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 <emc-p...@ieee.org> 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 <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
