TAVRIDA ELECTRIC VCB Series, User Manual, Page: 72 / 142

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a) cover the bar by shrinkable
tube in case it is required b) put insulator CBdet_RubberIns_3 on the busbar
c)
screw the bolt M12 with torque 50±2 H*m and cover the ISM terminal tightly
by put insulator CBdet_RubberIns_3
Figure 130
Installation of CBkit_Ins_4(2) in case of busbars 80x10 mm usage
Protective earthing
For personnel protection the metal housing of the ISM must be connected according to the applicable
regulations, such as IEC 62271-1, IEC 62271-100, IEC 62271-200 via the marked earth screw of the ISM to
the earthing arrangement of the particular panel. The earthing connection can be carried out with a cable or a
fat copper bar. The area around the earth screw shall be cleaned before providing the earth connection. After
the occurrence of a short circuit, the proper condition of the protective earthing must be checked.
Table 8 - Reference values for cross sections of earth connections (copper)
Fault current (1 s) Maximum temperature Cross section of earth connection
16 kA
300 °C
55-
95 mm²
20 kA
300 °C
70-
120 mm²
25 kA
300 °C
95-
140 mm²
31.5 kA
300 °C
120-
190 mm²