IG-247-EN version 02; 08/12/2020
21
General instructions
cms
.21
Installation
5.6. Earthing circuit connection
cms
.21 is fitted with an internal protective earthing circuit
for easy connection of the different elements to the external
earthing network.
5.6.1. Protective earthing network
cms
.21 has a protective earthing disconnection box inside.
Save for specific indication by the customer, the earthing
network comprises bare copper cable of section 50 mm
2
.
The earths of the medium voltage switchgear and the
steel fixing of the concrete enclosure come together in this
protective earthing switch box.
The steel fixing of the roof and, when requested, the metal
flue, also connect to the steel fixing of the enclosure.
Save for specific indication by the customer, the metal doors
and rear flap do not connect to the protective earthing
network
1
Earth connection of the cover with the concrete enclosure, bare
copper 50 mm
2
2
If specified, branching to metal flue, bare copper 50 mm
2
3
General earth line, 50 mm
2
bare copper.
4
Branching to the earthing bar of the medium voltage
switchgear, bare copper 50 mm
2
5
If specified, branching to metal flue, bare copper 50 mm
2
6
Protective earthing switch box
Figure 5.10.
Earth interconnection box