Mining transformer connection

[Power0020]

Working on a transformer grounding 11/.38 kV for a mining site and wonder if the LV fault level need to be controlled to achieve compliance with low fault current for trail cables and connections inside the mining area. The addition of NER seems a simple answer but give the mining loads are unbalanced a considerable neutral point shift is expected with the unbalance current feeding back to the transformer.

Any clues?

 

[Kiribanda]

Which mining code do you have to follow?
Is it open mining or underground mining?

 

[Power0020]

Australian code. I guess this is an open mining

 

[Hoxton123]

In the UK there is specific separate legislation on safety and equipment standards in Mines and Quarries. A quick search showed that each Australian State seems to have its own devolved legislation.

Here in UK there is specific legislation because of the past poor safety statistics in these areas of work due to lots of moving plant with electrical and other facilities being regularly re-sited as the excavation face moves.

I would recommend seeking out a local engineer or consultant who operates in this area. There might be a trade association who could help.