MV and LV Cables in Substation

[Adriaan.S]

Good day all,

I have a contractor who is busy with a new installation of MV cables in a substation (11kV).
From experience I know that MV and LV cables are not supposed to be mixed and normally run separate from each other.
However I cannot seem to find the standards which supports this, can any body maybe point me in the right direction as to where I can find the appropriate standards for substation installations?

[GCE]

Hi

I know of these 2 regulations that guide you towards the separation of voltages - Not sure if that is what you are looking for

From Sans 10142-1
6.1.7 If conductors that operate at different voltages run in the same wireway,
the insulation of each conductor shall be able to withstand the highest
conductor voltage in the wireway. Alternatively, the conductors shall be
separated by a continuous barrier of insulating material or earthed metal.


From Sans 10142-2
5.4 Buildings and enclosures
5.4.1 Buildings shall comply with national building codes (SANS 10400-T) and fire regulations.
Amdt 1; amdt 2
5.4.2 Substation buildings shall comply with the requirements of the Electrical Machinery
Regulations (see foreword). Amdt 1
5.4.3 No exposed liquid, gas or effluent pipes with operational or service openings shall be
installed inside substation buildings.
5.4.4 A barrier shall separate the MV and LV equipment that are installed in the same building.
The MV bushing connections shall be sealed and insulated.
5.4.5 Notwithstanding the ventilation provided, rooms that contain open type lead batteries shall be
considered as locations with corrosive environments. Walls, ceilings and floors shall comply with the
requirements for protection against corrosion and gaseous products. Means shall be provided to
prevent corrosive substances from entering any drainage systems (see also the requirements for
hazardous locations in SANS 10108).