I want to use the RaspberryPI in an industrial environment that requires all devices have UL certification. The RaspberryPI board has UL certification but there is currently no enclosures that are certified. I have been told the UL certification process is expensive and probably beyond the scope of this project.
My questions are:
The Raspberry PI is not UL approved, to the best of my knowledge.
The original intent was not to have any certification done at all since it's essentially a development kit. However, things changed and they were forced to do some EMI and ESD tests to get CE certification , which they successfully did.
They're OK for CE, FCC and C-tick approvals, but not UL. Don't be surprised if UL doesn't want to do a full investigation, including the Pi. You'll likely also have to guarantee that your setup will use an approved power supply for the Pi.
Usually, "UL" certification for industrial control panels refers to UL/ETL 508A Listing or Recognition. There are other organizations that perform compliance testing to the UL/ETL 508A standard, although UL is among the best known (and often the most expensive).
It is not possible to obtain certification to 508A unless all components are Listed or Recognized or a certification/verification is obtained at the assembly level. You can have your industrial control panel and Raspberry PI verified and stickered in compliance with UL-508A as an assembly, provided that your design meets the requirements of the standard.
Generically speaking, it is possible to achieve compliance without every component being UL/ETL recognized if the device consumes less than 200W and is mounted in a Listed enclosure. Check the standard for the fine print. At the end of the day, you'd have an ETL apply a serialized sticker to each panel you make that indicates that it was found to be in compliance with UL/ETL 508A, without having UL certify your panel as a standalone product.
"UL Listing" is only required for components that directly plug into AC Mains, which is why most electronic manufacturers use UL-Listed transformers with their boxes. The box is therefore essentially a low-voltage, dc-powered component and not subject to the UL-listing requirement. Only the transformer has to be UL-listed.
I have a UL certification for the following: Raspberry Pi HMI Touchscreen Panel, Type 4X indoor rating. Here are answers to your questions:
Do I need to UL certify the enclosure for a board that is already certified. No such thing since Raspberry Pi is a low voltage device UL will not certified just the Raspberry Pi or Just an off the shell enclosure.
Can you certify a enclosure without the board inside of it? (So i can pick up a board off the shelf and put the RaspberryPI in it) The answer is no for the same reasons as number one.
How expensive is the UL certification process for an enclosure where the board has already been certified? Cost $10,000-$15,000 to get the UL File Plus ongoing UL Inspection Fees paid once per Quarter and end of year maintenance cost. Around $5000 per year to keep UL Listing.
You can find my information at my website if you are interested in our Raspberry Pi HMI Touchscreen Panel, Type 4X indoor rating:
Uziel Salgado www.kinetic-ia.com