- Reaction score
- 6
Hi folks. Im a RECI contractor based in Co Sligo, Ireland . I was doing erroneous testing on a domestic board which gave me readings between 90V- 190V-240V on each of all 6 Live circuits of the RCD group.
Whilst testing for erroneous circuits, I had isolated the mcb I was testing and energised the other 5 circuits. The readings are as stated above.
Previously, in addition to the erroneous testing, I also carried out Insulation Resistance tests (Meg-Ohm) of all live conductors to each other, ie 1-2, 1-3, 1-4 etc, about 11 tests as two circuits were ring-main circuits . All readings were above 500Megs.
Similar tests were performed on each of the (disconnected) neutrals, all above 500Megs. I then repeated erroneous testing but instead of looking for a voltage at the mcb, I used the 3-pin plug lead on my Fluke 1653, and did a voltage test at each socket-outlet of the circuit under test = No Voltage shown.
This was performed on all RCD circuits.
I suspect a spur N, or L & N with a load is hiding within the installation. I noticed these erroneous voltages showed up whilst testing the additional work I had carried out, and duly had to submit a Number 3 Certificate.
This scenario is wrecking my head even though I qualified as a spark in 1975.
Any suggestions are welcome.
Robert Mulgrew
Whilst testing for erroneous circuits, I had isolated the mcb I was testing and energised the other 5 circuits. The readings are as stated above.
Previously, in addition to the erroneous testing, I also carried out Insulation Resistance tests (Meg-Ohm) of all live conductors to each other, ie 1-2, 1-3, 1-4 etc, about 11 tests as two circuits were ring-main circuits . All readings were above 500Megs.
Similar tests were performed on each of the (disconnected) neutrals, all above 500Megs. I then repeated erroneous testing but instead of looking for a voltage at the mcb, I used the 3-pin plug lead on my Fluke 1653, and did a voltage test at each socket-outlet of the circuit under test = No Voltage shown.
This was performed on all RCD circuits.
I suspect a spur N, or L & N with a load is hiding within the installation. I noticed these erroneous voltages showed up whilst testing the additional work I had carried out, and duly had to submit a Number 3 Certificate.
This scenario is wrecking my head even though I qualified as a spark in 1975.
Any suggestions are welcome.
Robert Mulgrew
- TL;DR
- I need some help with erroneous test results: false voltages showing up