1、CEPT T/L*02-10*E 87 m 232b4l14 0005947 9 m 1 TlLO;-ii; (old reference: T/TR 02-1 O E) Recommendation T/L 02-10 (Copenhagen 1987) POWER SUPPLIES FOR TELECOMMUMCATIONS EQUIPMENT INSTALLED IN CUSTOMERS PREMISES Recommendation proposed by Working Group T/WG 12 “Transmission and multiplexing” (TM) Text o
2、f Recommendation adopted by the “Telecommmications” Commission: “The European Conference of Post and Telecommunications Administrations, considering - that telecommunications equipment may be installed in customers premises, - that the power supply for telecommunications equipment from various origi
3、ns requires standardisation, - that existing CCITT and CCIR Recommendations in such matters do not ensure the required standardisation, - that the CCITT and CCIR do not envisage standardising the power supply interface for telecommunications equipment installed in customers premises, - that the Admi
4、nistrations are amendable to the harmonisation of telecommunications equipment, which will lead to a lowering of development and manufacturing costs for the industry which is supplying equipment to several countries, a recommends that the members of the CEPT should apply the specifications contained
5、 in this Recommendation.” Edition of December 15, 1987 7 CEPT T/L*02-3O*E ? I 2326434 0005948 O m T/L 02-10 E Page 2 1. 2. 3. 3.1. 3.2. 4. 4.1. 4.2. 4.3. 4.3.1, 4,3.2. 5. 5,l. 5.1.1. 5.1.2. 5.1.3. 5.2. 5.3. 5.3.1. 5.3.2. 6. 7. Contents AREA OF APPLICATION . . . . . . . . . . . . . . . . . . . . . .
6、. . . . . . . . . 2 OBJECTIVES . . , , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , , . . 2 POWER SUPPLY INTERFACES . . . . , , . . . . . . . , . . . . . . . , . . . . . . 2 Power supply at interface I,. . , . . . . . . , . . . . . . , . . . . . . . . , , . . . . . 2 Power supply at i
7、nterface I,. . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 SAFETY REQUIREMENTS. . , . . . . , . . . . . . . , , . . . . . . . . . . . . . . 3 General 3 Safety requirements for the power supply installations and interfaces . . . . . . . , . . . . . . 3 Safety requirements of equipme
8、nt , . . . . . . . . . . . . . . . . . . . . . . . . , . . . 3 Telecoms equipment . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . , , 3 Other. equipment connected to Telecoms equipment or Telecoms network . . . . . . . . . . . . 3 PERFORMANCE CHARACTERISTICS . . . . . . . . . . . .
9、 . . . . . . , . . . . . . 3 Voltages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Nominal values andfiequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Tolerance of voltages andflequency in normal service . . . . . . . . . . , . . . . . . .
10、 . . 4 Impulse withstand voltages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Surge current. , , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . , . . . 4 Reaction of equipment to the power supply source . . . . . . . . . . . . . . . . . . . . . . 5 Harmonics re-i
11、njected into the ac supply . . . . . , . . . . . . . , . . . . . . . , . . . . 5 Noise re-injected on ac supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 EARTHING AND EQUIPOTENTIAL BOUNDING . . . . . . . . . . . . . . . . . . . . 5 LISTOFQUOTEDCEPTRECONDATIONSANDIECSTANDARDS . .
