We are getting a somewhat innovative product through UL at the moment. So there has been quite a lot of discussion and feedback from UL. But when UL said they thought my little board needed a pilot rating I really thought they were joking.
Jon Keeble On Fri, Dec 8, 2017 at 8:31 AM, <[email protected]> wrote: > I looked at the subject line and thought about something completely > unrelated – pilot ratings. I have a PP-ASEL IA. Private Pilot – Airplane, > Single Engine, Land Instrument Airplane. 😊 And you? > > > > Ghery S. Pettit > > > > *From:* Jon Keeble [mailto:[email protected]] > *Sent:* Thursday, December 7, 2017 12:29 PM > *To:* [email protected] > *Subject:* [PSES] Pilot rating > > > > I am using a Panasonic AQH3213A PhotoMOS optical isolator to control a > small contactor. > > > > At 110VAC the contactor coil draws 30mArms. > > The coil contacts are wired to a PCB via a terminal block plug and socket. > > > > On the PCB is a series 10ohm fusible resistor, and a SMBJ400AC > bidirectional zener. > > > > When the switch opens at peak current (42mA) there is 0.1J of energy in > the coil that gets absorbed by the zener. > > > > The zener > > * clamps at a voltage way below the voltage rating of the optoMOS switch. > > * is rated at 600W for 8.3msec and is subject to only 13W for a similar > period. > > > > The UL test engineer says that the optoMOS should be "pilot duty" rated > (the part I am using does have this rating). > > > > Does anyone know what triggers the requirement for a "pilot duty" rating? > > Is this defined in a standard somewhere? > > > > This useful link identifies "contact rating codes" > > https://na.industrial.panasonic.com/blog/what-pilot- > duty-rating-how-it-obtained > > > > The lowest rating E300 is for 110V 1.8A (make) 0.3A (break) > > > > Technically speaking, my switch is not connected to the contactor .. there > is a two-component network in between > > Does UL have the capacity or procedures in place to understand and accept > a circtuit analysis that shows my circuit as safe? > > > > Jon Keeble > > > > Wattwatchers. > > > > > > > > - > ---------------------------------------------------------------- > > This message is from the IEEE Product Safety Engineering Society emc-pstc > discussion list. To post a message to the list, send your e-mail to < > [email protected]> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > > Attachments are not permitted but the IEEE PSES Online Communities site at > http://product-compliance.oc.ieee.org/ can be used for graphics (in > well-used formats), large files, etc. > > Website: http://www.ieee-pses.org/ > Instructions: http://www.ieee-pses.org/list.html (including how to > unsubscribe) <http://www.ieee-pses.org/list.html> > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher <[email protected]> > David Heald <[email protected]> > - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
