RRANES
New member
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- Lakewood, Colorado
What is the relationship between NEC and UL. I know that UL is a testing agency.
UL vs NEC
- Thread starter RRANES
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bphgravity
Senior Member
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- Florida
In some cases, the NEC calls for materials and equipment to be listed. In all cases, listed and labeled equipment must be installed and used in accordance with the listing and labeling instructions. UL is one agency that provides the guidelines for these products.
The basica idea is that a third part organization has looked at materials and equipment and has found them suitable for a specific use. UL is only one of several Nationally Recognized Testing Laboratories.
The basica idea is that a third part organization has looked at materials and equipment and has found them suitable for a specific use. UL is only one of several Nationally Recognized Testing Laboratories.
renosteinke
Senior Member
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- NE Arkansas
UL vs NEC
There are two distnct answers to this question...and both are correct.
UL tests to "standards." These standards are developed (supposedly) with input from manufacturers, consumers, engineers, and code officials. As you might guess, there is a strong desire that different standards be consistant with each other- so every UL standard refers to numerous other organisations' standards. The NEC is one of the primary codes referenced by UL in it's standards.
The NEC, on the other hand, is developed by "consensus," in an "open process" where anyone may make a proposal. Proposals are reviewed by volunteer panels...then voted upon at conventions where the idle rich go when they have nothing else to do. It should come as no surprise that many code panels have members who are there representing UL.
One issue, in particular, serves to illustrate the relationships between these varied groups.
The NEC simply says equipment must be suitable for its' environment. So- what is the environment?
For decades, UL tested, using it's own tests and NEC terminology, for "wet," damp," and "dry" locations.
During this same period, NEMA -a trade group of manufacturers- developed an extensive list of different types of enclosures. UL did a very good job of never admitting the existance of NEMA, and completely ignored NEMA enclosure types, and the NEMA tests.
The best comparison could be made between a "NEMA-3R" enclosure, and a UL "Wet location" listing. The tests were similar, but not identical. Both standards also contained differing requirements that had nothing to do with rain entry. You could not honestly say they were the "same," even though I can't imagine something passing one and not the other!
This all ended when the NEMA standard was recognised by ANSI (a semi-governmental standards group). With this recognition, UL suddenly "saw the light," and admitted that NEMA classifications had some validity.
UL, and the NFPA, can best be imagined as two octupi hugging. Each is separate, distinct...and hopelessly entwinned in the other!
There are two distnct answers to this question...and both are correct.
UL tests to "standards." These standards are developed (supposedly) with input from manufacturers, consumers, engineers, and code officials. As you might guess, there is a strong desire that different standards be consistant with each other- so every UL standard refers to numerous other organisations' standards. The NEC is one of the primary codes referenced by UL in it's standards.
The NEC, on the other hand, is developed by "consensus," in an "open process" where anyone may make a proposal. Proposals are reviewed by volunteer panels...then voted upon at conventions where the idle rich go when they have nothing else to do. It should come as no surprise that many code panels have members who are there representing UL.
One issue, in particular, serves to illustrate the relationships between these varied groups.
The NEC simply says equipment must be suitable for its' environment. So- what is the environment?
For decades, UL tested, using it's own tests and NEC terminology, for "wet," damp," and "dry" locations.
During this same period, NEMA -a trade group of manufacturers- developed an extensive list of different types of enclosures. UL did a very good job of never admitting the existance of NEMA, and completely ignored NEMA enclosure types, and the NEMA tests.
The best comparison could be made between a "NEMA-3R" enclosure, and a UL "Wet location" listing. The tests were similar, but not identical. Both standards also contained differing requirements that had nothing to do with rain entry. You could not honestly say they were the "same," even though I can't imagine something passing one and not the other!
This all ended when the NEMA standard was recognised by ANSI (a semi-governmental standards group). With this recognition, UL suddenly "saw the light," and admitted that NEMA classifications had some validity.
UL, and the NFPA, can best be imagined as two octupi hugging. Each is separate, distinct...and hopelessly entwinned in the other!
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