G
Graham Hyde
I am sure this has likely been discussed many times on the forum.
Throughout my apprenticeship I heard about the fabled shared neutral on hall/landing light circuits but never actually come across one. I was told in college there is no way of testing directly for shared neutrals !?
I am now sorting out the last parts of the portfolio of the NVQ and prepping for the AM2 in due course.
I am writing up the method statement of changing a CU to a split load board with 2 RCDS, I assisted on a CU change recently and once the new one was in the RCD's were tripping. The testing prior to the change did not indicate a shared neutral.
The guy I am working with checked the downstairs and upstairs switch's and said it suggests the shared neutral. At the time i did not think to question exactly what told him this was the case, Given the walls are all going to be replastered as part of the refurb, sorting this out was no major issue. and the circuits are now independent and the RCD's no longer trip.
Unless i am mistaken the only test that might indicate shared neutrals would be IR tests of the circuits and a combination of turning switches and mcbs on and off to see if lights still work... Are there others?
Testing is one thing but the skill i guess is in interpreting the results. What anomalies out of the normal range would i expect to see if indeed there is a shared neutral between the downstairs and upstairs light circuits when carrying out any tests ?
Also what would a visual examination of the switches show? as if all wires are in at a switch it doesn't automatically follow that the same wire is terminated in the correct point at the other end..
Finally, i have been told that often if it is too much effort to split the circuits correctly, then sometimes you will come across both upstairs and downstairs light circuits (subject to how much power the lighting outlets will draw) in one mcb on just the one side of the board to avoid tripping. Which from what i can tell is against the regs? Surely the onus is on the person doing the install to put right the issue and resolve the neutrals and not bodge it..
Any help or advice would be appreciated on this as it is something i am not too familiar with and am unsure about.
Throughout my apprenticeship I heard about the fabled shared neutral on hall/landing light circuits but never actually come across one. I was told in college there is no way of testing directly for shared neutrals !?
I am now sorting out the last parts of the portfolio of the NVQ and prepping for the AM2 in due course.
I am writing up the method statement of changing a CU to a split load board with 2 RCDS, I assisted on a CU change recently and once the new one was in the RCD's were tripping. The testing prior to the change did not indicate a shared neutral.
The guy I am working with checked the downstairs and upstairs switch's and said it suggests the shared neutral. At the time i did not think to question exactly what told him this was the case, Given the walls are all going to be replastered as part of the refurb, sorting this out was no major issue. and the circuits are now independent and the RCD's no longer trip.
Unless i am mistaken the only test that might indicate shared neutrals would be IR tests of the circuits and a combination of turning switches and mcbs on and off to see if lights still work... Are there others?
Testing is one thing but the skill i guess is in interpreting the results. What anomalies out of the normal range would i expect to see if indeed there is a shared neutral between the downstairs and upstairs light circuits when carrying out any tests ?
Also what would a visual examination of the switches show? as if all wires are in at a switch it doesn't automatically follow that the same wire is terminated in the correct point at the other end..
Finally, i have been told that often if it is too much effort to split the circuits correctly, then sometimes you will come across both upstairs and downstairs light circuits (subject to how much power the lighting outlets will draw) in one mcb on just the one side of the board to avoid tripping. Which from what i can tell is against the regs? Surely the onus is on the person doing the install to put right the issue and resolve the neutrals and not bodge it..
Any help or advice would be appreciated on this as it is something i am not too familiar with and am unsure about.
