More info from PG&E on US grid voltage ranges here <https://www.pge.com/includes/docs/pdfs/mybusiness/customerservice/energystatus/powerquality/voltage_tolerance.pdf> .
On Tue, Apr 11, 2017 at 4:32 AM, Pete Perkins < [email protected]> wrote: > Brian, et al, > > I don't believe that anyone has pointed out that voltage > tolerances are derived from the range that is assigned by the power > utilities - regulated in most developed countries - and needed so that the > national power grid can be interconnected without additional trouble. > > In North America the usual Voltage tolerance is +6/-10% (why > deliver a higher voltage so that the user gets more power for the same > price, but regulate the lower limit so that the user gets a minimum amount > of power for their money). > > Much of the rest of the world uses a Voltage tolerance of +10/-10%. > > So, test houses use these values in testing equipment to ensure > that it will work properly over the usual range of Voltage. > > Designers need to understand this in designing the product but no > need, as has been said, to put this on the product. The nominal voltages > or voltage ranges provided imply that the equipment will work at the > Voltages shown including their tolerances. > > The advent of electronic power supplies on lots of equipment has > simplified the designers life since, in a simple descriptive way, the power > supply is current driven and works independent of the supply Voltage to > provide the needed output. > > :>) br, Pete > > Peter E Perkins, PE > Principal Product Safety & Regulatory Affairs Consultant > PO Box 23427 > Tigard, ORe 97281-3427 > > 503/452-1201 > > [email protected] > > -----Original Message----- > From: Richard Nute [mailto:[email protected]] > Sent: Monday, April 10, 2017 11:18 AM > To: [email protected] > Subject: Re: [PSES] Voltage Rating vs Voltage Specification > > Hi Brian: > > > Is something like this allowed? > > > > 100-115-120/208-220-230-240 > > Unless the applicable standard says otherwise, yes. > > What is the safety issue (injury) that results from non-compliance with > the standard's rules for marking configuration of the input rating? > > > Will a ±10% tolerance always be assumed? > > Usually, yes. > > > If your tolerance > > was something different, such as -15%/+10%, does this information have > > to be on the device or is the manual good enough? > > Your "tolerance" will be used by the certification house if it is greater > than the standard's "tolerance." However, you need not specify the > tolerance. > > The "tolerance" need not be marked on the product; the standard does not > require that you specify a tolerance. So, it is your choice to specify a > tolerance or not, and where to place a tolerance. > > Best regards, > Rich > > - > ---------------------------------------------------------------- > 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]> > > - > ---------------------------------------------------------------- > 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]> > -- Scott Aldous | Regulatory Compliance Program Manager | [email protected] | 650-253-1994 - ---------------------------------------------------------------- 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]>
