Working Cover Page by Zspa7BT

VIEWS: 4 PAGES: 32

									                                                                     TR41.7-09-08-005-2564-AppGuidev5.0
     PN-3-0340-RV4 to be published as TIA/TSB187

1                                             Document Cover Sheet
2
     Project Number       PN-3-0340-RV4 to be published as TIA/TSB187

     Document Title       UL Subject 2564 Outline of Investigation for Low-Voltage Surge
                          Withstand
                          Telecommunications Overcurrent Protector Components
                          Application Guide
                          Draft 5.0 (2009-05-06)
     Source               TR41.7.5

     Contact              TR41.7 Chairman – Randy Ivans              Phone: 631-546-2269
                          1285 Walt Whitman Rd.                      Fax:
                          Melville, NY 11747                         Email: Randolph.j.ivans@us.ul.com

     Distribution         TR41.7 / TR-41.7.1 / TR41.7.5
     Intended Purpose      X     For Incorporation Into TIA Publication
     of Document                 For Information
     (Select one)                Other (describe) -
     The document to which this cover statement is attached is submitted to a Formulating Group or
     sub-element thereof of the Telecommunications Industry Association (TIA) in accordance with the
     provisions of Sections 6.4.1–6.4.6 inclusive of the TIA Engineering Manual dated March 2005, all of
     which provisions are hereby incorporated by reference.

3
4
 5
 6   Abstract
 7   This draft of the application guide for UL Subject 2564 was completed by the TR41.7.5
 8   WG at the May Indianapolis meeting. It is for review and comment with final review
 9   expected at the November 2009 TR41.7 meeting.
10
11




                                                       i
                                                              TR41.7-09-08-005-2564-AppGuidev5.0
     PN-3-0340-RV4 to be published as TIA/TSB187

 1                                       Working Cover Page
 2
 3
 4                         UL Subject 2564 Outline of Investigation for
 5                              Low-Voltage Surge Withstand
 6                   Telecommunications Overcurrent Protector Components
 7
 8                                     Application Guide
 9
10
11                                             Draft 5.0
12                                           (2009-05-06)
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29      Warning: This Document is a “work in progress” by TIA TR41.7.5 and as such it’s
30                                  contents may change.




                                                   i
                                              PN-3-0340-RV4 to be published as TIA/TSB187


 1   FOREWORD
 2
 3   This Document is a TIA Telecommunications Systems Bulletin (TSB), produced by
 4   Working Group TR-41.7.5 under subcommittee TR-41.7 of Engineering Committee TR-
 5   41, User Premises Telecommunications Requirements, under the sponsorship of the
 6   Telecommunications Industry Association [TIA]. Telecommunications Systems Bulletins
 7   are not standards and are distinguished from TIA Standards in that TSBs contain a
 8   compilation of engineering data or information useful to the technical community and
 9   represent approaches to good engineering practices suggested by formulating group
10   TR-41.7.
11
12   This Bulletin is not intended to preclude or discourage other approaches which similarly
13   represent good engineering practice, or which may be acceptable to, or have been
14   accepted by, appropriate bodies such as the Federal Communications Commission
15   [FCC]. Parties who wish other approaches to be considered for inclusion in future
16   revisions of this Bulletin are encouraged to bring them to the attention of the formulating
17   group TR41.7. It is the intention of thise formulating group to revise and update this
18   TSBBulletin from time to time as may be occasioned by changes in technology, industry
19   practice, government regulations, technical criteria, or other appropriate reasons.
20
21   This Document offers enhancements and clarifications for the technical criteria
22   contained in the following documents:
23   UL SUBJECT 2564 - OUTLINE OF INVESTIGATION FOR LOW-VOLTAGE SURGE WITHSTAND
24   TELECOMMUNICATIONS OVERCURRENT PROTECTOR COMPONENTS
25          UL 2564 Outline of Investigation, Issue 2
26
27
28




                                                  i
                                           PN-3-0340-RV4 to be published as TIA/TSB187


1   TR-41.7 MEMBERS AND TSB-187 CONTRIBUTORS
2   People on this list either where a voting member of TR41.7 at the time this document
3   was voted to publication or made contributions to the development of this document.
4
5   SEE TIA OPERATIONAL GUIDELINES Version 1.4
6

    Organization Represented                   Name of Representative
     ADTRAN, Inc                                Bell, Larry
     Bourns Ltd.                                Maytum, Michael
     Cisco Systems                              Lawler, Tim
     Cooper Bussmann Inc.                       Giblin, Dan
     Embarq                                     Ray, Amar
     Bournes Ltd.Fultec Semiconductor Inc.      Wiener, Paul
     Hewlett-Packard                            Roleson, Scott
     Littelfuse Inc.                            Havens, Phillip
     Mobile Engineering                         Bipes, John
     Sanmina - SCI                              Tarver, Peter L.
     SOC America Inc.                           Lindquist, Carl
     Telcordia Technologies                     McCarver, Randall
     Thomson Inc.                               Hunt, Roger
     Tyco Electronics                           Martin,Al
     Underwriters Labs                          Ivans, Randy
     Underwriters Labs                          Ladonne, Frank
     Verizon                                    Bishop, Trone
     Vtech Engineering                          Whitesell, Steve

7




                                               ii
                                                                                PN-3-0340-RV4 to be published as TIA/TSB187


1                                                                           CONTENTS
2    FOREWORD ......................................................................................................................................................... I

3    TR-41.7 MEMBERS AND TSB-187 CONTRIBUTORS ...................................................................................... II

4    CONTENTS ....................................................................................................................................................... III

5    LIST OF FIGURES ..............................................................................................................................................IV

6    1                    INTRODUCTION ........................................................................................................................... 5

7    2                    SCOPE........................................................................................................................................... 6

8    3                    REFERENCES .............................................................................................................................. 7

9    4                    DEFINITIONS, ACRONYMS AND ABBREVIATIONS ................................................................. 7

10   5                    SERVICE ENVIRONMENT CONDITIONS ................................................................................. 11
11            5.1         Temperature ................................................................................................................... 11
12            5.2         Surge Current ................................................................................................................. 12

