GB 4943.1-2011 Information technology equipment—Safety —Part 1: General requirements (Text of Document is in English) - Beijing translation compay

Contents
Foreword 1
Introduction 11
0 Principles of safety 11
0.1 General principles of safety 11
0.2 Hazards 13
0.3 Materials and components 18
1 Scope 19
1.1 Scope 19
1.2 Terms and definitions 21
1.3 General requirements 48
1.4 General conditions for tests 50
1.5 Components 58
1.6 Power interface 67
1.7 Markings and instructions 68
2 Protection from hazards 81
2.1 Protection from electric shock and energy hazards 81
2.2 SELV circuits 94
2.3 TNV circuits 97
2.4 Limited current circuits 104
2.5 Limited power sources 106
2.6 Provisions for earthing and bonding 108
2.7 Overcurrent and earth fault protection in primary circuits 120
2.8 Safety interlocks 124
2.9 Electrical insulation 128
2.10 Clearances, creepage distances and distances through insulation 134
3 Wiring, connections and supply 173
3.1 General 173
3.2 Connection to a mains supply 178
3.4 Disconnection from the mains supply 191
3.5 Interconnection of equipment 195
4 Physical requirements 197
4.1 Stability 197
4.2 Mechanical strength 198
4.3 Design and construction 204
4.4 Protection against hazardous moving parts 218
4.5 Thermal requirements 219
4.6 Openings in enclosures 224
4.7 Resistance to fire 234
5 Electrical requirements and simulated abnormal conditions 246
5.1 Touch current and protective conductor current 246
5.2 Electric strength 259
5.3 Abnormal operating and fault conditions 264
6 Connection to telecommunication networks 270
6.1 Protection of telecommunication network service persons, and users of other equipment connected to the network, from hazards in the equipment 271
6.2 Protection of equipment users from overvoltages on telecommunication networks 274
6.3 Protection of the telecommunication wiring system from overheating 277
7 Connection to cable distribution systems 279
7.1 General 279
7.2 Protection of cable distribution system service persons, and users of other equipment connected to the system, from hazardous voltages in the equipment 280
7.3 Protection of equipment users from overvoltages on the cable distribution system 280
7.4 Insulation between primary circuits and cable distribution systems 281
Annex A (Normative) Tests for resistance to heat and fire 284
Annex B (Normative) Motor tests under abnormal conditions 289
Annex C (Normative) Transformers 297
Annex D (Normative) Measuring instruments for touch current tests 302
Annex E (Normative) Temperature rise of a winding 304
Annex F (Normative) Measurement of clearances and creepage distances 305
Annex G (Normative) Alternative method for determining minimum clearances 313
Annex H (Normative) Ionizing radiation 324
Annex J (Normative) Table of electrochemical potentials 325
Annex K (Normative) Thermal controls 326
Annex L (Normative) Normal load conditions for some types of electrical business equipment 328
Annex M (Normative) Criteria for telephone ringing signals 330
Annex N (Normative) Impulse test generators 335
Annex P (Normative) Normative references 337
Annex Q (Normative) Voltage dependent resistors (VDRs) 345
Annex R (Informative) Examples of requirements for quality control programmes 346
Annex S (Informative) Procedure for impulse testing 349
Annex T (Informative) Guidance on protection against ingress of water 351
Annex U (Normative) Insulated winding wires for use without interleaved insulation 353
Annex V (Normative) AC power distribution systems 357
Annex W (Informative) Summation of touch currents 364
Annex X (Informative) Maximum heating effect in transformer tests 368
Annex Y (Normative) Ultraviolet light conditioning test 370
Annex Z (Informative) Overvoltage categories 372
Annex AA (Normative) Mandrel test 373
Annex BB (Informative) Changes in the this standard and GB 4943-2001 376
Annex CC (Informative) Comparison table between Normative references/Bibliography in IEC 60950-1:2005 and Normative references/Bibliography in this Part 387
Annex DD (Normative) Description about the safety warning marking newly increased in the Standard 398
Annex EE (Informative) Comparison table of the Chinese, Tibetan, Mongolian, Zhuang Characters and Uyghur for sample of safety-related description in the Standard 399
Bibliography 405