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, <n6...@comcast.net> 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:j...@wattwatchers.com.au]
> *Sent:* Thursday, December 7, 2017 12:29 PM
> *To:* EMC-PSTC@LISTSERV.IEEE.ORG
> *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 <
> 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) <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 <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>
>

-
----------------------------------------------------------------
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>

Reply via email to