What is the name of the governing body on industrial standardisation (standardization) in USA?

NIST does indeed publish such standards. FIPS-140 (Federal Information Processing Standards number 140) was the standard we used to design commercial crypto gear. The Fed likes their own standards. ;-)

That's your Homeland Security dept - launched after 9/11, surely? Jim

"John Larkin" wrote in message news: snipped-for-privacy@4ax.com...

NIST sounds like it's the all-embracing Federal or Central body of standardising different knots of know-how. This'll do me for now! Jim

I read in sci.electronics.design that martin griffith wrote (in ) about 'What is the name of the governing body on industrial standardisation (standardization) in USA?', on Tue, 29 Mar 2005:

Well, they should not have. They are not supposed to assume that anything that is documented will not be AS documented. (But the extent to which they can pile up worst-worst-worst... combinations of

I read in sci.electronics.design that John Larkin wrote (in ) about 'What is the name of the governing body on industrial standardisation (standardization) in USA?', on Tue, 29 Mar 2005:

Thank you. I will worship there daily. (;-)

I read in sci.electronics.design that Tim Shoppa wrote (in ) about 'What is the name of the governing body on industrial standardisation (standardization) in USA?', on Tue, 29 Mar 2005:

I thought NIST was more like our (UK) National Physical Laboratory, which is a national 'standards' body with a different meaning of 'standard'... the UK standard metre, volt, amp, ohm etc. live there.

The NPL campus is very interesting. It contains an apparently infinite number of standard acres, and the time taken to find your way around it without a map is one standard fortnight.

In Britain it is the BSI. In Germany it is DIN. The ISO is multi-national. The European Union now has the CEN.

What is the closest central technical authority in the USA?

There's not a single agency. There are many government and civillian agencies that provide "guidelines" which may be incorporated into legal codes (such as electrical or building codes). Some of thse are:

NFPA - Nat'nl Fire Prevention Assn. ASTM - American Socity for Testing and Materials ANSI - American Nat'nl Standards Inst. ASM - American Society of Metals SAE - Society of Automotive Engineers ASME - American Society of Manufacturing Engineers

Plus the myriad alphabet soup of govt. agencies.

UL doesn't do house wiring. That's NEC (National Electrical Code) country. UL does product-safety testing and certification. See [

UK is single phase 230V and neutral, right? Split phase 115-neutral-115 (230 total) wiring would have about the same shock potential as the US system.

I read in sci.electronics.design that Jim Gregory wrote (in ) about 'What is the name of the governing body on industrial standardisation (standardization) in USA?', on Tue, 29 Mar 2005:

Well, we do, but it doesn't do electrical products (yet!). It's the Loss Prevention Council, and it was, like UL, set up by the insurance industry. Safety of 'consumer electronics' was, however, handled by British Standards (in BS 415) from 1931; the first edition covered only mains-supplied 'battery eliminators'.

On this side of the pond, most houses are not wood-framed (except in old Norwegian villages, where the 'frames' tended to be 30 to 60 cm square baulks which would not burn easily!), so our electrical safety standards have tended to concentrate on electric shock rather more than on fire prevention. In a land of 120 V mains and timber-framed houses, it's not surprising that UL has opposite priorities.

TUV said that they wanted X mm clearance on some tracks, no prob,but it was a very tight layout. I had a really enjoyable time doing it. Then they said what if they make the boards wrong, ie too small, by

But I said if the board was 10% smaller it wouldnt fit on the mounting holes and most of the components wouldnt fit, and we would reject them. Nope they said....

The client must have got the "straight out of college" engineer

martin

Opinions are like assholes -- everyone has one

Balanced 240 would certainly work. In the US, big appliances like air conditioners and clothes driers in fact use 240 volts with a 3-prong plug: 120/120/ground. That's actually the ideal circuit: it has the low shock properties of US 120, but the low fire hazard of European

Of course. Nothing but self-inflicted arson would void an insurance policy.

John

I read in sci.electronics.design that martin griffith wrote (in ) about 'What is the name of the governing body on industrial standardisation (standardization) in USA?', on Tue, 29 Mar 2005:

It's the sort of trap you can fall into when your priority is doing the job rather than providing formal documentation.

In the days before CAD, PC artworks were made with black tape, N-times full size, with fiduciary marks labelled 'Reduce to X.00 mm +/- 0.1 mm' or something like that. Our quality people DID sample check a few key dimensions on the printed boards as well as the fiduciary, to make sure the boards weren't tilted in the camera or the lens system was out of spec. We did occasionally get 'tilted' boards.

If your procedures using CAD can't provide equivalent checks, then TUV have a case. A critical clearance MIGHT be 10% down (if, for example 10% is 0.4 mm), because your procedures don't have any way to detect that. OTOH, if your procedures DO cover that, TUV don't have a case.

I read in sci.electronics.design that Jim Thompson wrote (in ) about 'What is the name of the governing body on industrial standardisation (standardization) in USA?', on Tue, 29 Mar 2005:

Note the hyperbolic verb, and the smiley.

Something i never considered is:

I normally sent gerbers to the client, who passed them onto China with a screendump/print of the PCB, showing possible DRC's, my comments, etc. The gerbers effectively ARE the documentation, arnt they?

How do you put tolerances in a gerber file? I'm not really au fait with gerber format, I just press the button to generate the files and check that they read out in a third party viewer, say GC Preview.

I just assumed that there are no tolerances in a gerber file.

Sorry if this seems a little dumb

martin

Opinions are like assholes -- everyone has one

I read in sci.electronics.design that Guy Macon wrote (in ) about 'What is the name of the governing body on industrial standardisation (standardization) in USA?', on Tue, 29 Mar 2005:

I know that. UL is concerned with appliances burning up. Look at all the stuff in IEC 60950 about 'fire enclosures'. That's almost all derived form UL.

But you are less likely to touch both 'lives' than one 'live' and neutral or ground.

Any country that uses 110V -120V in domestic (and commercial premises) wiring must use twice as much copper and brass by weight in infrastructure as needed for a 220V - 240V supply, based on same MegaWatts of lighting and power used (wasteful is that trend). National EHV grid potentials are the same most of the world, but after comparative distribution, the halved step-down voltage seems uneconomical in practice. Incidentally, to come into line with other places, we have dropped our AC line specification from 240V to 230V in the last twelve years. ELCBs or RCDs can trip very quickly indeed if exposed live mains is touched accidentally. For the very reason you suggested, some temporary-site safety step-down transformers give 115V centre-tapped, but it is not *standard* here yet, but no safety earth (a separate neutral) is possible with a balanced system, unless 4-pole connectors are adopted.

Question If a house fire were blamed on the failure of a piece of AC equipment that turned out forensically not to have UL (or LPC) certification, and the occupier had paid his insurance premium, would resulting fire damage claims for contents and property still be paid out nevertheless?

...........

Standards are great things. That's why we have so many of them to choose from.