I am building a device for internal use in my company’s retail locations. It is a low voltage device powered by a U.L. listed power supply (basically a laptop brick). Max voltage inside the device is 19 Volts and it is all metal and basically (but not completely) airtight.
Does my device itself need to be U.L. listed for insurance or other regulatory purposes?
I may be vastly oversimplifying this, as is often the case when asking about regulations…
FWIW, power supply (19V) is rated at 65W and the device, under normal load, will consume far less than that.
Hey! I used to work for CSA (UL’s direct competitor) as a certification engineer! Note that the below is a gross oversimplification and that I am not liable if you take my advice below and I happen to be mistaken or forget anything.
So basically the rule of thumb is that you would want the device to be evaluated for listing if:
The reason you want a listing for any of the above reasons is mostly for liability and insurance purposes. The thing to remember is that in most geographical areas there’s no legal requirement for devices to have an NRTL mark (Nationally Recognized Testing Laboratory, i.e. UL, CSA, ETL, FM, etc.), but you will be liable if something dangerous happens and certain regulatory bodies specific to your use case (and OSHA) might require it.
Also, outside of extenuating circumstances like Hazardous Locations there is no legal requirement for you to go with one NRTL over any other NRTL. UL is the best known NRTL in the US, but you’ll get different pricing and timelines for your evaluations depending on the NRTL.
Since it sounds like this device is going into multiple retail locations and may or may not be serviced by personnel who are familiar with it my advice would be to check with your legal and safety teams to determine the best action. Since its a low power device it shouldn’t take too much time for evaluation to get it certified, but its not cheap.
Ultimately certification is a sticky, sticky field that has a lot of ifs, ands, and buts to it. My engineering brain tells me that with a certified power supply a low power device like this should be perfectly safe, but its still going to fall to you and your company to determine if you are willing to accept the risk/liability and to determine any regulatory bodies specific to your situation.
Edit: I forgot to mention. One thing about certification that most people don’t know is that when you contract an NRTL to evaluate your product what you’re actually paying for is for an engineer to evaluate your product to the applicable standards. There is absolutely no guarantee that your product will pass certification and in many, many cases unless your product was designed with the applicable standards in mind it might be difficult for your product to pass. I don’t mean to sound discouraging but rather to give you a realistic picture. You wouldn’t believe how many times certification engineers are verbally abused and physically threatened and/or harassed by clients because they didn’t understand what they were actually paying for and their product didn’t meet the requirement of the standards.
Its not about whether or not your product is safe, its whether or not it meets the standards. Theoretically the standard is supposed to be written to ensure safety, but believe it or not the standards committees are made up of representatives in industry. So, for example, with Industrial Control standards you can bet your ass that representatives from Fluke, GE, Siemens, Allen Bradley, and hundreds if not thousands of other big name companies are all on the committee and get a say in what ends up in the standard and exactly how the clauses are worded.
@BarkingChicken, thanks so much for your reply.
Yikes. This thing is going to be “controlling” fuel pumps, though not directly. It is going to be processing credit card payments and subsequently enabling the pump, though indirectly by communicating with a computer in the pump itself.
What kind of person / firm would I hire to determine whether certification is needed at all?
Thanks again!
Ah. That complicates things because I’m not actually sure what the Hazloc requirements for that are. I don’t think your product would be considered to be in a hazardous location unless it’s physically in the fuel tank, but because it’s controlling something in a fuel tank it’s kind of a grey area.
If you contact the NRTL directly their sales engineers can usually give you a good idea of what’s required. Alternately, there are several fourth party firms out there that can help with determining what regulatory bodies and standards are applicable. NTS out of Plano is the only one I know by name.
CSA actually has a Hazardous Locations office in Plano, and if you’d like I can put you in contact with one of their technical sales engineers. I worked with this guy for 4 years and can personally vouch for the fact that not only does he know his stuff but also he won’t bullshit you into paying something you don’t need.
I also used to be a Certification Engineer, but at UL. @BarkingChicken just gave you some very sound advice. Suggest you follow her lead.
That device is not really “controlling” the pump. It is enabling the pump. The safety controls, auto stop, emergency stop, etc., are built into the pump. The worst thing that device could do is give someone free gas. The device likely does not require UL certification but it does require FCC cert since it is being installed in a commercial location. My advice is to build a compete prototype with software, then pay an engineering company to redesign the hardware as needed, design the enclosure, and get all the relevant certifications.
Please try to figure out how to take security to the next level. It would be great to make skimmers anywhere in the pump enclosure unable to get the card #, PIN, or ZIP code.
It’s my understanding the FCC is fairly easy to avoid by keeping the processor clock frequency (all clocks) below 1 MHz and not including a radio of any kind. The flashlight in my pocket is a good example. It uses “high frequency” PWM to control the light level of the LED but does not have an FCC certification.
To keep your UL Safety Certification investigation as inexpensive as possible I stongly suggest that you provide a brick power supply that has an LPS Certification. Check out LPS Power Supplies. An LPS rated power supply is already pre-tested for safety in the event that the output pulls excessive current, even a short circuit, and limits any over voltages to acceptable values. Any potential safety fault in your connected equipment will be taken care of within the external LPS rated power supply. This will limit the safety concerns of your project to hazardous area issues, not electrical. Good luck on your project.
@kbraby, this isn’t going to be built into the dispenser itself. It’s just a device (a PC and a bunch of related circuitry) that sits in a back office. It’s connected to the dispensers but has nothing to do with the card reading hardware.
@richmeyer, is that something in addition to using a UL listed power supply? Plan was to use an Intel NUC motherboard and use the same brick (laptop style) that they use.
@BarkingChicken, Shay, I would appreciate that introduction. My work email is matt decimal redmond at 7-11 decimal com.
Thanks!
Matt
The Power Supply is still UL Listed but also has an LPS mark on it. If you look at your laptop computer, the computer itself does not have a UL Listing but the brick power supply usually has the UL Listing and LPS marking.
Even though I used to work for UL, I would strongly suggest you use the ETL Label since you are located in the Dallas area. ETL and UL are just competitors of each other. ETL has a local office in Plano named Intertek and they are fully staffed to handle your project. UL also has an office in Plano but they would have to send your project to Chicago. It would be cheaper for you with ETL. Call Intertek and ask for Tracy Havlik (in sales), she knows me very well.
Cool I used to work for CSA too back in the 90s in Richmond BC
I used to work directly adjacent to an ETL office in Dallas off of Indian Trail. But they’re Environmental Testing Laboratory, not the UL competitor - vibration, pressure, acceleration, temperature, radiation testing, and the like.
I have tested at both facilities. You are correct about Environmental Test Laboratory (the other ETL) on Indian Trail (Royal Lane near I-35). The company I was talking about is named Intertek, in Plano (1/4 mile East of Fry’s Electronics). Intertek will test per the UL and European Standards and apply the ETL Safety Mark, similar to Underwriters Laboratory applying the UL Safety Mark. A lot of people in the Dallas/Fort Worth area get these two names confused. ETL is a Dallas company and ETL is an internationally acclaimed Safety Mark.
Edit: Sorry, I gave the wrong location of Intertek. It is in Plano on 10th Street just west of Jupiter Road. The building is hard to find, it is behind the Verizon warehouse. Hey, I was only a 1/2 mile off.
I’ll send over your contact information.
If any product is used in the US it has to comply with US FCC regulations. FCC does not test or label products the manufacturer is responsible to ensure the product is in compliance with all FCC regulations (EMI. RFI, etc.) FDA has the regs on optical limits. I have seen many electrical products fail FCC regs with no digital circuits inside at all. see CFR 47