OK...so this agrees with the other engineer I'm dealing with....the voltage was less than what UL requires for certification. Does anyone have a reference to what that voltage is? Derward wrote: Alan, I recently got approval, for a device, by an agency that requires UL. I used a 12 Volt UL approved wall transformer and the device did hot need UL because all voltages were less than the required buy UL. Derward ----- Original Message ----- From: "alan smith" To: "Microcontroller discussion list - Public." Sent: Monday, April 07, 2008 9:04 AM Subject: Re: [EE] UL question - required for under 24V? > my point exactly. I just wanted some background info before I confronted > this engineer to tell him...he isn't quite right. > > Spehro Pefhany wrote: Quoting alan smith : > >> It was mentioned to be by another engineer that UL testing isn't >> required for those devices that are 24V based systems...and >> essentially 30V falls within that spec as well, and the those >> devices running 48V (such as telcom) are under the same guidelines >> as 120VAC..aka..creepage and clearance. Any truth to what he is >> saying? So what it comes down to is if you have a set of devices >> that are using designed to use PoE (48VDC) they are under a >> different, more stringent testing standard than if I stuck with 24VDC? >> >> I'd like to have a NRTL reference if possible as well. >> >> Thanks in advance > > "Required" by who, exactly? You'll see UL/CSA testing on disk drives, > for example, which are 5V/12V, so the premise is not a reliable one. > > > Best regards, > Spehro Pefhany > -- > "it's the network..." "The Journey is the reward" > s...@interlog.com Info for manufacturers: http://www.trexon.com > Embedded software/hardware/analog Info for designers: http://www.speff.com > > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > > > > --------------------------------- > You rock. That's why Blockbuster's offering you one month of Blockbuster > Total Access, No Cost. > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --------------------------------- You rock. That's why Blockbuster's offering you one month of Blockbuster Total Access, No Cost. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist