I've seen some motor caps on industrial induction motors whose capacitance gave me pause. I think we specified a minimum bleed down time to allow before servicing. Mike Sherman Graco Inc.
> On 09/29/2020 10:21 PM Ted Eckert > <000007cf6ebeab9d-dmarc-requ...@listserv.ieee.org> wrote: > > > > Hi Rich, > > > I can’t think of many cases of modern IT equipment with a significant > risk of capacitance discharge through the plug. However, I could foresee > motor-driven equipment where it could be an issue. The manufacturer might put > a power factor correction capacitor across the line to compensate for the > inductive load of the motor. The motor should bleed off the charge of the > capacitor, but there may still be some residual charge when the user pulls > the plug. You probably wouldn’t have that large of a capacitor on a > plug-connected motor appliance, but it is possible. > > > It’s been more than a decade since I worked with large motor-drive > appliances, so my memory of their workings isn’t great. I’m sure there is > somebody on this list server who can correct any error I’ve made in my > statements. > > > Ted Eckert > > The opinions expressed are my own and do not necessarily reflect those of > my employer. > > > > > From: MIKE SHERMAN <msherma...@comcast.net> > Sent: Tuesday, September 29, 2020 5:58 PM > To: EMC-PSTC@LISTSERV.IEEE.ORG > Subject: [EXTERNAL] Re: [PSES] electric shock from capacitor discharge > > > Rich -- > > > > Are you including old CRTs as capacitors? I recall that, even with the > early Macs, you had to be careful to discharge the tube if you were going to > mess around inside. > > > > Mike > > > > > > On 09/29/2020 4:27 PM Richard Nute <ri...@ieee.org > > mailto:ri...@ieee.org > wrote: > > > > > > > > > > I am interested in knowing what constructions, situations, and > > products where a capacitive discharge into a body could take place. > > > > I am aware of the X and Y capacitors discharge at the prongs of a > > power plug. I don’t immediately know of other situations or products that > > might discharge a capacitor into a body. > > > > I would appreciate descriptions of such discharges into a body, not > > conjecture. Preferably, normal conditions and some single-fault > > conditions. > > > > Do we need to include capacitive discharge requirements in the > > safety standards? > > > > Stay safe! > > > > Rich > > > > > > - > > ---------------------------------------------------------------- > > > > This message is from the IEEE Product Safety Engineering Society > > emc-pstc discussion list. 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To post a message to the list, send your e-mail to > <emc-p...@ieee.org mailto: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 mailto:sdoug...@ieee.org > > Mike Cantwell <mcantw...@ieee.org mailto:mcantw...@ieee.org > > > For policy questions, send mail to: > Jim Bacher <j.bac...@ieee.org mailto:j.bac...@ieee.org > > David Heald <dhe...@gmail.com mailto: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>
