Domestic Wandering PSCC value. Is my meter goosed....

[NDG Elecs]

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Hi folks,

Just a quickie.. Testing PFC earlier today, specifically PSCC... Got a reading of 3.4kA, then did a double check straight away and got 2.1....ooh I thought so tried again and again with values ranging between the two figures above. Never had such a deviation in quick succession with PFC results like this.

PEFC measured consistently four times in a row though - on a TT. Property is approx. 10 metres from sub station.

So is my meter knacked or do I need to contact DNO about their neutral?? The latter please!!

Not tried meter on another property yet.

Thoughts welcomed. Thanks.

 

[spark 68]

It can vary quite a bit, particularly at peak times, on SP installs you are supposed to take three readings and pick the highest, on TP you are already taking more than one reading so it evens out the variations a bit better.

Edit: by this tests nature a slight variation of either voltage and/or Zs, Zp-n, Zp-p has a massive effect on the PFC reading.

 

[NDG Elecs]

It can vary quite a bit, particularly at peak times, on SP installs you are supposed to take three readings and pick the highest, on TP you are already taking more than one reading so it evens out the variations a bit better.

Edit: by this tests nature a slight variation of either voltage and/or Zs, Zp-n, Zp-p has a massive effect on the PFC reading.

Thanks Spark, I was never taught to take three readings, although I usually hit the test button a few times as that's just me.

Must have been on an ad break for Loose Women I reckon and everyone was getting their cuppas!

Thanks again.

 

[spark 68]

I should have perhaps said on SP three readings of each Zdb and Zp-n (PEFC and PSCC) should be taken then the highest recorded, I am not actually sure if it is in GN3 or not, I was taught this anyway, and if I remember it was also mentioned on my 2391 course.