Fagor DDS Series Hardware Manual page 234

   Power line connection
6.7 Distribution diagrams
6.
238
DDS
HARDWARE
Ref.1912
· 234 ·
The distribution diagram being used must be taken into consideration in
order to determine the characteristics of the protection means against
electrical shocks, in case of failure (indirect contacts) and against over-
current, as well as the specifications of the devices in charge of such
functions. The distribution diagrams are established according to the ground
connections of the distribution network or of mains, on one hand, and the of
the grounds of the receiving installation on the other.
Depending on the electric energy distribution network, there are three types
of diagrams: TN, TT and IT.
Depending on the type of distribution diagram, the cabling in the electrical
cabinet will vary considerably.
IMPORTANT NOTE. Note that the diagrams provided here do not show
the main contactor - KM1 that must be connected between the
transformer or auto-transformer and the DDS system.