12、 . . . . . . 5 1. AREA OF APPLICATION This Recommendation applies to all telecommunications equipment installed in customers premises : - directly connected to the Administrations network, - having a primary or secondary power supply interface as shown in Figure 1 (T/L 02-10), - and is operated by t
13、he customer. Equipment should be developed in such a way that the power supply specifications are observed at the interfaces. These interfaces should be at a physical point at the power input to the equipment. 2. OBJECTIVES - To facilitate the harmonisation of telecommunication equipments. - To faci
14、litate the installation, operation and maintenance in customers premises, of equipment and - To define the power supply interface between the telecommunications equipment and the customers - To define safety requirements for the protection of persons either inside or outside customers premises. tele
15、communications systems from different origins. premises. 3. POWER SUPPLY INTERFACES The power supply interfaces are as shown in Figure 1 (T/L 02-10). Power supply at interface I, Where equipment is connected to the public mains/local ac generator supply via interface I, the primary power supply spec
16、ification shall be as described in sections 4 and 5. Power supply at interface I, Where equipment is connected to a secondary voltage via interface I, the secondary voltage supply specification should be in accordance with Recommendation T/L 02-02. 3.1. 3.2. Edition of December 15, 1987 CEPT T/L*OZ-
17、LO*E 87 I 2326434 0005949 2 m TIL 02-10 E Page 3 4. 4.1. 4.2. 4.3. 4.3.1. 4.3.2. 5. 5.1. 5.1.1. SAFETY REQUIREMENTS General The principle adopted in this Recommendation is that safety of persons or equipment should be assured with regard to the hazards that may come from: i) the power supply install
18、ation and interfaces, ii) the Telecoms equipment, iii) the Telecoms network, iv) other equipment connected to Telecoms equipment or the network. In each case safety specifications are given in accordance with IEC standards having a pilot function and/or the appropriate group and product standards ac
19、cording to IEC Guide 104. If no IEC standards are published for a particular aspect, appropriate Recommendations are specified from similar or other applicable IEC standards. Safety requirements for the power supply installations and interfaces Safety requirements for ac supply installations are giv
20、en in IEC Publication 364, which is the standard with pilot function for protection against electric shock and also the product standard concerning electrical installations of buildings. Where ac is used, whether at interface Il or 12, the installation must comply with IEC Publication 364. When dc i
21、s the power supply at interface I2 within the voltage ranges given in TIL 02-02 it must come from a safety source according to IEC Publication 364-4-41. Where protective earthing of the equipment is prescribed in the relevant equipment safety standards as a means of implementing the required touch-s
22、afe conditions, the protective earthing should not rely on the telecommunication network to which the equipment is connected. In situations where protective earthing does not exist, class I equipment should not be connected to telecommunications networks. Safety requirements of equipment Telecoms eq
23、uipment Telecommunications equipment should be in accordance with IEC Publication 950 which is the product standard for safety of information technology equipment including electrically operated business equip- ment. Circuitry which is to be connected to the telecommunications network should be touc
24、h-safe circuitry. Note. Touch-safe circuitry means: Circuitry whose voltages do not exceed the nominal operating levels provided by the telecommunications network and which is protected from excessive voltages coming from the mains by a “safety-source” according to IEC Publication 364-4-41. Other eq
25、uipment connected to Telecoms equipment or Telecoms network Equipment, which is not primarily designed for Telecoms purpose, e.g. personal computer or television set, may not have a power supply safety-source and therefore the circuits of these equipments are not touch-safe. If such equipment is use
26、d for Telecoms purpose and connected to the Telecoms network or Telecoms equipment, precautions must be provided to ensure that touchable circuits, e.g. the subscriber line, remain touchable according to the requirements for Extra Low Voltage in IEC Publications 364-4-41. PERFORMANCE CHARACTERISTICS
27、 Voltages Nominal values and frequency The specified nominal values are: 2201380 V ac, 50 Hz, 2301400 V ac, 50 Hz, 240/415 V ac, 50 Hz. Edition of December 15, 1987 - I I- CEQT T/L*02-10* 17 2326414 0005950 9 TIL 02-10 E Page 4 Notes. 1. The actual voltage or frequency at interface I, during normal
28、service may be any value between those specified in Section 5.1.2, 2, 220 V ac is the nominal voltage present in most CEPT member countries. 3, 240 V ac is the nominal voltage present in some CEPT member countries. 4. 230 V ac is the nominal voltage specified in IEC Publication 38 for the future and