13   6                    CLASSIFICATIONS................................................................................................................. 1615
14            6.2         Voltage Groups ........................................................................................................... 1615

15   7                    KEY PARAMETERS................................................................................................................ 1716
16            7.3         Maximum limited duration voltage rating ................................................................... 1816

17   8                    MARKING ................................................................................................................................ 2018

18   9                    TEMPLATES............................................................................................................................ 2119
19            9.1         Template rationale ...................................................................................................... 2119
20            9.2         Template application .................................................................................................. 2119

21   EXAMPLE: SUBJECT 2564, FIGURE A1 – TEMPLATE A .......................................................................... 2220
22            9.3         Template temperature correction ...............................................................................2220

23   10                   TEST SEQUENCE FLOW CHART ......................................................................................... 2321

24   11                   EQUIPMENT STANDARDS.................................................................................................... 2321

25   12                   PARTS ..................................................................................................................................... 2321
26            12.1 Part 1 is the main portion of Subject 2564. It provides all the testing procedures and
27            requirements for meeting this standard................................................................................. 2321
28            12.2        Parts 2 through 5 ........................................................................................................ 2321
29
30




                                                                                      iii
                                             PN-3-0340-RV4 to be published as TIA/TSB187


1                                        LIST OF FIGURES
2   No table of figures entries found.
3
4




                                               iv
                                            PN-3-0340-RV4 to be published as TIA/TSB187


1

2    1   INTRODUCTION

 3   UL Subject 2564 provides safety requirements for several different technologies that
 4   can be employed to protect against excessive current. Each protector technology has
 5   unique current protection characteristics. Subject 2564 Templates reflect the time-
 6   current characteristics of overcurrent protectors for specific equipment
 7   telecommunication standards. Characteristics of each type protector are provided using
 8   “Current-Time Templates”, “Voltage Groups”, “Categories” and Environmental
 9   “Classes” in order to characterize different technologies that may be employed for
10   meeting these requirements. Physical size and shape have not been standardized or
11   established in this document.

12   Overcurrent protectors covered in this Application Guide are intended for wire line
13   paired cable telecommunications ports, including Ethernet. Some, such as fuses and
14   Line Feed Resistors (LFR) are non-resettable, while others, such as Polymer or
15   Ceramic Positive Temperature Coefficient (PTC) Protectors and Electronic Current
16   Limiters (ECL’s) are resettable. Since each technology has its own strengths and
17   weaknesses, they must be evaluated carefully for each application.

18   Protector current ratings have been eliminated in favor of current-time templates
19   showing ACCEPTABLE and UNACCEPTABLE Regions. Voltage ratings are replaced
20   with Voltage Groups (VG). Specific environmental conditions are captured in
21   Environmental Classes. For a given application, a Template, Voltage Group,
22   Environmental Class and Category should be predetermined.
23
24




                                               5
                                               PN-3-0340-RV4 to be published as TIA/TSB187


1

 2   2   SCOPE
 3
 4   This guide has been prepared to aid in the use and understanding of UL Subject 2564
 5   “Outline of Investigation Low-Voltage Surge Withstand Telecommunications
 6   Overcurrent Protector Components”. This includes associated Parts covering specific
 7   overcurrent technologies. The overcurrent protectors covered withstandare lightning
 8   surges resilient, yet will safely interrupt or reduce overload current when itcurrent from
 9   outside sources exceeds current levels deemed safe for equipment and wire. This
10   guide willonly covers only protectors intended for applications described in UL Subject
11   2564.




                                                  6
                                              PN-3-0340-RV4 to be published as TIA/TSB187


1

 2   3   REFERENCES
 3
 4   The following documents contain provisions that may be useful in applying these
 5   guidelines and carrying out the recommended test procedures and guidelines for
 6   determining compliance with UL 2564provided in this document. At the time of
 7   publication, the editions indicated were valid. All documents are subject to revision, and
 8   parties to agreements based on this Ddocument are encouraged to investigate the
 9   possibilitiesy of applying the most recent published editions of the documents. published
10   by them.
11
12   1. ANSI/TIA-968-A (2002), Telecommunications – Telephone Terminal Equipment -
13      Technical Requirements for Connection of Terminal Equipment to the Telephone
14      Network
15   2. ANSI/TIA-968-A-1 (2003), Telecommunications – Telephone Terminal Equipment -
16      Technical Requirements for Connection of Terminal Equipment to the Telephone
17      Network
18   3. ANSI/TIA-968-A-2 (2004), Telecommunications – Telephone Terminal Equipment -
19      Technical Requirements for Connection of Terminal Equipment to the Telephone
20      Network
21   4. ANSI/TIA-968-A-3 (2005), Telecommunications – Telephone Terminal Equipment -
22      Technical Requirements for Connection of Terminal Equipment to the Telephone
23      Network
24   5. ANSI/TIA-968-A-4 (2006), Telecommunications – Telephone Terminal Equipment -
25      Technical Requirements for Connection of Terminal Equipment to the Telephone
26      Network
27   6. Telcordia GR 1089, Issue 4, Electromagnetic Compatibility and Electrical Safety –
28      Generic Criteria for Network Telecommunications Equipment.
29   7. UL 497A, Secondary Protectors For Communication Circuits
30   8. UL 1459, Third Edition, Telephone Equipment
31   9. UL 60950-1 Second Edition, Safety of Information Technology Equipment
32

33   4   DEFINITIONS, ACRONYMS AND ABBREVIATIONS
34
35   Refer to UL Subject 2564 for definitions of terms used in that document. For the
36   purposes of this Ddocument, the following definitions apply:
37


