Current Carrying Capacity of Cables with Improved Characteristics in Case of Fire

acc. to HD 604 S1

HD 604 is identical to DIN VDE 0276-604.

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
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
N2XCH / N2XCWH
*)
number of
affected
cores
3 3 1 3 3
cross-section
mm²
copper conductor
rated current in A
1,5
2,5
4
6
10
16
25
35
50
70
95
120
150
185
240
300
400
500
26
34
44
56
77
102
138
170
207
263
325
380
437
507
604
697
811
940
24
32
42
53
74
98
133
162
197
250
308
359
412
475
564
649
761
866
33
43
57
72
99
131
177
217
265
336
415
485
557
646
774
901
1060
1252
27
36
47
59
81
109
146
179
218
275
336
388
438
501
580
654
733
825
25
33
43
54
75
100
136
165
201
255
314
364
416
480
565
643
737
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

recommended values acc. to HD 604 S1, table B.2

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 250 143 149 155 159 165 170 176 181

Further technical data

Conductor Resistance

acc. to EN 60228

Current Carrying Capacity PVC Insulated Low-Voltage Cables

acc. to HD 603 S1, part 3G and HD 627 S1, part 4H