29、 is expected to supersede other voltages in the long term. For 230 V ac nominal: For 240 V ac nominal: 5.1 $2. Tolerances of voltages and fiequency in normal service Telecommunications equipment should meet its specifications when operating from a supply within the following tolerances: For 220 V ac
30、 nominal: 198-242 V ac 49 . 51 Hz or 48 . 52 Hz (Note I) 207-253 V ac 49 . 51 Hz or 48 . 52 Hz (Note I) 216-254 V ac 49 . 51 Hz or 48 . 52 Hz (Note I) The equipment should also meet its specifications when transient voltage variations according to Figure 4 (T/L 02-10) occur at interface I,. The cond
31、itions specified in Figure 2 (T/L 02-10) and 4 (T/L 02-10) should not lead to the disconnection of equipment by tripping circuit breakers or blowing fuses. It is not specified whether equipment should operate over more than one voltage or frequency range. Notes. 1. Where the supply voltage is obtain
32、ed from a local ac generator the frequency tolerance should be f 2 Hz under settled conditions. However, transient frequency variations can exceed this tolerance. One CEPT member country has a tolerance of f 2.5 Hz under settled conditions. 2. Where closer voltage or frequency tolerances are require
33、d, a stabilised ac supply may be specified in accordance with IEC Publication 686. Where the voltage supply at interface I, is taken from a local ac generator or other local power source the higher source impedance of the supply may result in wider tolerance of voltage and frequency than given above
34、. 5.1.3. Impulse withstand voltages Telecommunications equipment should not suffer damage when overvoltage conditions on the primary voltage supply are controlled according to IEC Publication 664. 5.2. Surge current The ratio for instantaneous surge current I, to maximum RMS current I, at interface
35、Il under any random sequence of switching operations should not exceed the limits shown in Figure 2 (T/L 02-10). The circuit for measuring the surge current drawn by the equipment should be as shown in Figure 3 (T/L 02-10) (see Note). The measurement should be with the equipment powered at the nomin
36、al voltage and rated load conditions. The purpose of these requirements is to avoid spurious rupture of fuses or tripping of circuit breakers due to excessive surge current and to avoid excessive voltage depressions caused by high surge currents and power supply impedances. Note, When the source imp
37、edance is not well defined, an impedance having resistance and inductance equal to the reference impedance may be connected between the supply and the equipment terminals. Edition of December 15, 1987 5.3. 5.3.1. 5.3.2. 6. 7. T/L 02-10 E Page 5 Reaction of equipment to the power supply source Harmon
38、ics re-injected into the CIC supply The harmonics re-injected into the ac supply shall not exceed the values given in IEC Publication 555 Part 2. The measuring method should be in accordance with IEC Publication 555 Part 2. Noise re-injected on ac supply Levels of voltages, frequency and measurement
39、 methods are under study within the CEPT. EARTHING AND EQUIPOTENTIAL BOUNDING Recommendations on this subject are under study within the CEPT. LIST OF QUOTED CXPT RECOMMENDATIONS AND IEC STANDARDS T/L 02-02/1: IEC 38: IEC Guide 105: IEC 364: IEC 364-4-41 : IEC 479: IEC 555: IEC 664: IEC 686: IEC 950
40、: The rack/telecommunications centre power supply interface. IEC standard voltages. Principles concerning the safety of equipment electrically connected to a telecommu- nications network. Electrical installation of buildings. Electrical installation of buildings. Part 4: Protection for safety. Chapt
41、er 41 : Protection against electric shock. Effects of current passing through the human body (under revision). Disturbances in supply systems caused by household appliances and similar electrical equipment. Insulation Co-ordination within low-voltage systems including clearances and creepage distanc
42、es for equipment. Stabilised power supplies, ac output. Standard for safety of information technology equipment including electrically operated business equipment. Edition of December 15, 1987 I ,CEPT T/L*02-10*E 7 $B 2326414 0005952 2 T/L 02-10 E Page 6 I 11 I I I I I I I I I I -I- l I I I I POWER
43、I SOURCE -I_ I 12 I I I I I I POWER SUPPLY I- TELECOMS EQUIPMENT -I I,: Primary ac supply. 12: Note. The power supply may be integral with the Telecoms equipment, or separate. Secondary ac or dc supply (Recommendation T/L 02-02 refers). Figure 1 (T/L 02-10). Definition of power interfaces in custome
44、rs equipment. Edition of December 15, 1987 90 65 35 22 19 6 1.5 O CEQT T/L*OZ-lO*E 87 6 232bVL4 0005953 4 TIL 02-10 E Page 7 Figure 2 (T/L 02-10). Limits for ratio of instantaneous surge current to maximum RMS current at interface I,. Edition of December 15, 1987 T/L 02-10 E Page 8 I- I I I I I I L-
45、 Interface I 1 1 L1 I I OI I I I I “si I- I I I I I AC SOURCE Reference impedance of the source RA=0.24 L2 jXA=jwLA=j 0.15 i2 at 50 Hz R,=0.16 jX,=jwL,=j 0.10 Cl at 50 Hz Il EQUIPMENT UNDER TEST OR Figure 3 (T/L 02-10). Surge current test circuit for ac power supplies. Edition of December 15, 1987 CEPT T/L*02-LO*E ? E 2326434 0005955 W I - _ m -2 -Q -00 -t- -w -.io -* TIL 02-10 E Page 9 D 2- m- oo- e- w- io- *- a a a Edition of December 15, 1987 7 I O
