IG-247-EN version 02; 08/12/2020
22
Installation
General instructions
cms
.21
5.6.2. Exterior earthing network
[3]
The Earthing Installations section of the High-Voltage Electrical Installations Regulation (ITC-RAT 13) Royal Decree 337/2014, of 9th May, sets
out the requirements for this type of installations in Spain.
The installation project must include the implementation
of the earthing network (check the standard project of the
Utility Company or local regulations in force), along with
justification of sizing
[3]
.
Access of the exterior earthing network to the inside of the
cms
.21 should be carried out through one of the Ø 50 mm
blanked holes, and then through the gap envisaged in the
floor. The exterior earthing network should be connected
to the protective disconnection box of the
cms
.21 (mark 6
of Figure 5.10)
1
Ø50 mm front blanked holes
Figure 5.11.
Transit for exterior earthing cables
1
Gap in floor
Figure 5.12.
Gap in floor to pass earth cables through
The following tightening torque should be observed:
Metric
Tightening torque [Nm]
Steel 8.8
Stainless steel
M8
21
M10
38
M12
60
Table 5.4.
Recommended tightening torques