* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download TIA-968-A leakage question - Telecommunications Industry
History of electric power transmission wikipedia , lookup
Electrical substation wikipedia , lookup
Current source wikipedia , lookup
Switched-mode power supply wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Opto-isolator wikipedia , lookup
Telecommunications engineering wikipedia , lookup
Buck converter wikipedia , lookup
Electromagnetic compatibility wikipedia , lookup
Ground loop (electricity) wikipedia , lookup
Automatic test equipment wikipedia , lookup
Voltage optimisation wikipedia , lookup
Alternating current wikipedia , lookup
Stray voltage wikipedia , lookup
Portable appliance testing wikipedia , lookup
Ground (electricity) wikipedia , lookup
Surge protector wikipedia , lookup
TR41.9-07-11-005 Title: TIA-968-A leakage current question Distribution to: TIA TR41.9 Meeting Location: Albuquerque, NM Novemeber, 2007 Submitting Littelfuse Organization: Contact Phillip Havens Information: Littelfuse 1800 Hurd Drive Irving, TX 75038 Phone (972) 518-9427 Fax (972) 550-1309 Email : [email protected] Keywords: TIA-968-A NOTICE: The contributor grants a free, irrevocable license to the Telecommunications Industry Association (TIA) to incorporate text or other copyrightable material contained in this contribution and any modifications thereof in the creation of a TIA Publication; to copyright and sell in TIA's name any TIA Publication even though it may include all or portions of this contribution; and at TIA's sole discretion to permit others to reproduce in whole or in part such contribution or the resulting TIA Publication. This contributor will also be willing to grant licenses under such copyrights to third parties on reasonable, non-discriminatory terms and conditions for purpose of practicing a TIA Publication which incorporates this contribution. This document has been prepared by Littelfuse to assist the TIA Engineering Committee. It is proposed to the Committee as a basis for discussion and is not to be construed as a binding proposal on Littelfuse. Littelfuse specifically reserves the right to amend or modify the material contained herein and nothing herein shall be construed as conferring or offering licenses or rights with respect to any intellectual property of Littelfuse other than provided in the copyright statement above. TR41.9-07-11-005 TIA-968-A contains the following paragraphs: Note 4 to table 4.1 A telephone connection, auxiliary lead, or E&M lead that has an intentional dc conducting path to earth ground for protection purposes at the leakage current test voltages (such as through a surge suppressor), may have the component providing the conducting path removed from the equipment for the leakage current test in that operational state. Components removed for this reason shall comply with the requirements of section 4.4.5.2. 4.4.5.2 Connections with protection paths to ground. Approved terminal equipment and protective circuitry having an intentional dc conducting path to earth ground for protection purposes at the leakage current test voltage that was removed during the leakage current test of section 4.3 shall, upon its replacement, have a 50 or 60 Hz voltage source applied between the following points: a) Simplexed telephone connections, including tip and ring, tip-1 and ring-1, E&M leads and auxiliary leads, and; b) Earth grounding connections. The voltage shall be gradually increased from zero to 120 V rms for approved terminal equipment, or 300 V rms for protective circuitry, then maintained for one minute. The current between (a) and (b) shall not exceed 10 mAP at any time. As an alternative to carrying out this test on the complete equipment or device, the test may be carried out separately on components, subassemblies, and simulated circuits, outside the unit, provided that the test results would be representative of the results of testing the complete unit. 1) Why is the voltage level restricted to 120 V rms for approved terminal equipment but then increased to 300V rms for protective circuitry? What are the technical details that push for these two different voltage levels? 2) What is the definition of “protective circuitry”? 3) How does one distinguish between approved terminal equipment and protective circuitry? (Isn’t protective circuitry found in terminal equipment?)