                                                 7
                                                    PN-3-0340-RV4 to be published as TIA/TSB187

 1   Ceramic Positive Temperature Coefficient (CPTC) Thermistor (CPTC)
 2
 3   A thermistor constructed of ceramic semiconductor material, which exhibits a step-like
 4   increase of a factor of 100 or more in resistance with increasing temperature.
 5
 6   Note: CPTC thermistors covered by this document are intended for use as current limiting protection
 7   elements.
 8
 9   Current Interruption
10
11   The act of reducing current to a predetermined level, or zero, to protect a circuit and its
12   components.
13
14   Current Limiter
15
16   Non-linear device that automatically restricts the value of current when the current
17   attempts to exceed a given value for a sufficient time
18
19   Design Template
20
21   Specific description, including use, associated equipment standard, current limiting level
22   and surge withstand capabilities.
23
24   DUT
25
26   Abbreviation - Device Under Test
27
28   Electronic Current Limiter (ECL)
29
30   Protection device which electronically limits currents above a specific threshold current.
31
32   Fire Enclosure
33
34   A part of the equipment intended to minimize the spread of fire or flames from within.
35
36   Fuse
37
38   A protective device which opens a circuit during specified overcurrent conditions by
39   means of a current responsive element.
40
41   Fusing Resistor
42
43   A resistor intended to interrupt a current flow at a predetermined time when the

                                                        8
                                                     PN-3-0340-RV4 to be published as TIA/TSB187


 1   current passing through it exceeds a predetermined value.
 2
 3   Note: A Fusing Resistor is intended to be replaced following operation.
 4
 5   Hold current (Ih)
 6
 7   See Maximum continuous current.
 8
 9   Limited duration current
10
11   Applied current for a known maximum time period.
12
13   NOTE: For this standard, limited duration time periods will be either 1.5 second or 5 seconds, maximum.
14
15   Line Feed Resistor (LFR)
16
17   A fusing resistor used for AC overcurrent protection of telecommunications circuits.
18
19   NOTE: An LFR may incorporate multiple resistive elements, thermal links, which melt and limit the
20   maximum long-term temperature rise, and PTC thermistor elements to give a self-restoring function at low
21   levels of AC. After fusing, the LFR has a permanent increase of resistance value exceeding 100 times the
22   original resistance.
23
24   Maximum continuous current (Imco) [Sometimes referred to as Hold current (Ih)]
25
26   Highest current that may be conducted by the protector without operation or permanent
27   degradation at specified ambient temperature.
28
29   Maximum continuous operating voltage (Vmco)
30
31   Maximum continuous DC source voltage of the circuit in which the protector will be
32   installed.
33
34   Note: This term ignores telecommunications alerting signals.
35
36   Maximum limited duration fault current (Ildf)
37
38   The highest prospective rms symmetrical alternating current that a protector will safely
39   interrupt under specified conditions and for the defined duration at the maximum limited-
40   duration voltage (Vmld) and is the highest value shown in the appropriate current-time
41   template.
42
43   Maximum limited duration voltage (Vmld)


                                                         9
                                                   PN-3-0340-RV4 to be published as TIA/TSB187


 1
 2   Maximum rms symmetrical alternating voltage to which the protector will be subjected
 3   during fault conditions for a specified minimum time duration.
 4   NOTE 1: Maximum limited duration voltage (Vmld) is typically greater than Maximum continuous operating
 5   voltage (Vmco).
 6   NOTE 2: Typically, the minimum specified fault duration is either 1.5 or 5 seconds.
 7   NOTE 3: Maximum limited duration voltage (Vmld) is selected from the Voltage Group associated with a
 8   given Template.
 9
10   Maximum test duration time (ts)
11
12   Maximum time for application of a test current or voltage.
13
14   Microclimate
15
16   Immediate environment of the device.
17
18   Polymer Positive Temperature Coefficient (PPTC) Thermistor (PPTC)
19
20   A thermistor constructed of polymeric composite material, which exhibits a step-like
21   increase of a factor of 100 or more in resistance with increasing temperature.
22
23   Note: PPTC thermistors covered by this document are intended for use as current limiting protection
24   elements
25
26   Prospective current
27
28   Current thatwhich would flow at a given location in a circuit if it were short-circuited at
29   that location by a link of negligible impedance.
30
31   Surge Current
32   A transient current thatwhich rises rapidly to a peak value and then falls more slowly to
33   zero.
34
35   Surge Current (Impulse) Withstand Rating
36
37   Maximum current surge waveform the DUT will safely withstand without loss of function
38   after repeated predefined current surge impulses.
39
40   Surge Voltage
41
42   A transient voltage thatwhich rises rapidly to a peak value and then falls more slowly to
43   zero.
44


                                                      10
                                             PN-3-0340-RV4 to be published as TIA/TSB187

1    Trip Current (It)
2
3    Lowest current thatwhich will cause the thermistor to trip to a high resistance condition
4    at a specified temperature (preferably 23°C) and within a time to be specified.

5

 6   5     Service Environment Conditions
 7
 8   The service environment is a combination of the electromagnetic environment and the
 9   ambient environment local to the component (microclimate). Depending on the
10   component sensitivity, it is assessed either at an environmental parameter extreme or
11   the parameter extremes, possibly with additional testing being done at a reference
12   value.
13
14   The electrical assessment normally concentrates on surge testing, as it is the highest
15   electromagnetic environment stress.
16   The common ambient environmental parameters are temperature, humidity and air
17   pressure. For these components, temperature is considered the main ambient
18   environmental sensitivity. In special cases, other ambient environmental parameters
19   such as; vibration, mechanical shock, contaminants and condensation, may need to be
20   considered.
21   5.1    Temperature
22
23   These components will normally be mounted inside an equipment enclosure. Being
24   inside the equipment enclosure means that the component local ambient temperature
25   may not be the same as the local ambient temperature surrounding the equipment. The
26   equipment design may set the internal temperature (microclimate) by using natural
27   cooling, forced air-cooling or some form of local temperature control. The most severe
28   ambient temperature condition is normally for natural cooling.
29
30   For natural cooling the lowest microclimate temperature will be the same as the lowest
31   ambient temperature surrounding the equipment. The highest microclimate temperature
32   will be the highest ambient temperature surrounding the equipment plus the internal
33   temperature rise inside the equipment enclosure. The component temperature range
34   must be based on these parameters.the same as the equipment’s temperature range
35   with a higher maximum temperature.
36
37   Equipment locations using temperature control have a typical ambient range of 5 °C to
38   40 °C. The corresponding controlled microclimate temperature range is 5 °C to 70 °C.


