UL / NRTL

[CEDEng]

Thanks ahead of time!

This is roughly a safety question, so I put it here - it's not really NEC, and there is no NRTL topic yet, sooooooo here we are!

I need help! And direction! My eyes are sore with googling this topic, information is confusing and conflicting, and often missing.

I build machines, custom stuff. They are "industrial control panels" at their heart, so I follow those standards. Those standards do not mention hazards outside the box - guarding, moving parts, etc.

If I get something built by a UL panel shop - it does not necessarily mean the OUTSIDE is Osha safe...right? If I want something NRTL (UL...etc...) "certified," will it THEN get a Badge of Safeness?

Since I can become a UL panel shop (with effort and cash) - regarding the INSIDE of the panel - can I also become a UL (or substitute org.) "safety" shop?

My machines are one of a kind. It seems impractical to spend $10 to $20 grand apiece to have them inspected and tested by any NRTL, when many times the machine itself is only worth half that.

Other folks must be in this same boat...how does it work you?

 

[petersonra]

There are several companies (I think including UL) that will "certify" the safety of your machine for a fee.

It is a much harder and more expensive thing than listing of UL508a panels.

I agree it is not worth doing unless you can spread the cost out over many units.

 

[CEDEng]

Well...I think we all agree it's not worth the $$...in some sense.

Unfortunately, it's no longer optional. Our customers are insisting on the NRTL tag (be it UL or whoever), specifically with regard to safety. That's why I'm wondering how other "custom" shops are getting by...

Thanks for the input!

 

[petersonra]

Well...I think we all agree it's not worth the $$...in some sense.

Unfortunately, it's no longer optional. Our customers are insisting on the NRTL tag (be it UL or whoever), specifically with regard to safety. That's why I'm wondering how other "custom" shops are getting by...

Thanks for the input!

I have not run across anyone requiring a NRTL listing on a custom machine for safety or anything else. However, it is very common to require listing of just the control panel.

 

[CEDEng]

Yeah, until now we haven't either.

But - somewhat suddenly - there is a gigantic push towards being "NRTL Certified," which I think is partially a result of the customer not fully understanding what they're asking for in terms of practicality or money. They just heard "it was a good idea," and there ya go.

Good news, I suppose, is that no one will be able to do it for less money, so it might as well be us - we just wrap it in the price, however unpleasant.

Even UL panel shops (part of my original question) might make the PANELS to UL wiring standards...but is the ENTIRE MACHINE UL Safety "certified" - do UL panel shops ALSO follow the other standards (not just wiring) that cover all the bases? That seems unlikely...but then again, that's why I'm asking!

 

[ron]

What would the NRTL test be based on? Heating and Cooling Equipment, UL 1995?

 

[petersonra]

A UL panel shop can only deal with the control panel.

The machine safety aspects have almost nothing to do with the control panel. The machine as a whole can be safe, unsafe, or some place in between with a perfectly fine UL listed control panel.

They just are not directly related.

 

[CEDEng]

Thanks again for the input.

I don't want to get to pigeon holed into UL - I am just using them as a well-known NRTL.

While the UL "panel standards" (UL508A, or such...i'm no expert, obviously) have nothing to do with machine safety, there are absolutely machine safety standards (like UL1998, or more generally, IEC61508) that UL can use to evaluate a machine based on "safety" and not, essentially, good wiring practice.

Or if not UL - then someone - some other NRTL - is using a "standard" to "certify" that you've built it to some ...well, standard.

For instance, we CE mark - that is, we pay a fortune to have someone evaluate our machines, and make sure they adhere to the machine directive and other standards regarding safety (and the rest).

So my question is - if a UL panel shop is "certified" or whatever you want to call it - to be following UL "wiring standards" (via audits and so forth), are there places that ALSO follow UL (or other) "safety standards" for machine safety, and if so, can I learn to do it, and if not, who are these shops?

 

[petersonra]

Thanks again for the input.

I don't want to get to pigeon holed into UL - I am just using them as a well-known NRTL.

While the UL "panel standards" (UL508A, or such...i'm no expert, obviously) have nothing to do with machine safety, there are absolutely machine safety standards (like UL1998, or more generally, IEC61508) that UL can use to evaluate a machine based on "safety" and not, essentially, good wiring practice.

Or if not UL - then someone - some other NRTL - is using a "standard" to "certify" that you've built it to some ...well, standard.

For instance, we CE mark - that is, we pay a fortune to have someone evaluate our machines, and make sure they adhere to the machine directive and other standards regarding safety (and the rest).

So my question is - if a UL panel shop is "certified" or whatever you want to call it - to be following UL "wiring standards" (via audits and so forth), are there places that ALSO follow UL (or other) "safety standards" for machine safety, and if so, can I learn to do it, and if not, who are these shops?

