TAVRIDA ELECTRIC VCB Series, User Manual

Page: 42 / 142

42
To provide 95 kV BIL between ISM15_HD_1 main terminals and external frame, it is required to use the
additional spacers. Spacers are included in the CBMount_ISM15_1 kit.
Figure 68
ISM15_HD_1 mounting with help of spacers from CBmount_ISM15_1
Main terminal connections of ISM15_LD_1, ISM15_LD_3,
ISM15_LD_6 , ISM15_LD_8 , ISM25_LD_1, ISM25_LD_2, ISM25_LD_3
Primary terminals connection
Busbars can be connected to terminals of ISM LD series by means of M10 screws. M10 bolts and nuts fixing
busbars to ISM LD series
terminals should be tightened with a torque of 30±3 Nm. To connect busbars to
lower terminal of ISM15_LD_1(90) M8 bolt should be used with a torque of 10±1 Nm.
To prevent static load to the ISM poles it is not allowed to fasten busbars to the ISM terminal if there is a gap
of more than one millimeter between the busbar and the ISM terminal just before this fastening. Bars shall be
accurately prepared to avoid bending and (or) twisting forces to terminals when these bars are fastened.
Electrodynamic forces clearances
To avoid unacceptable high electrodynamic impact on the ISM, additional support insulators are required if the
unsupported busbars are longer than specified in the Table 2.
Table 2 - Additional support insulators installation minimum distances
ISM Short-circuit current
16 kA 20 kA
L1, mm
ISM15_LD series 980 700
ISM25_LD series 980 NA