10.2 Table 13. a.c. current ratings of laminated bars

Table 13. a.c. current ratings of laminated bars

Number and size of bars	Total Section	Current for stated temperature rise above 20°C ambient
mm	mm²	20°C	30°C	40°C	50°C
2 - 20 x 5	200	430	540	640	720
2 - 25 x 5	250	500	640	750	855
2 - 30 x 5	300	590	750	880	1000
3 - 30 x 5	450	800	1020	1200	1360
4 - 30 x 5	600	1030	1300	1530	1740
2 - 40 x 5	400	750	950	1120	1270
3 - 40 x 5	600	1030	1300	1530	1740
4 - 40 x 5	800	1260	1600	1890	2140
2 - 50 x 5	500	880	1120	1320	1500
3 - 50 x 5	750	1200	1520	1790	2030
4 - 50 x 5	1000	1500	1900	2240	2540
2 - 60 x 5	600	1030	1300	1530	1740
3 - 60 x 5	900	1380	1750	2060	2340
4 - 60 x 5	1200	1700	2150	2540	2880
2 - 80 x 5	800	1260	1600	1890	2140
3 - 80 x 5	1200	1700	2150	2540	2880
4 - 80 x 5	1600	2080	2630	3100	3520
2 - 100 x 5	1000	1460	1850	2180	2470
3 - 100 x 5	1500	1990	2520	2970	3370
4 - 100 x 5	2000	2420	3060	3610	4090
4 - 50 x 10	2000	2330	2950	3480	3950
4 - 60 x 10	2400	2580	3260	3850	4360
4 - 80 x 10	3200	2970	3760	4440	5030
3 - 100 x 10	3000	2880	3650	4300	4880
4 - 100 x 10	4000	3240	4100	4840	5480

Notes:

All values are bars arranged on edge and spacing equal to the bar thickness. All bars in free air and painted black.

Values for 30°C rise based on test results, values for 20, 40 and 50°C rise based on 30°C rise values and assume temperature rise proportional to 1.75 power of I.

Courtesy of Ottermill Switchgear Ltd.