a cheapo has 1000Vdc or AC range, it must be able to pass the CAT rating for that range.

It doesn't even discuss the ratings of the probes, which is not tested.  Even if you have CAT rated probes but they have been abused or worn, they can still fail.

AFAIK, no agency in the US enforces CAT ratings except OSHA.  The main target of untested meters is consumers, at least in the US, and the only way to seek redress for injury is a personal injury suit.  Likewise, in work related injuries, an employer who doesn't specify and make reasonable enforcement of DMM safety, is liable to both OSHA [ criminal neglect] and a personal suit by the employee [civil complaint].

So far the injuries are rare, but its so easily avoided why gamble with your body parts or life?  Safety should be taught as a way of life, not as an afterthought.

FWIW, a single trip to the ER in the USA, without treatment is $500 [just to evaluate and see what you need].  Reasons for well being aside, its not cost effective if you misuse a meter without safety features.
Best Wishes,

 Saturation
 

Offline EEVblog

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Re: Impressive Meter Blow-Out
« Reply #28 on: January 22, 2011, 10:01:32 pm »
Amazing as it may be, there are still skeptics of multimeter safety. My theory is that some people just can't imagine electricity doing anything other than shocking you. Maybe you have to see an electrical explosion in real life to believe that it can happen.

I think most believe it can happen, they just believe it can't happen to them because they aren't working in a substation or something.
The thing they fail to understand is once you touch any aspect of the mains, you have a potential (no pun intended) high energy source that can surge at any given time.

Dave.
 

Offline Kiriakos-GR

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Re: Impressive Meter Blow-Out
« Reply #29 on: January 23, 2011, 01:36:28 am »
Last night I had see on TV , one story about the large American airplanes , with aged electrical wiring,
that they have problems after 15 - 20 years of use , and the companies they do not replace then !! because it cost allot , and if 4-5 airplanes fall and crash because of it every year  ...  it called as " cost of doing business ".

Luckily about the electrical measurements , the risk goes 100% at the one who does the job.
And about how strictly he will follow the rules , its his own personal choice.  

By the same way of thinking , if some one are so strict about security and health maters,
he must never get aboard on an airplane, ever !!
 

 
« Last Edit: January 23, 2011, 01:39:17 am by Kiriakos-GR »
 

alm

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Re: Impressive Meter Blow-Out
« Reply #30 on: January 23, 2011, 05:56:35 am »
By the same way of thinking , if some one are so strict about security and health maters,
he must never get aboard on an airplane, ever !!
Still safer than cars by a long shot, not sure how occupational hazards compare. It's also about costs/benefit. The price of a good DMM is a few hundred dollars, which you can use for many years. The costs (in time) of taking the boat/train instead of flying, or changing jobs/vacation destination, is likely to be much higher.
 

Offline Kiriakos-GR

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Re: Impressive Meter Blow-Out
« Reply #31 on: January 23, 2011, 06:43:53 am »
Your diplomacy  does now work here  :P

And I was aware that there was no hope to agree with me,
and so I am not surprised ..  :)
 

Offline Neilm

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Re: Impressive Meter Blow-Out
« Reply #32 on: January 23, 2011, 10:27:46 am »

It doesn't even discuss the ratings of the probes, which is not tested.  Even if you have CAT rated probes but they have been abused or worn, they can still fail.


Probes, leads and accessories for test and measurement equipment are also covered by IEC61010. Probes and probe assemblies are covered by IEC61010-031. If a manufacturer claims it complies to IEC61010 then the probes supplied with the instrument must have been tested and rated correctly.

IEC61010 edition 3 was released last year and currently manufacturers are revisiting instruments and probes to test if they comply to the new standard - so expect that DMMs and spares will all change over the next 18 months or so.

Yours

Neil
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Offline Kiriakos-GR

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Re: Impressive Meter Blow-Out
« Reply #33 on: January 23, 2011, 05:07:23 pm »
Quote
IEC61010 edition 3

IEC 61010-1 ed3.0

http://webstore.iec.ch/webstore/webstore.nsf/standards+ed/IEC%2061010-1%20Ed.%203.0?OpenDocument

There it is 322 pages PDF !!

But even so, practically the what ever changes will touch the market after 3-4 years. (practically) .

We have many examples of some rules , that  (practically) was not usable.

End so it will not be an mystery to me, if there will be any IEC 61010-1 ed3.0a ,
that sorts out such cases.

Oh my , it looks that even the document has an price of 300 CHF (Swiss francs),
or 312$  ..    




« Last Edit: January 23, 2011, 05:14:25 pm by Kiriakos-GR »
 

Online Simon

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Re: Impressive Meter Blow-Out
« Reply #34 on: January 23, 2011, 08:57:21 pm »
I think people forget that the mains can unleaser some high power and when you pump power/heat into a confined space things start to expand fast. after all gunpowder on its own just burns violently, encase it and then set light to it and the sudden presure in the confined space produce an explosion, same with pumping power into small items
 

Offline Neilm

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Re: Impressive Meter Blow-Out
« Reply #35 on: January 23, 2011, 10:07:04 pm »
Quote
IEC61010 edition 3

IEC 61010-1 ed3.0

http://webstore.iec.ch/webstore/webstore.nsf/standards+ed/IEC%2061010-1%20Ed.%203.0?OpenDocument

There it is 322 pages PDF !!

But even so, practically the what ever changes will touch the market after 3-4 years. (practically) .

We have many examples of some rules , that  (practically) was not usable.

End so it will not be an mystery to me, if there will be any IEC 61010-1 ed3.0a ,
that sorts out such cases.

Oh my , it looks that even the document has an price of 300 CHF (Swiss francs),
or 312$  ..    



There is always a transition period when a new standard comes out, usually three years. In Europe, the date of adoption is is when the standard is published in the Official Journal. The new standard includes things that were not considered on the previous standard, the main one being rules for insulation on multi-layer PCBs.

Each time we produce a new instrument at work, someone has to sit down and go through that document clause by clause and produce a report to say that the product meets each point, test or requirement.

As for the edition 3.0a - I jolly well hope so as there is a monumental inconsistancy in two to the tables relating to mains clearance. It appeas that someone has transposed a couple of digits and it made its way through all the committee stages, ( there were at least 2 CDVs that I know of) without being spotted. We spotted it at work when working out a spreadsheet to calcultate creepage, clearance and test voltages.

Neil
Edit
CDV is a code used for standards work. It stands for Committee Draft for Voting. Basically, when it reaches this stage a draft standard is sent around all the members and they can either accept the draft or reject it.  The votes are tallied and if the magic number is reached the standard is accepted, if not it all starts again
« Last Edit: January 23, 2011, 10:10:39 pm by Neilm »
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