Current Carrying Capacity of Cables with Improved Characteristics in Case of Fire
Bayka products
The values given below are applicable to these products:
Column N2XH [copper, without concentric conductor and braid] (with CPR or nonfire):
| Power Soil | Telekom-Power |
Column N2XCH/N2XCWH [copper, with concentric conductor or braid] (with CPR or nonfire):
| soilblack EMC | soilblack VFD EMC |
General
This section applies to the capacity under both agreed but also deviating conditions, provided that three cores are loaded in three-phase operation or only one single-core cable is loaded in DC operation.
The rated currents listed in the tables are recommended values ​​under normal operating conditions.
General Conditions
| Temperatures °C (conductor) | |
|---|---|
| maximum admissible operating temperature | +90 |
| maximum admissible temperature in case of short circuit | +250 |
Concentric conductors are grounded on both ends.
Operating frequency 50 Hz.
The tabulated loading capacities ​​are based on various conditions such as
– operating mode,
– laying conditions,
– environmental conditions.
In the event of deviating operating conditions, the loading capacities ​​are to be multiplied by suitable conversion factors, which are based on the same calculation principles and operating conditions as the given values.
Current-Carrying Capacities of Cables with Improved Characteristics in Case of Fire
Laying in air(30°C)
recommended values acc. to HD 604 S1, table B.1
| N2XH [copper, without concentric conductor and braid] |
N2XCH / N2XCWH [copper, with concentric conductor or braid] |
||||
|---|---|---|---|---|---|
| number of loaded cores |
3 | 3 | 1 | 3 | 3 |
| cross-section mm² |
copper conductor rated current in A |
||||
| 1,5 | 26 | 24 | 33 | 27 | 25 |
| 2,5 | 34 | 32 | 43 | 36 | 33 |
| 4 | 44 | 42 | 57 | 47 | 43 |
| 6 | 56 | 53 | 72 | 59 | 54 |
| 10 | 77 | 74 | 99 | 81 | 75 |
| 16 | 102 | 98 | 131 | 109 | 100 |
| 25 | 138 | 133 | 177 | 146 | 136 |
| 35 | 170 | 162 | 217 | 179 | 165 |
| 50 | 207 | 197 | 265 | 218 | 201 |
| 70 | 263 | 250 | 336 | 275 | 255 |
| 95 | 325 | 308 | 415 | 336 | 314 |
| 120 | 380 | 359 | 485 | 388 | 364 |
| 150 | 437 | 412 | 557 | 438 | 416 |
| 185 | 507 | 475 | 646 | 501 | 480 |
| 240 | 604 | 564 | 774 | 580 | 565 |
| 300 | 697 | 649 | 901 | 654 | 643 |
| 400 | 811 | 761 | 1060 | 733 | 737 |
| 500 | 940 | 866 | 1252 | 825 | 807 |
*) rated current in DC plants with far off return conductor
Current Carrying Capacity of Cables with Improved Characteristics in Case of Fire
Admissible short-circuit temperatures and rated short-circuit current densities
| cables with | admissible short-circuit temperature °C |
rated short-circuit current densities in A/mm² for a rated short-circuit duration of 1s |
|||||||
| conductor temperature at the beginning of short-circuit in °C | |||||||||
| 90 | 80 | 70 | 60 | 50 | 40 | 30 | 20 | ||
| copper conductor | 250 | 143 | 149 | 154 | 159 | 165 | 170 | 176 | 181 |
Conversion factors for different numbers of loaded cores of multi-core cables in air
acc. to HD 627 S1, part 7H, table A.1
| number of loaded cores |
Laying in air |
|---|---|
| 5 | 0,75 |
| 7 | 0,65 |
| 10 | 0,55 |
| 14 | 0,50 |
| 19 | 0,45 |
| 24 | 0,40 |
| 40 | 0,35 |
| 61 | 0,30 |