                                                11
                                              PN-3-0340-RV4 to be published as TIA/TSB187


1    Equipment locations with uncontrolled temperature have a typical ambient range of -
2    40 °C to 70 °C. The corresponding uncontrolled microclimate temperature range is -
3    40 °C to 85 °C. Manufacturers may define special microclimates with different maximum
4    and minimum temperature values to cover non-standard microclimates.
5    5.2   Surge Current
 6   Surges result from AC supply power faults and nearby lightning strikes.
 7   The local surge environment is the result of many factors includingsuch as the
 8   equipment location and installation conditions. : premises, type of installation
 9   and location. Equipment Standards tend to classify by premises first, such as
10   Central Office or Customer premises, then by installation type. Severe surge
11   environments are covered by higher-level surges.
12
13   Surges result from AC supply power faults and lightning. AC supply power fault testing
14   is done with 120 V AC to simulate contact to the normal mains supply and at levels up
15   to 600 V AC for faults from higher voltage AC lines. Testing is done at various short-
16   circuit current levels and times. Lightning surge testing has to comprehend a wide range
17   of circumstances. Besides the surge being delivered directly from the communications
18   line, tests are made to simulate the inductive voltage drop in the primary protector
19   ground wire (2/10 surge) and for primary-secondary protector coordination.
20
21   5.3    AC Power Fault Surges
22   AC power fault testing is conducted with voltages to simulate contact to a mains supply
23   operating at 120/240 V, 120/208 V 3 phase-Y or 277/480 V 3 phase-Y. Testing is also
24   conducted at levels up to 600 V AC for contact or induction faults from higher voltage
25   AC lines, limited by a primary protector. Testing is done at various short-circuit current
26   magnitudes and durations.
27
28   Table 1 below lists the various generator capabilities used for AC power fault testing.
29   The table rows are arrangedby reference document, by open-circuit voltage, and then
30   by short-circuit current and reference document. The reference document column gives
31   the reference document, the test clause and any table test reference. The open-circuit
32   voltage column has rows of decreasing voltage and the short-circuit column has rows of
33   decreasing (maximum) current.
34
35   Even though Table 1 has 10multiple generator test capabilitiesy identified rows. This
36   doesn’t mean 10 separate AC generators are not necessarily required. A as a single
37   generator can be designed to provide the required capability for multiple rows. For
38   example, a generator with a variable voltage up to 600 V AC,and a current capability
39   ofup to 60 A AC per line (for up to two line devices, respectively) for the test time


                                                 12
                                             PN-3-0340-RV4 to be published as TIA/TSB187


1   specifiedand an appropriate long-term current supply capability will meeting all the
2   power fault test requirements with suitable series power resistors.
3
4   The 600 V AC, 60 A and 40 A tests and the 120 V AC tests have the special
5   requirement that the starting phase angle of the applied voltage for the 600 V AC, 60 A
6   and 40 A tests and the 120 V AC tests needs to be controlled to values of 5°, 45°,
7   90°and 135° with a tolerance of +/- 1 degree.
8

9   Table 1: AC power fault tests and their related equipment standards
          Generator                  Generator                   Equipment Standard
       AC open-circuit        AC short-circuit current                Reference
           voltage                     (rms),
            (rms)               maximum test time
    600 V                    60 A, 5 s                      GR-1089-CORE, Issue 4, clause
                             Note 3                         4.6.12
                                                            clause 4.6.15, Table 4-13, test
                                                            11
                                                            Table 4-15, test 10
    600 V                    30 A, 25 A, 20 A, 12.5 A       GR-1089-CORE, Issue 4, clause
    (Default-voltage         10 A, 7 A, 5 A, 3.75 A, 3 A,   4.6.11,
    limiting                 ,                              clause 4.6.14
    primary)                 2.6 A and 2.2 A, 900 s
    425 V                    30 A, 25 A, 20 A, 12.5 A       GR-1089-CORE, Issue 4,
    (Medium-voltage          10 A, 7 A, 5 A, 3.75 A, 3 A,   Table 4-13, test 9, test 14
    limiting                 ,                              Table 4-15, test 13
    primary) Note 1          2.6 A and 2.2 A, 900 s
    283 V                    30 A, 25 A, 20 A, 12.5 A       GR-1089-CORE, Issue 4,
    (Low-voltage limiting    10 A, 7 A, 5 A, 3.75 A, 3 A,   Table 4-13, test 9, test 14
    primary) Note 1          ,                              Table 4-15, test 13
                             2.6 A and 2.2 A, 900 s
    special value            30 A, 25 A, 20 A, 12.5 A       GR-1089-CORE, Issue 4, clause
    (Specific-voltage        10 A, 7 A, 5 A, 3.75 A, 3 A,   4.6.14,
    limiting                 ,                              Table 4-13, test 9, test 14
    primary) Note 1 and      2.6 A and 2.2 A, 900 s         Table 4-15, test 13
    Note 2
    600 V AC                 40 A, 1.5 s                    UL 60950-1, clause 6.4, clause
                             Note 3                         NAC.3.3
                                                            UL 1459, Issue 3, clause 59.18
                             7 A, 5 s                       UL 60950-1, clause 6.4, clause
                                                            NAC.3.3
                                                            UL 1459, Issue 3, clause 59.18

