Mixing Earthing Systems

[Graeme Harrold]

Reading through section 709, the get out clause is mentioned in the Marina warning sticker 1st paragraph with mention to isolation transformers being fitted on board to prevent galvanitic corrosion.

Fully agree the best solution is a TT system as you reduce the equipotential zones and thus the resulting PD's......

 

[Wiredup]

There are clauses in the regs re preventing electrolysis, dc feed back, stray currents, etc. TNS is permitted, however, if you consider these clauses and best practice............. Also, regs say prevent damage to persons, livestock and property. The electrolysis is damaging property.

 

[Spudnik]

Doesnt anybody check the regs anymore??

 

[Wiredup]

I agree. Even if the regs say that TNS is ok, ie its not potentially lethal like TNC-S, is it only ok if due consideration has been given to other requirements in the regs, ie electrolysis etc?

In other words, are the regs their to ensure the minimum standards as far as safety is concerned? ie no one should get killed if you abide by the regs.

So the regs are based purely on safety not best practice?