What is UL. 2

[mechantaeus]

Hello Group:
This one's easy.
In Electrical lingo what is UL?
Thanks,

-mechantaeus

----------------------------------------
Work Hard and Work Smart.

 

[MadMango]

The only thing I can think of is Underwriters Laboratories Inc., a compliance firm/body.

http://www.ul.com/

[green]"I think there is a world market for maybe five computers."[/green]
Thomas Watson, chairman of IBM, 1943.
Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[jraef]

Underwiters Laboratory is a testing firm in the US which tests products for safety, primarilly fire safety. For electrical products, this means that if UL listed, they have been tested at the lab for whatever protective functions they provide and/or electrical fire safety standards they need to meet. it has nothing to do with quality, reliability or functionality, only fire safety. Many inspection authorities in the US however rely upon UL listing as a de-fact standard of quality, assuming that if they will not catch on fire they must have been built correctly.

The biggest issue in the US however is that ionsurance companies often require UL listing of equipment, and if a fire is caused by a non-listed device, they may not cover the cost of the fire damage.

"Venditori de oleum-vipera non vigere excordis populi"

 

[IRstuff]

As the name might imply, UL was originally started as an offshoot of the National Board of Fire Underwriters:

http://www.ul.com/about/history/1890/

TTFN

 

[ecreek]

Underwriters Labratory. They test products to insure that they are safe to use. Costs money.

 

[don01]

ecreek & co are right it is underwriters laboratory

but be aware that they are a quality systems auditor and accrediting agency. They will support clients for ISO QS AS and nearly all the international standards and as such thier mark is copyright and is used on many a business card to show "who" is the testing agency just as say LLoyds register or Standards Australia might. I have worked with them on ISO900x work systems for the chemical industry and QS200x work and documentation for the auto industry

Really what I'm saying is the UL mark is not limited to an individual standard

Regards
Don

 

[mechantaeus]

Thank you all

-antaeus

Work Hard and Work Smart

 

[buzzp]

I must disagree with jraef. UL does not test for operating characteristics. You could send them a voltage relay and they could care less if it trips when it says or times out when it says. If it does not cause a fire hazard, it will be UL listed or recognized. This is true for UL's industrial control equipment category, UL508. If you want assurance that the product will not cause a fire, look for a UL mark. If you want it tested for functionality, then look to some of the European marks (safety and quality).
UL may provide some specialized services for testing a products operation but, in general, you can safely assume that the UL mark has nothing to do with quality only safety.
Also, UL listed or recognized products are not guaranteed to prevent a lawsuit in the event of a fire. It will reduce the chances of a successful lawsuit by prooving intent. If anything has changed with a product and it was not approved by UL and you still carry the mark, you could be opening yourself up.

 

[IRstuff]

About UL
Underwriters Laboratories Inc. (UL) is an independent, not-for-profit product-safety testing and certification organization. We have tested products for public safety for more than a century.

Since our founding in 1894, we have held the undisputed reputation as a leader in product-safety testing and certification within the United States. Building on our household name in the United States, UL is becoming one of the most recognized, reputable conformity assessment providers in the world. Today, our services extend to helping companies achieve global acceptance, whether for an electrical device, a programmable system, or an organization's quality process.

TTFN

 

[jraef]

In response to don01, we do in fact use UL for additional QC testing to other standards, but as buzzp commented, this is essentially an adjunct function of their primary mission. Just because something has a UL label on it does NOT mean that it was functionally tested beyond the basic fire prevention standards. If the UL lable also includes additional information as to ISO, CE or other test standards then it is a safe bet that the tests were performed fairly and professionally for sure. However one cannot assume any more than what they print on the label, and if it is just the UL mark, then it is the bare minimum.

"Venditori de oleum-vipera non vigere excordis populi"

 

[mechantaeus]

THANK YOU ALL

Work Hard and Work Smart

 

[busbar]

 
UL is one of many NRTLs {nationally-recognized testing laboratories} on the North American continent.

http://www.osha.gov/dts/otpca/nrtl/

UL also publishes handsomely priced product standards that are typically used by other NRTLs and referenced in design specifications.