                                               13
                                               PN-3-0340-RV4 to be published as TIA/TSB187


                               2.2 A, 1800 s                 UL 60950-1, clause 6.4, clause
                                                             NAC.3.3
                                                             UL 1459, Issue 3, clause 59.18
     120 V AC                 25 A, 900 s                    GR-1089-CORE, Issue 4, clause
                              Note 3                         4.6.17,
                                                             Table 4-8, test 1a
                              25 A, 1800 s                   UL 60950-1, clause 6.4, clause
                              Note 3                         NAC.3.3
                                                             UL 1459, Issue 3, clause 59.18
     Note 1. Used when there is an agreed or integrated primary protector.
     Note 2. Manufacturer defined primary protector, not covered by the medium- or low-
     voltage limiting
     categories. The open-circuit voltage is equal to the highest AC voltage that will not
     operate the specific
     agreed or integrated primary protector. Limiting voltage should not be lower than 120 V
     ms to avoid
     operation during 120 V AC tests
     Note 3: Applied voltage starting phase angle controlled to 5°, 45°, 90°and 135° with a
     tolerance of ±1°.
1
2    5.4    Lightning Impulse Surges
3
4    Table 2 lists the various generator capabilities used for lightning surge impulse testing.
5    These surges simulate the variety of surge conditions possible in the environment The
6    table rows are by reference document, by test type, generator capability and then
7    byequipment standard reference. impulse duration. The reference document column
8    gives the reference document, the test clause and any table test reference. The test
9    type column has two row blocks. One is for of impulse and the other is for coordination.
10   The coordination row tests for interaction between a primary protector and a secondary
11   protector. The impulse row does not.
12   and the generator capability column has rows of decreasing impulse duration.
13
14   Table 2 has multiple9 generator test capability rows. This doesn’t mean 9 that separate
15   impulse generators are required for each row sinceas a single generator canmay
16   provide the required capability for multiple rows. For example a 2 kV, 200 A, 10/1000
17   generator can be used for the 1 kV, 100 A, 10/1000 testing. The commercial impulse
18   generators used for the ACTA-adopted ANSI/TIA-968-A (formerlypreviously FCC Part
19   68) typically provide test capabilities for 1.5 kV, 10/700 impulses, 800 V, 100 A, 10/560
20   impulses and 1.5 kV, 200 A, 10/160 impulses.



                                                 14
    PN-3-0340-RV4 to be published as TIA/TSB187

1
2




      15
                                               PN-3-0340-RV4 to be published as TIA/TSB187


1    Table 2: Lightning impulse tests and their related equipment standards
2
     Test Type       Generator Capability       Equipment Standard Reference
     Impulse         1 kV, 100 A, 10/1000 s    GR-1089-CORE, Issue 4, clause 4.6.6, Table     Formatted
                                                4-2, Test 3
                     5 kV, 500 A, 2/10 s       GR-1089-CORE, Issue 4, clause 4.6.8, Table
                                                4-4
                     1.5 kV, 100 A, 2/10 s     GR-1089-CORE, Issue 4, clause 4.6.9, Table
                     or                         4-5, Test 2,
                     1.5 kV, 100A, 1.2/50-      Table 4-6
                     8/20 s
                     1.5 kV, 10/700 s     UL 60950-1, clause 6.2.2.1 and ANSI/TIA
                                           968-A, clause 4.2.2.1
                  800 V, 100 A, 10/560 s ANSI/TIA 968-A, clause 4.2.2.1
                  1.5 kV, 200 A, 10/160 s ANSI/TIA 968-A, clause 4.2.2.2
     Coordination 2 kV, 200 A, 10/1000 s GR-1089-CORE, Issue 4, clause 4.6.7, Table
                                           4-3
                  4 kV, 500 A, 10/250 s   GR-1089-CORE, Issue 4, clause 4.7, Table 4-
                                           12
3

4    6     Classifications

 5   6.1   Microclimate Environments
 6
 7   As discussed in clause 4.1.1 of UL Subject 25641.2.1, equipment controlled, and
 8   uncontrolled ambient temperature ranges set the component controlled and
 9   uncontrolled microclimate assessment temperature ranges. Manufactures define the
10   special microclimate assessment temperature ranges. The three microclimates
11   specified in UL Subject 2564 are:
12
13                  controlled microclimate: 5°C to 70°C for Class I environment components
14                  uncontrolled microclimate: -40°C to 85°C for Class II environment
15                   components
16                  special microclimates: minimum and maximum temperatures are defined
17                   by the manufacturer for Class III environment components
18
19   6.2   Voltage Groups
20         Four Voltage Groups (VG) arehave been defined in 4.1.2 of UL Subject 2564:
21               Group I - 600 Vrms

                                                 16
                                               PN-3-0340-RV4 to be published as TIA/TSB187


 1                 Group II - 425 Vrms
 2                 Group III - 283 Vrms
 3                 Group IV - 120 Vrms
 4
 5   Voltage Groups I, II,and III and IV correspond to Categories defined in GR-1089-CORE
 6   as “High-Voltage Limiting Category”, “Medium-Voltage Limiting Category” and “Low-
 7   Voltage Limiting Category”, respectively. These categories are used for equipment that
 8   is designated to be tested as either “Agreed Primary Protectors” or “Equipment with
 9   Integrated Primary Protectors.” Group I is also the default voltage used for Power Fault
10   testing. Group IV corresponds to the GR-1089-CORE Intrabuilding Power Fault test
11   level. Note: The Group IV test level is also used for the L5 tests of UL60950-1 and
12   UL1459. However, this alone is not sufficient to qualify a device for use in UL60950-1 or
13   UL1459 since other test voltage levels are specified.
14
15   Another option n option to these four Voltage Groups is a “specific voltage limiting
16   category” as defined in Table 6. is to test to the “specific voltage limiting category”
17   defined in Table 6.
18


19   7      Key Parameters

20   7.1    DC resistance range

21          This parameter is intended to provide basic information regarding 1) consistency
22          of components from lot-to-lot and part-to-part and 2) the potential affect of the
23          protector on circuit operation due to voltage drop across the component. The
24          resistance measurement is made using a low level current to limit heating of the
25          device. We often refer to this as “cold resistance”. Non-resettable protectors,
26          such as a fuse, are often measured to determine if the DC Resistance is
27          relatively consistent. This parameter can vary a considerable amount from
28          device to device without significantly affecting the component function or
29          precision. In most cases, the second issue is far more important. Both
30          resettable and non-resettable protectors will have some cold resistance, but they
31          may have an even higher resistance at the typical circuit operating current.

32   7.2    Maximum continuous operating voltage rating

33          Protectors covered in the UL Subject 2564 are employed in telecommunications
34          DC circuits where the DC voltage and current levels areis relatively low.
35          Therefore, we do not require a DC voltage rating for these devices is not
36          required. The main purpose for these protectors is to insure isolation of the
37          communications circuit from a communication line that has been accidentally

                                                  17
                                             PN-3-0340-RV4 to be published as TIA/TSB187


1          placed in contact with an AC power line.

