IEEE C62.39-2012 pdf free download.IEEE Standard for Test Methods and Preferred Values for Self-Restoring Current-Limiter Components Used in Telecommunication Surge Protection.
1.2 Purpose The test criteria and terms of this standard provide a means of component comparison and a common engineering language for users and manufacturers of self-restoring current-limiter components intended for use in low-voltage telecommunication circuit surge protection. The test and measurement of low-voltage telecommunication (data, communications, and signalling) surge protectors is given in IEEE Std C62.36™ [B6]. 1 This standard provides the corresponding component tests for the surge protector non-surge and active tests. 2. Definitions and acronyms 2.1 Definitions For the purposes of this document, the following terms and definitions apply. The IEEE Standards Dictionary Online should be consulted for terms not defined in this clause. 2 electronic current limiter (ECL): Assembly of one or more electronic components that automatically restricts the current amplitude when it exceeds a predetermined threshold level. NOTE—See Recommendation ITU-T K.82 [B10]. 3 endurance test (life test) ac: Application of a specified number of trip events under specified temperature and trip cycle (on and off time) conditions. NOTE—See Recommendation ITU-T K.82 [B10]. endurance test (life test) impulse: Application of a specified number of impulses under specified temperature and impulse repetition rate conditions. NOTE—See Recommendation ITU-T K.82 [B10]. fault current, I fault : Current used when measuring time-to-trip. NOTE 1— Specific values of I fault used are 1 A and 5 × I h . NOTE 2— Modified from IEC 62319-1:2005 [B4].
hold current, I h : Maximum current at specified ambient temperature, which will not cause the trip event. NOTE 1— Sometimes known as rated or non-tripping current. NOTE 2— See IEC 62319-1:2005 [B4]. impulse generator charge voltage, V C : Voltage value of the impulse generator’s energy storage capacitor immediately before delivering an impulse. impulse resistance [ceramic positive temperature coefficient (CPTC) thermistor], R imp : Quotient of the peak impulse voltage between the terminals by the peak impulse current through the PTC thermistor. NOTE 1— CPTC thermistors are also voltage-dependent resistors and conduct higher currents (up to three times) under impulse conditions than predicted from the untripped resistance value. NOTE 2— See Recommendation ITU-T K.82 [B10]. impulse voltage, V imp : Value of peak impulse voltage. NOTE 1— V imp is the overcurrent protector (OCP) impulse voltage. V impmax is the maximum limiting voltage of the voltage limiter protecting the OCP. NOTE 2— See Recommendation ITU-T K.82 [B10]. maximum current ac, I max : Value of current for the operating temperature range, which should not be exceeded. NOTE—Modified from IEC 62319-1:2005 [B4]. maximum voltage ac, V max : Maximum ac voltage that may be applied. NOTE—Modified from IEC 62319-1:2005 [B4]. overcurrent protector (OCP): Series connected component that causes currents exceeding a predetermined value to be restricted. NOTE 1— The acronym OCP is used in this standard specifically for the current-limiter components covered in the Scope. NOTE 2— Modified from IEC 62319-1:2005 [B4].
positive temperature coefficient (PTC) thermistor: Thermistor in which the resistance increases with increasing temperature throughout the useful part of its characteristic. NOTE 1— The PTC thermistors covered in this standard exhibit a very sharp increase in resistance over a narrow temperature range. NOTE 2— In this standard the change of temperature that results in resistance increase is caused by the current flow through the PTC thermistor. NOTE 3— Modified from IEC 62319-1:2005 [B4]. preferred values: The parameters listed for various tests are preferred in the sense that their use promotes uniformity. However, specific applications may require values other than the listed preferred values. NOTE—See IEEE Std C62.34™-1996 [B5]. reset voltage, electronic current limiter (ECL), V reset : Value of dc voltage at which there is a transition from a high-resistance tripped state to a low-resistance untripped state.
www.findfreestandards.com