Zhang Guoqing - I'm not sure where to begin to respond to the below, so I'll limit my responses to the following.
1) §1.4.11 is in §1.4, General conditions for test, and presents an assumption about the nature of telecommunications networks in general. "For the purposes of this standard," is not intended to provide a reference requirement to other standards or to place a specific requirement on the output of a TNV circuit. 2) ETSI and other standards are welcome to reference 60950-1, but this does not always equate to a perfect mapping of 60950-1 into those other standards. 3) The maximum current a circuit is capable of delivering is not necessarily (and typically is not) into a load identical to the Norton equivalent output impedance of the source circuit. 4) TNV circuits output characteristics are evaluated in §2.3. 5) I was a member of the Canada/US BiNational Working Group (BNWG) when the requirement in §6.3 was developed and had input into TC 74 through the TC 74 Chair, who was also a member of the BNWG. The same is true for §1.4.11. 6) If you're interested in further reading, consider UL 1863, which was one of the references used to develop the 1.3 A limit. Regards, Peter Tarver > -----Original Message----- > From: Zhangguoqing (A) [mailto:zhangguoq...@huawei.com] > Sent: Monday, September 16, 2013 19:05 > To: Peter Tarver; EMC-PSTC@LISTSERV.IEEE.ORG > Subject: 答复: [PSES] question on clause 6.3 and 1.4.11 > of IEC60950-1 > > Dear Peter, > > Thanks for your reply. > > For this topic, my opinion is: > ------------------------------------------------------- > ------------------------------------------------------- > ------------------------------------------------------- > ------------------------------------------------------- > ------------------------------------------------------- > ------------------------------------------------------- > ------------------------------------------- > - if it is declared and installed for power > transmission, the power transmit / receive equipment > will be installed by skilled person, and be installed > in pairs. > clause 6.3 should be the requirement for power > transmit equipment, but 15VA should not be the > requirement for power transmit equipment. so, the > power distributed to and available from the > TELECOMMUNICATION NETWORK will be larger than 15 VA. > > - if it is not declared and installed for power > transmission, the power available from a > TELECOMMUNICATION NETWORK is considered to be limited > to 15 VA, and so the equipment connected to the > TELECOMMUNICATION NETWORK > ? does not need to comply with §4.6.4.3 > ? does not need a fire enclosure for the > connectors, per §4.7.2.2, > 7th dashed paragraph > ? does not need a fire enclosure for materials > rated HB75 or HB40 > less flammable (under specified conditions), per > §4.7.2.2, 9th dashed > paragraph, 2nd dotted subparagraph > ? use the connector material exemption in > §4.7.3.3, 3rd paragraph, > 5th dashed subparagraph > ? etc. > ------------------------------------------------------- > ------------------------------------------------------- > ------------------------------------------------------- > ------------------------------------------------------- > ------------------------------------------------------- > ------------------------------------------------------- > ------------------------------------------- > But, in some ETSI standards, 15VA is a limit for power > transmission equipment. The reason for this limit is > interpreted as " according to EN 60950-1 " in those > standards! > For example, this sentence is extracted from clause 4.3 > of ETSI TR 102 614 V1.1.1 (2010-06): > 15 W is the limit according to EN 60950-1 [i.9] for the > power on a telecommunication network and the A4 > interface is > be designed in order to limit the output current to a > value that does not cause damage to the > telecommunication wiring > system due to overheating, under any load condition as > required by the same EN 60950-1 [i.9]. The S/Pfilter > should be > dimensioned for the maximum current of 250 mA at 60 V. > > so, I am confused with this sentence. This email message is for the sole use of the intended recipient(s) and may contain confidential and/or privileged information. If you are not an intended recipient, you may not review, use, copy, disclose or distribute this message. 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