2
3    7.3   Maximum limited duration voltage rating

 4         This rating is based on theis an AC voltage rating with the highest fault current
 5         that can be impressed on the communications line during accidental line cross
 6         for a limited time duration. The upper limits for this voltage rating are related to
 7         the overvoltage protector type that is shunting the surge current to the ground. at
 8         a given voltage. These voltage protectors can be carbon blocks, gas tubes or
 9         solid state devices. It has beenis accepted throughout the telecommunications
10         industry that the worst case voltage will be 600 Vac. based on legacy installations
11         using carbon blocks. It has been determined that the maximum duration of this
12         overvoltage will not exceed 5 seconds, or 1.5 seconds, depending on the
13         equipment standard being employed.

14         Overvoltage limits are provided for each Annex A template description, based on
15         the related equipment standard. These range from 120 Vac to 600 Vac, as noted
16         in the Voltage Groups (VG) in section 4 of UL Subject 2564.

17   7.4   Maximum continuous hold current

18         The Annex A templates of UL Subject 2564 provide for ACCEPTABLE and
19         UNACCEPTABLE regions for device operation, but do not identify how much
20         current a specific device can carry over extended periods of time..                    Formatted


21         Maximum continuous current or “hold current” This is the lowest current point
22         level just below the on the device I-t curve. at the lowest current point on the
23         curve. Resettable protector operation in the ACCEPTABLE region is
24         permissible. Non-resettable protector operation isProtectors are expected to
25         continuously carry thisa current defined at the lowest current point on the curve
26         for 900 seconds, minimum. If no time limit were provided, non-resettable
27         protectors could open frequently and result in nuisance operations where the
28         protector would require replacement in the field. This device I-t curve must
29         comply with the appropriate template in Annex A, whose selection is dependent
30         on the application.

31         Another issue raised with cContinuous current for extended time periods in non-
32         resettable protectors at the maximum continuous hold current level can result in
33         significant temperature rises for small devices and may require special design
34         considerations.is the temperature rise. Relatively small devices can get quite
35         hot when conducting this current level for a significant time period.

36         Though rare, encountering maximum continuous current levels of this value is
37         possible. This hold current        (maximum continuous current) value is

                                                18
                                             PN-3-0340-RV4 to be published as TIA/TSB187


1          intended to provide guidance to help prevent nuisance tripping in applications.

2    7.5   Maximum limited duration fault current carrying rating

3          Different equipment standards require the protectors covered in UL Subject
4          2564 to safely interrupt a maximum fault current at the rated maximum limited
5          duration open circuit voltage. at specific levels. Examples include the ability to
6          safely open a circuit with a full fault at 60A, 600 Vac, 40A, 600 Vac or 25A, 120
7          Vac. The levels are defined for applications described in Annex A templates.

 8         As noted in the explanation of maximum limited duration voltage rating, above,
 9         these tests will be applied for a time duration not exceeding 5 seconds or 1.5
10         seconds, depending on the equipment standard.

11   7.6   Surge current impulse withstand rating

12         Equipment in the field may be exposed to lightning surges.will be subject to
13         lightning generated surges of very short duration and relatively high levels of
14         current. Protectors covered byin UL Subject 2564 will be able to safely
15         withstand these lightning induced surge currentscurrents. Non-resettable,
16         resettable and ECL protectors must also be able to withstand multiple lightning
17         surges defined in UL Subject 2564 while continuing to meet the appropriate
18         normative Annex A template requirements. their data sheet specifications. They
19         must ECL resettable protectors must remain operational limit safely and reset to
20         their original condition after withstanding such multiple hits. PTC resettable
21         protectors must not trip.

22         The surge current impulse withstand rating is a measure of the device’s ability to
23         withstand a variety of surges defined for the appropriate template as found in
24         Table 5 of UL Subject 2564.
25




                                                19
                                                PN-3-0340-RV4 to be published as TIA/TSB187


1    8     Marking
2    The information marked on all protectors covered by this outline shall be legible,
3    permanent and include the following information with the corresponding unit of
4    measurement:
5          a)    The manufacturer’s name, trademark, or both
6          b)    Unique identifier (part number, Type, etc);
7          c)    Maximum limited duration voltage rating;
8          d)    Factory ID Code (if manufactured in multiple locations).
9          e)    Templates met
10
11         Note: Minimum marking on the component shall include (a) and (b). Minimum marking
12         on the smallest package label shall include all parameters of those listed.
13
14
15
16
17
18
19
20
21
22




                                                   20
                                               PN-3-0340-RV4 to be published as TIA/TSB187


1    9      Templates
2    9.1    Template rationale

 3   Defining protection of wire in a communications system has been accomplished in the
 4   past by employing “wire simulators”. The logic was that if the “wire simulator” (typically
 5   a specific type and current rated commercially available fuse) was not opened, a given
 6   type and size wire employed in the field would not be damaged due to current overload
 7   or significant lightning surge currents. The use of these “wire simulators” was cost
 8   effective and easy to implement. The problems associated with use of these
 9   “simulators” were that they were not consistent in constant current carrying or surge
10   withstand capability from device to device or from lot to lot. Some “wire simulators” of a
11   given construction were discontinued by the manufacturer and replacement devices
12   were not exactly the same.

13   In an effort to better standardize these devices, it was decided to use the I-t curves for
14   the given “simulators” rather than use the simulators themselves. The resulting set of
15   curves is now referred to as “Templates” in Annex A. It should be noted that the limits
16   established by the templates have sufficient derating from currents that could cause
17   cable wire damage or overheating.

18   Each protector test, including voltage, current and time parameters are associated with
19   a specific test number, Groups, Templates and relevant Equipment Standards in Table
20   3 of Subject 2564.

