Principle

Inter building links present two special features that can introduce risks for the installation:

  • the poor equipotentiality between installation grounds,

  • the large areas of loops between the data cables and the grounds.

NOTE: Before installing and connecting a data cable between two buildings, you must check that the two ground connections (one at each building) are interconnected.

All the exposed metal parts accessible at the same time must be connected to the same ground connector (or at least to a set of interconnected ground connections). This requirement is fundamental to ensure people's safety.

The second risk associated to inter building connections is the area of loop included between the data cables and the connections.

This loop is particularly critical when there is an indirect blasting of the site. The overvoltage caused in these loops by an indirect blasting is approximately of 100 volts per m.

NOTE: In order to reduce this risk, all cable runs between two buildings must be doubled up with a large section equipotential line (»35 mm 2 ).