IEC\/PAS 61156-1-4:2010(E) is covering exclusively four-pair data grade cables and is intended to provide a test method for the determination of the maximum attained conductor temperatures which occur due to the deployment of the IEEE protocol for PoE \/PoEP. It gives as well the required background information about the thermodynamic behaviour of such bundled cables, if they are located in areas with restricted heat dissipation, a reality which occurs in every installation situation. However, only the basic principles are given, as the rigorous application and solution of these problems fall into the relevant cabling standards.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 4<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 6<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | 1 Scope <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 2 Normative references 3 Terms, definitions, symbols, units and abbreviated terms 3.1 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 3.2 Symbols, units and abbreviated terms <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 4 The testing of bundled cables 4.1 General comments 4.2 The bundling of cables <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | Figures Figure 1 \u2013 Lay-plate arrangement for stringing up and fixing the cables to maintain the densest hexagonal packing structure, here shown for a 61-cable bundle Figure 2 \u2013 Arrangement of cardboard\u2013mask\u2013plates over the ends of the cable bundle to apply the insulating foam over the ends of the bundle <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 4.3 The suspension of the cable bundle <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | Figure 3 \u2013 Schematic of the suspension of the cable bundle <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 4.4 Assessment of the concatenated loop resistance of all pairs <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 5 The temperature as a function of the current load in conductors of bundled cables in hexagonal densest packing structure 5.1 The test description Figure 4 \u2013 Cross-section of a cable bundle used for the test, here a bundle of 61 cables <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 5.2 The temperature measurement <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | Figure 5 \u2013 Connections on both ends of the center cable to obtain two nearly identical \u201cpair\u201d resistances, which can then be measured using the voltage across these pairs Figure 6 \u2013 View of part of the cable bundle around the measurement cables indicating the \u201ctemperature\u201d measurement leads and those for the concatenation between the cable layers in the bundle (here for n = 0 \u2026 4) <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 5.3 The heat generation and the resulting increase of the resistance <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | Figure 7 \u2013 Schematic for connecting the cables in the different layers for alternatively 2- and 4-pair heating <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 5.4 The specific resistivity referencing the IACS <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 6 Assessing already deployed cable systems 6.1 Background 6.2 The installed base <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 6.3 A simplified assessment of the installed base 7 The higher performing data grade cables 7.1 Conductor and cable diameters <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 8 The heat dissipation on heated and bundled cables 8.1 Radiation 8.2 Conduction 8.3 Convection <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 9 The heat dissipation in a heated conductor, pair or cable which has to be taken into account 9.1 The heat dissipation of individual components Figure 8 \u2013 Heat dissipation of a freely suspended conductor <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | Figure 9 \u2013 Heat dissipation of a single insulated conductor <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | Figure 10 \u2013 Dissipation of an unscreened twisted pair exposed to current heating <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | Figure 11 \u2013 Dissipation of a screened twisted pair exposed to current heating <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | Figure 12 \u2013 Heat dissipation in an unscreened cable <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | Figure 13 \u2013 Heat dissipation of an overall screened cable Figure 14 \u2013 Heat dissipation in an individually screened pair cable with overall braid or drain-wire with an overall metal \/ polymeric composite tape <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | 9.2 The heat dissipation of real cables <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | Figure 15 \u2013 A data grade cable of arbitrary design <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | 10 Thermodynamic considerations for a combined experimental and mathematical solution of the heating problem 10.1 Objective 10.2 The cable bundle considered as a layered structure <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | Figure 16 \u2013 Bundled cables indicating the air spaces between the cables Figure 17 \u2013 The thermodynamic equivalent layered structure of the cables and air gaps <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | 10.3 The heat transfer through the layered structure <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | 10.4 The heat transfer through the bundle in layered structure with internal heat generation <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Multicore and symmetrical pair\/quad cables for digital communications – Symmetrical pair\/quad cables with transmission characteristics up to 1000 MHz. Conductor heating of bundled data grade cables for limited power transmission based on IEEE 802.3<\/b><\/p>\n |