Robert, I don't think GFIs are failsafe. Don't they all come with test buttons? Matt
> > Why has no one mentioned using a GFI detector as a "failsafe" way to make > certain the installation is done per spec? > > After all, in the US the manufacturer still comes out liable for any > damages. > > - Robert - > > -----Original Message----- > From: Crabb, John <jo...@exchange.scotland.ncr.com> > To: 'Price, Ed' <ed.pr...@cubic.com>; 'emc-p...@ieee.org' > <emc-p...@ieee.org> > Date: Tuesday, November 16, 1999 3:03 AM > Subject: RE: Grounding Questions > > > > > >Ed, we do not find it necessary to specify an additional ground for our > >Automated Teller Machines, other than the ground provided thru the > >power cord. They are used in similar circumstances to your products. > >We do state in our "site preparation" documents, "WARNING This > >equipment must be earthed". If for any reason the product was not > >grounded, I suspect you would find out quite quickly, since the leakage > >current, although under 3.5 mA, would be noticable !! > >Regards, > >John Crabb, Development Excellence (Product Safety) , > >NCR Financial Solutions Group Ltd., Kingsway West, Dundee, Scotland. DD2 > >3XX > >E-Mail :john.cr...@scotland.ncr.com > >Tel: +44 (0)1382-592289 (direct ). Fax +44 (0)1382-622243. VoicePlus > >6-341-2289. > > > > > >> -----Original Message----- > >> From: Price, Ed [SMTP:ed.pr...@cubic.com] > >> Sent: 15 November 1999 22:12 > >> To: 'emc-p...@ieee.org' > >> Subject: Grounding Questions > >> > >> > >> Hi Listmembers! > >> > >> > >> I have some questions about electrical power feed grounding. > >> > >> One of our divisions makes revenue control equipment (turnstiles, change > >> machines, ticket vending machines) which are installed in rapid transit > >> stations. The physical installation ranges from free concrete floor > >> standing > >> to mounting in a concrete wall alcove. All machines have massive > >> (vandalism > >> problems with cash inside machines) stainless steel housings which the > >> public can and will touch constantly (while standing on possibly wet > >> concrete floors). > >> > >> In the USA, the power for these machines is supplied from a central > >> distribution panel, through conduit, to a surface-mount electrical box > >> equipped with a Twist-Lock style female connector. (All items up to and > >> including the female outlet are customer supplied, and the distance from > >> the > >> distribution panel to the box may be as much as 1500 feet.) The power > >> supplied is 277 VAC, 60 Hz single phase power, in a 3 wire system (third > >> wire is safety ground), with a typical load of about 4 Amps. > >> > >> Should we provide a separate ground stud on our machine case and require > >> the > >> transit district to provide a ground rod at each machine site? Does this > >> present any problems with duplicating the electrical ground which may (or > >> may not) exist at the distribution panel? Can we realistically depend on > >> the > >> third wire ground for safety? If several machines are mounted in a > >> gallery, > >> should we have a ground rod for each machine? > >> > >> Thanks in advance! > >> > >> Ed > > > >--------- > >This message is coming from the emc-pstc discussion list. > >To cancel your subscription, send mail to majord...@ieee.org > >with the single line: "unsubscribe emc-pstc" (without the > >quotes). For help, send mail to ed.pr...@cubic.com, > >jim_bac...@monarch.com, ri...@sdd.hp.com, or > >roger.volgst...@compaq.com (the list administrators). > > > > > > > --------- > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to majord...@ieee.org > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to ed.pr...@cubic.com, > jim_bac...@monarch.com, ri...@sdd.hp.com, or > roger.volgst...@compaq.com (the list administrators). > > > --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
