Short circuit test Serie KP 39/53

Test:

Three twisted 20 kV single-core cables with cross-linked polyethylene insulation and cross sections of 300 mm² were laid out in a U-shape and held in trefoil arrangement by the Cable Clamps.

Test No. Is
kA
a
cm
l
m
F
N
189-79/71 64,9 4,3 1,05 18.250
189-79/72 64,3 4,3 1,31 22.350
189-79/75 80,0 4,3 0,84 22.200
189-79/76 81,3 4,3 1,05 28.650
189-79/78 110 4,3 0,44 22.000
189-79/79 111 4,3 0,44 22.400

Findings:

Cable Clamps withstood short-circuit forces of 18,250 N to 28,560 N without damage. Photographs (Picture 3, Picture 4, Picture 5, Picture 6) show the behaviour of the trefoil during and after the surge. Tests revealed that closer spacing of clamps slightly reduces heights cable jump to.
Considerable bending of cables between clamps was observed.

Photographs 7 (Picture) and 8 (Picture) how the trefoil before and after tests 189-79/78 and 189-79/79. Here, as well, there is considerable bending of cables after two 110 kA surges, although the 44 centimetres between clamps is the spacing normally used in practice. In these tests, the cables jumped to heights of only 0.2 to 0.3 m.