21
22   9.2    Template application
23
24   Measurements of steady state current for durations and current limits defined by the
25   templates will provide a test mechanism for protection of the associated circuit wire at
26   23 °C. Those protectors limiting current for a maximum time, as defined by the
27   template ACCEPTABLE region, are acceptable for use with the associated type of
28   application for a given template. If the protector under test permits the current to
29   exceed the maximum limit and time for a given template, this will be considered
30   UNACCEPTABLE. This fixed line will set ACCEPTABLE/UNACCEPTABLE limits for
31   any type of non-resettable or resettable protector that is intended for use with the
32   specified equipment standards.
33




                                                 21
                                                       PN-3-0340-RV4 to be published as TIA/TSB187



                                       100

                                                        Unacceptable Region
                     Current (A rms)




                                        10




                                         1
                                                  Acceptable Region


                                       0.1
                                          0.01   0.1          1     10      100      1000

1                                                      Duration (Seconds)
2
3                 Figure 1 (Example: Subject 2564, Figure A1 – Template A)
 4
 5   Care has been taken to set these templates at levels that will assure protection of a
 6   transmission wire regardless of the associated load impedance. In many instances,
 7   circuit related impedance and line impedance will limit the current that passes through
 8   the protector. Since protector manufacturers do not know where a given protector will
 9   be installed, it was decided to set the curves for the worse case scenario.
10
11   9.3   Template temperature correction
12
13   All current protectors covered in UL 2564 will be affected by ambient temperature
14   changes. Each type of protector has its own sensitivity to temperature. Some are linear
15   and some are non-linear. Most have positive temperature coefficients. Subject 2564,
16   Table 2 and Informative Annex D, have been included to provide guidance for Template
17   curve adjustments for each type of protector technology. Most protectors will be
18   employed in temperature controlled facilities. However, temperatures in a given cabinet
19   or on a specific board may differ considerably. Ambient temperature variations can also
20   be extreme.
21

22   See Service Environment Conditions in 1.2, above, as well as Section 3 and


                                                         22
                                              PN-3-0340-RV4 to be published as TIA/TSB187


1    Environmental Classifications in Section 4 of Subject 2564 for further information.

2    10     Test Sequence Flow Chart

3            10.1 See attached chart

4    11     Equipment Standards

5                 Telcordia GR 1089, Issue 4 (Central Office Equipment)

6                 UL 60950-1, Second Edition (Customer Premises Equipment)

7                 UL 497A, Third Edition (Secondary Protectors for Communications
8                 Circuits)

9                 TIA 968-A-5

10                UL 1459, Third Edition

11

12   12     Parts
13   12.1 Part 1 of is the main portion ofUL Subject 2564 contains the general                   Formatted
14   requirements for low-Voltage Surge Withstand Telecommunications Overcurrent                 Formatted
15   Protector Components, . It provides all the testing procedures and requirements for
16   meeting this standard.
17                                                                                               Formatted
18   12.2   Parts 2 through 5

19   Parts 2 through 5 are each directly related to Part 1, and contain modifications
20   associated with each technology covered. These Parts are assigned to the following
21   technologies:
22
23                Part 2 – Fuses
24                Part 3 – Polymeric PTC Thermistors
25                Part 4 – Line Feed Resistors (LFR)
26                Part 5 – Electronic Current Limiters (ECL)
27

28   12.2.1 Fuses are tested to Parts 1 and 2. These fuses will have been tested to all of the
29          requirements of Part 1, as amended or expanded by Part 2. The only additions
30          in Part 2 include recommended standardized test boards for surface mount and
31          through-hole fuses.
32
33   12.2.2 Polymeric PTC Thermistors are tested to Parts 1 and 3.
34



                                                23
                                               PN-3-0340-RV4 to be published as TIA/TSB187


 1   A polymeric PTC is made by mixing carbon black into a suitable polymer, typically
 2   polyethylene. This mixture is extruded into a thin sheet, upon which foil electrodes are
 3   pressed. The resulting material is divided into chips, which are then packaged to form
 4   the finished device.
 5
 6   The amount of carbon black in the polymer is adjusted so that under normal operation
 7   the carbon black is relatively densely packed. In this state many conductive paths are
 8   formed between the two electrodes, and the resistance of the device is low [see Figure
 9   1]. This state is maintained at low currents.
10
11
12
13
14
                                               heats up
15
16
17
18
19
20                                           cools down
21
22
23
24    Figure 2. Morphology of a polymeric PTC device as it heats up and cools down.
25
26   As the current through the device increases, it heats up. Heating causes the device to
27   expand, breaking many of the conducting chains [again see figure 1].
28
29   As heating continues, the device reaches a temperature at which the device resistance
30   increases rapidly with further increase in temperature [see Figure 2]. The current at
31   which this rapid increase in resistance occurs is called the tripping current. For currents
32   equal to or greater than the trip current, the device is said to be tripped. In the tripped
33   state the device has a high resistance, which is maintained by a small current. When
34   this current is removed, the device cools down and reverts to its original low-resistance
35   state. The overall process is illustrated in Figure 1.
36
37   Currents lower than the trip current are called hold currents. For a given device, the
38   maximum hold current and the minimum trip current are the same. For a group of
39   devices the hold (trip) current will vary over a range, due to production spreads. So a
40   data sheet will typically specify the bottom of this range as the hold current, and the top
41   of the range as the trip current.
42
43




                                                 24
                                             PN-3-0340-RV4 to be published as TIA/TSB187


 1
 2
 3
 4
 5
 6
 7
 8
 9                                                     Switched
10
                            Resistance




11
12
13
14
15
16
17
18
19                                       Normal
20
21
22
23                                            Temperature
24
25                 Figure 3. A typical RT curve for a Polymeric PTC device
26
27   Heat energy may be supplied to the device in two forms: the thermal environment, and
28   I2R heating due to current flowing through the device. As the heat from the environment
29   increases due to increased temperature, the amount of I2R heating the device can
30   accommodate without tripping decreases. So the hold and trip currents for a device are
31   temperature dependent. This temperature dependence leads to a thermal derating for
32   the device. The thermal derating is captured in clause 3.1.2, Table 2 of Subject 2564.
33
34   Surge tests such as the one described in clause 7.5 of Subject 2564 may have enough
35   energy to trip a polymeric PTC device. If that happens the voltage of the surge is often
36   high enough to cause the device to flash over, which can affect the ability of the device
37   to perform its intended function. In this case the device selected may require additional
38   series resistance in order to pass the surge current test of clause 7.5. The device
39   manufacturer should be consulted for applications that fall into this category.
40
41   In running the test in clause 7.6 of Subject 2564, it may matter which type of
42   overvoltage protection is used in the test. A GDT (Gas Discharge Tube) with a limiting
43   voltage specified at 1000 V/μsec has a lower limiting voltage on a 10/1000 surge than a
44   thyristor with a limiting voltage specified at 1000 V/μsec; leading to the possibility of



