EARTHING

[PC Bester]

I have a 3phase system where cable with only 3 cores were installed, without any earth conductor. What legally earth can be created? Earth mat? Or can I convert cable to single phase and install a converter from single phase to 3phase?

 

[tom baker]

is your area under the NEC? I am not familiar with what you are asking, but there may be a few here who can help.

 

[zbang]

You're in South Africa?

The Earth conductor's main purpose is conducting fault currents back to the breaker so it will trip, that's the reason for the neutral/ground(earth) bond; any connections to actual dirt only help with lightning protection and voltage stabilization. What do the local codes say?

 

[jim dungar]

I have a 3phase system where cable with only 3 cores were installed, without any earth conductor. What legally earth can be created? Earth mat? Or can I convert cable to single phase and install a converter from single phase to 3phase?

Do you understand US terminology for ground? The NEC is very confusing when trying to be compared to non-US systems.

Is your system being installed on a US style supply prone that uses European terms like Earth and TTN?

 

[LarryFine]

I have a 3phase system where cable with only 3 cores were installed, without any earth conductor. What legally earth can be created? Earth mat? Or can I convert cable to single phase and install a converter from single phase to 3phase?

If I may:

"A 3ph system supplying a load via a 3-wire cable with no EGC. Can I use earth alone for grounding?

"Can I use 1ph and use the third wire as the EGC and provide the load with a 1ph-to-3ph converter?"

 

[Julius Right]

If we look at SANS 10142-1- the South Africa national electric code -we see it is close to British Standard BS 7671-in my opinion-and then it is close to IEC 60364-1. In the last standard, chapter 312.2 Types of system earthing, 312.2.3 IT system. The IT power system has all live parts isolated from earth or one point connected to earth through an impedance, the exposed-conductive-parts of the electrical installation being earthed independently or collectively or to the earthing of the system. However, one has to follow the further details in IEC 60364-4-41.