We are building a product. It's a bench-top electrical testing thing, similar to a Keithley DMM or an oscilloscope in that it's something engineers would use at companies for testing stuff and occasionally would get built into other equipment.
I would like to incorporate the AC-DC power supply in the chassis so all the user plugs in is a power cable. In other words there would be no need for a wall-wart or desktop power supply.
The big concern is that we would need to get UL (or other NRTL) listed for some of our customers. But what if we purchased a UL listed power supply — something like a PC's power supply with +12, +5, and -12 — and incorporated it. It would bolt into our chassis and only the back side would be exposed to the customer. Could we claim UL listing?
Best Answer
THIS IS ONLY AN OPINION AND IS NOT AUTHORITATIVE IN ANY WAY. THIS DOES NOT CONSTITUTE "ADVICE"
In my past experience, simply using a listed power supply does not grant you immunity from the listing/compliance process.
It is possible that using a fully-enclosed, finger-protected supply like an ATX-style will make your testing extremely easy -- using a wall-wart style would make it even easier -- but I would very much suspect that you can't "claim UL listing" just by using one.
Unlike CE mark, UL, RTL, etc are not self-certifications.