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How can UL listing be better than ETL listing?

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SuppressionAmber12

Electrical
Nov 13, 2013
4
A recent test we had completed shows a 150 TPMOV blowing up after two separate tests. This TPMOV is UL listed. This 150 TPMOV was tested at 480 volts ac at 5kA and at 480 volts ac 10 kA. Both times it was demolished. UL refused to comment, as this was not supposed to happen.
 
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First of all, UL tested the device to a standard that is designed to prevent fires and injuries. They don't really care if it fulfills its advertised purpose or not. You should get a copy of the UL standard and have a read through it.

UL listing can be construed to be better because:

1) Lots of specifying engineers have UL in their specs, but no substitutes like ETL, CSA, TUV, MET, etc...
2) When building a product to be UL listed, only UL listed parts will be approved.

Testing-wise, UL is equal to ETL, TUV, CSA, MET, and the others. Except UL is way more expensive.

Best to you,

Goober Dave

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It amazes me that a product UL Listed will blow up when tested, this is not very safe. It obviously could not pass the test to prevent injuries because had that particular unit blown up that violently with a customer around there would have been major injuries. Also Schneider products APC SurgeArrest (UL listed ) are being recalled for melting, smoke damage, and fire! I am beginning to think ELT is better, because they test safety and performance, and because they are internationally recognized. Besides all are equal on NRTL.
 
2) When building a product to be UL listed, only UL listed parts will be approved.

I have heard of UL fining people for using devices other than UL listed in this case being fined, but I have also heard that is illegal for UL to fine them. Any information about this?
 
Yes, it's not illegal for UL to reject or charge more for a non-UL component. It's not actually a fine -- if the part us UL listed, you don't have to pay to test that part and you must pay for it. But if it's ETL or other listing, UL must test the part. In UL508a control panels, a non-UL part can be used but it's like going through a world war and King Faisals's budget to get it accomplished.

On the issue of exploding MOVs -- the samples that UL tested did not explode under the test procedures in the standard. There is not a guarantee that the MOVs will work properly under the manufacturer's specifications.

In other words, the test labs (all of them) only run the tests specified in the standard. There's no guarantee that the product will meet the manufacturer's spec.

Best to you,

Goober Dave

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I forgot to ask -- is there a UL file number for your exploding MOVs? I'd like to look at the procedure if I have access to it.

Best to you,

Goober Dave

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Unfortunately our company paid to have another company test the device as we didn't believe it to be reliable, so the video we have is not available for public, however we presented it to UL as 2 separate TPMOV blew up. They did not want to discuss it with us though.
 
Yah, UL doesn't really have any responsibility other than the actual samples they tested. What a racket!

Best to you,

Goober Dave

Haven't see the forum policies? Do so now: Forum Policies
 
Based on my experience
UL is far more stringent that ETL...
and
If your product will ever be a component in another product/system that requires listing/certification then use UL or make darn sure that your product will NEVER go into a system that uses UL for approval..

and its OSHA that should get a slap on the wrist for not enforcing that all NTRL's are equal as far as accepting other NRTL's certifications/documents,etc...
All other NRTL's besides UL have no problem accepting each others data.. UL will just throw everyone elses in the trash as meaningless to them..
 
One issue is that ETL and other NRTLs do not create and publish their own standards, they test to UL's standards! So of COURSE the other NRTLs are not going to have a problem accepting UL listed components, they ALREADY are using UL's products!

Also, the test criteria for SPDs (the new terminology) under UL1449 has changed a lot in the past few years. To be fair, you must know the "Edition" of the test standard. The latest, the 3rd Edition that came out in 2009, and substantially increased the testing requirements. So if you tested a device that was listed under Edition 2, against the Edition 3 tests, yes, it would likely fail.

"Will work for (the memory of) salami"
 
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