                                                  25
                                               PN-3-0340-RV4 to be published as TIA/TSB187


 1   passing the test with a GDT, but failing the test with a thyristor. For this reason the type
 2   of overvoltage protector used needs to be specified.
 3
 4   12.2.3 Line Feed Resistors (LFR) are tested to Parts 1 and 4
 5
 6   The basic Line Feed Resistor (LFR) consists of thick-film resistors screen-printed onto a
 7   ceramic substrate. Attached “Tulip” clip headed leads provide through hole for surface
 8   mounting of the component. The thick-film resistor can be laser trimmed for accurate (1
 9   %) matching of dual resistor LFRs. Thick-film resistors have the ability to withstand high
10   voltage impulses without flashover making the LFR an excellent primary-secondary
11   protection coordination element. The range of resistance values is typically from a few
12   ohms to several hundred ohms.
13
14   LFRs can be made into complex hybrids by integrating on the substrate additional
15   resistors, multiple devices, surface mount fuses, or even a different protection
16   technology. Adding such things as overvoltage protectors gives coordinated sub-
17   systems.
18
19   Operation
20
21   AC current interruption occurs when the high temperature developed by the resistor(s)
22   causes mechanical expansion stresses that result in the ceramic breaking open. Low
23   current power induction may not break the LFR open, creating long-term surface
24   temperatures of more than 300 °C. To avoid heat damage to the PCB and adjacent
25   components, maximum surface temperature can be limited to about 250 °C by
26   incorporating a series thermal fuse (solder) link on the LFR. The link consists of a solder
27   alloy that melts when high temperatures occur for periods of 10 seconds or more.
28
29   Figure 4 shows the two current interruption mechanisms; fuse link operation and
30   ceramic fracture.




                                                 26
                                                                                                    PN-3-0340-RV4 to be published as TIA/TSB187




1
2    Figure 4.Current interruption by fuse link operation and by ceramic fracture
3
4    Figure 5 shows an LFR current interruption characteristic. Up to about ten
5    seconds there is little difference if fuse links are fitted or not. Over ten seconds,
6    the fuse links cause the LFR to interrupt at lower currents. Overall there is little
7    difference if one or two resistors are powered.
8
                                                                         Dual Resistor LFR — Current vs Operate Time
                                                                             Ceramic Only (co), Fuse link version (f)
                                                                   LFR in Single Resistor (s) and Dual Resistor (d) Modes
                                                                   20


                                                                                                                            cos_current
                                                                                                                            cod_current
                                                                   10                                                       fs_current
                                                                                                                            fd_current
                            RMS Current per Resistor Element – A




                                                                    5



                                                                    3


                                                                    2




                                                                    1




                                                                   0.5



                                                                   0.3
                                                                     0.01 0.02   0.05   0.1   0.2   0.5    1     2     5   10   20        50   100

 9                                                                                                  Operate Time – s



10                                                             Figure 5. LFR current interrupt times

                                                                                                          27
                                              PN-3-0340-RV4 to be published as TIA/TSB187

1
2    An LFR can be made to operate at lower currents (and temperatures) by integrating a
3    series connected PTC thermistor. Although PTC thermistors may be used alone, series
4    connection with an LFR reduces peak currents and thereby allows smaller cross-section
5    PTC thermistors to be used. The thermal coupling of an integrated module also ensures
6    that the LFR heating further increases the rate of PTC thermistor temperature rise
7    during AC faults causing faster low current tripping. The series LFR resistance will
8    reduce the impulse current increase of ceramic thermistors and reduce the relative
9    effect of the polymer thermistor trip resistance change.
10
11   Testing considerations
12
13   The LFR weight and high operating temperature could result in desoldering and
14   movement, causing displacement on the PCB or ultimately falling off. Both these
15   conditions can be tested for by the use of a test PCB at specific orientations as
16   shown in Figures 5-2 and 5-3 of Subject 2569.
17
18   Under high current conditions the LFR will fragment and under low-current
19   conditions the LFR will run at high temperatures. Two avoid an unrealistic test
20   evaluation, the cheesecloth hazard indicator must be spaced off from the LFR as
21   described in Subject 2569.
22
23
24
25   12.2.5 Electronic Current Limiters are tested to Parts 1 and 5.




                                                28
     PN-3-0340-RV4 to be published as TIA/TSB187


           Start




      Verify Supplier
        Datasheet
           (5.1)




    Review Applicable
     Device Section
       (Parts 2-6)




          Record
    Environment Class
           (4.0)




     Record Voltage
        Group
        (4.1.2)




    Identify Template
        (Table 1)




    Verify Part Marking
            (6.0)




           Test
           (7.0)




            A



1




         29
                                           PN-3-0340-RV4 to be published as TIA/TSB187




                                                        A




    Maximum      Resistance   Limited         Max.          Surge       Surge       Surge      Limited
    Continuous     (3.4.3)    Duration      Limited         Current     Current     Current    duration
     Current                  Current       Duration        (3.4.1)     (3.4.1)     (3.5.1)    carrying
      (3.4.2)                  (3.4.5)      Current                                            current
                                             (3.4.4)                                            (3.5.2)




      Temp.      Resistance   Temp.          Temp.           Temp.       Temp.       Temp.      Temp.
       Cycle       (3.4.3)     Cycle          Cycle          Cycle       Cycle       Cond.      Cond.
      (3.4.2)                 (3.4.5)        (3.4.4)        (3.4.1.1)   (3.4.1.2)   (3.2a or   (3.2a or
                                                                                     3.3a)      3.3a)




       Test                    Test           Test           Test         Test        Test      Test
       (7.2)                   (7.3)          (7.4)          (7.5)        (7.6)     (7.5 and    (7.3)
                                                                                      7.6)




     Criteria      Criteria   Criteria       Criteria       Criteria    Criteria    Criteria   Criteria
     (7.1.6)      (3.4.3.3)   (7.1.6)        (7.1.6)        (7.1.6)     (7.1.6)     (7.1.6)    (7.3.4)




                                         Finish




1



                                                  30

								
To top