To the best of my knowledge UL and other entitites that are certifying or listing anything to do with safety are doing it themselves and not certifying 3rd parties to do it (a la UL508a shops).

Incidentally, for the most part you can self certify for CE. There is no general requirement that a 3rd party be involved at all, except for certain special cases such as equipment for use in classified areas.

The thing about machine safety is that the electrical, controls, and wiring part of it is actually a relatively small piece of the puzzle.

 

[Jraef]

First off, understand that EVERYTHING that UL deals with can be defined as a "safety standard", so your way of describing having UL508A listing as something other than a safety standard is possibly selling yourself short to a customer who cannot be any more specific than to say "I want a safety certificate". That IS what a UL508A label is.

But of course you are being more specific about things like guarding, safety interlocking etc., I get it. UL and other NRTLS (who for the most part use UL's standards anyway) have some narrowly specific testing and listing standards for certain types of machines, but unless your machine fits in one of those pigeon holes, there is no "general" safety standard that they can apply. Part of that problem is that here in this country we have yet to legislate the requirement for such a thing, it is basically undefined in an enforceable way. OSHA is as close to we get, but OSHA operates in an "after the fact" manner; after they investigate an accident, they swoop in and find out what you didn't do. But if you want to be proactive with them, they point you to vague standards saying that it's your responsibility.

Internationally however, there are more clear and specific standards that can be followed and enforced. UL and other NRTLs can certify to these other standards, but if your users cannot identify to you which ones they need certification to, you can end up spinning your wheels and wasting money.

But that said, I have found that an NRTL named TUV has become very adept at doing safety evaluations, and then advising on deciding on applicable certifications you can go for. They don't have as many offices around the country as UL, but they travel. I highly recommend that you find and talk to their most local office about this. It would be worth a small consulting fee to make sure you don't waste time and money by not knowing what will end up being meaningful to your users.

 

[CEDEng]

Thanks, Jraef - that was excellent information, and exactly what I was looking for! I should ask them which standard, specifically, they want to meet. That puts the pressure on them, in a way. Ultimately they will likely settle on 508A, and that will be that. Yes, it was guarding and such I was referring to. I have also read good things about TUV in the past, so that was on my short list.

Incidentally, for petersonra, thank you for the input. I'd like to add that after attending some classes and spending lots and lots of money - saying CE is "self-certifying" may be the most costly semantic screw up ever.

Here's a cautionary CE tale (and again, I am anything BUT an expert on it...)

The "self-certifying" part refers to the fact that you "certify" you followed a certain standard(s), and that you can document such. The document can easily run 1000 pages. The test equipment referenced in the document (say, for EMC standards) is just not practical for the average panel shop. While you CAN actually just stick the CE sticker on, if you are called on to verify it in the EU, and cannot, the penalty is tremendous. Odds of being called are slim...unless your competitors give you up.

Twice this year already, I have had shipments held up at the dock in the EU country - not because the CE mark was not on it - it was - but because the list of standards I followed while building it were not part of the shipping document. Technically, they cannot do this - but practically, they absolutely do. I had to fax them my "proof" - and we were in. Without that proof - that machine would still be sitting in limbo.

 

[petersonra]

Incidentally, for petersonra, thank you for the input. I'd like to add that after attending some classes and spending lots and lots of money - saying CE is "self-certifying" may be the most costly semantic screw up ever.

Well, yes and no.

As a practical matter it is probably a good idea for a machine manufacturer to get some help at dealing with CE requirements, at least up front.

However, as a practical matter, the manufacturer is still on the hook even if a third party is involved (with a few exceptions).

Some things are better to just avoid like the EMI requirements. You can either test your machine to prove it meets the requirements or just put a relatively inexpensive EMI filter on the mains and not worry about it.

You can show that MTW wire meets the CE requirements in your technical file, or just use wire that is stamped HAR and also says MTW on it.

 

[CEDEng]

Yep, CE has certainly been a quagmire! We're a bit off the trail of my original problem, but just two more of my cents, we weren't able to avoid the EMI testing. The standard is (fairly) clear about what instruments to measure your emissions with, and which instruments to subject it to, like ESD tests, and so forth - the technical document "documents" that I did these things. Using a proper filter is a means to an end, but does not, in and of itself, satisfy the standard. Instead, a third party does the test with his special room and equipment, gives me his "professional" opinion on the results - and at that point, I "self -certify" that I have met the requirement.

Other standards (as necessary) are somewhat easier to meet without special tools or people, but the EMI is a toughie.

In this regard, the self-certify isn't an option, it's The Way - no one else can do it for you. You pay them to do the tests and provide the data, but in the end (as you said) I am still on the hook, as the manufacturer. That's why I think "self- certify" is, in many cases, underestimated. There's no one else gonna do it for ya!

Thanks again, all, for your input!