Sorry to knock your "substantially built" comment, but the derating is not based on the plug. In fact the 15 and 20 amp plugs are the same construction with different configuration. Both can be used at full rating. The circuit they are used in contains the limitation. The derating on North American circuits is based on thermal considerations. The derating (80% of rated load) applies to all "continuous loads" which are defined as over 3 hours. ITE is considered continuous by default. The long term degradation of wire insulation is related to temperature and time. Given considerations such as neighboring conductors, thermal insulation, current, duration, wire gauge, etc, this is one way the code allows for higher short term loads.
Bob Johnson ITE Safety -----Original Message----- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of John Allen Sent: Thursday, August 29, 2002 5:28 PM To: richwo...@tycoint.com; emc-p...@majordomo.ieee.org Subject: Re: requirements for ITE power cords Hi Folks Sorry to be late in replying on this one - and not really trying to disagree - but I think you will find that the 125% rule is a "North American" convention and also followed by countries which use similar installation practice (i.e. that have plugs with quite small blades/pins!). The same rule does not - to the best of my knowledge - apply in Europe (& certainly not in the UK) and other countries that follow European installation practice where derating is not required as our plugs are more substantially built! Therefore we can use a 13 (UK) or 16A (Europe) cable and 13A or 16A plug on an equipment rated at 13A/16A respectively, e.g: re it applies in respect of the EN60950 standard. Regards John Allen ----- Original Message ----- From: <richwo...@tycoint.com> To: <emc-p...@majordomo.ieee.org> Sent: Thursday, August 15, 2002 11:59 AM Subject: RE: requirements for ITE power cords > > George, the ITE safety standards require that the plug be rated for at least > 125% of the equipment rating. I believe that the US National Electrical Code > has the same requirement. > > Richard Woods > Sensormatic Electronics > Tyco International > > > -----Original Message----- > From: George Stults [mailto:george.stu...@watchguard.com] > Sent: Wednesday, August 14, 2002 6:28 PM > To: 'emc-p...@majordomo.ieee.org' > Subject: requirements for ITE power cords > > > > Hello Group, > > Recently my purchasing department asked me to recommend standards for power > cords. These are detachable power cords for ITE equipment, both 3-wire and > 2-wire. > Typically the cords are marked with one or more of CSA, UL, (Dentori T). > The ones we get are typically rated from 6 to 10 times the required current > for a given product. > > My question is, are there required or recommended power cord design margins > for current, voltage, power, temperature range, insulation, etc. spelled out > in IEC/EN 60950 or UL1950 or MIL-HDBK 217 or elsewhere? > > Thanks in advance > > George Stults > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: emc-p...@hypercom.com > Dave Heald: davehe...@attbi.com > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > http://ieeepstc.mindcruiser.com/ > Click on "browse" and then "emc-pstc mailing list" > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: emc-p...@hypercom.com > Dave Heald: davehe...@attbi.com > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > http://ieeepstc.mindcruiser.com/ > Click on "browse" and then "emc-pstc mailing list" ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
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