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deviations in ze readings

Postby neilrobber » Wed Aug 12, 2009 6:57 pm

I have recently carried out a periodic on a feeder pillar, its a tncs and the ze reading of phase 1 was 0.11 ohms higher than the other 2. Am i right in thinking this is a rec problem that they need to rectify and also is this a code 1 fault and why?
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Postby sparx » Thu Aug 13, 2009 12:14 pm

Hi, most feeder pillars are installed as part of a private network such as on caravan parks, Army camps etc which are the resposibility of the site owner.
If the readings at the main intake position are the problem then it is the REC,s problem BUT if the readings are all within their declared normal limit for the type of supply then they won't be interested. (0.35 ohms)
You must put on your test report the worst reading obtained, if that is less than TN-C-S max then no code applies since it's not considered a fault.
It is the circuit Zs's that matter for disconnection times, as long as they comply all is well IMHO.
I would agree it is not good to have a higher reading on 1 phase, do you have previous results for comparison? I would note all 3 results in comments box for future monitoring in case getting worse,
regards Sparx
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