faulty meter
- Thread starter andy
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Stick some load on 
Leakage to earth is always a real possibility - And I have seen it several times, usually on a TT system with nackered RCD.
Even with a EFL through the rod and parallel paths of 10ohm (great reading for a TT) would allow a fault current of only 23amp to flow - enough to create a substantially noticeable reading difference, and also low enough to go un-noticed, especially if the DB is a good old 3036!
Rather than swapping ccts to rcd etc, if you have one, clamp the live and neutral - they should be equal - clamp them both at once, and you should see a reading of zero.
Leakage to earth is always a real possibility - And I have seen it several times, usually on a TT system with nackered RCD.
Even with a EFL through the rod and parallel paths of 10ohm (great reading for a TT) would allow a fault current of only 23amp to flow - enough to create a substantially noticeable reading difference, and also low enough to go un-noticed, especially if the DB is a good old 3036!
Rather than swapping ccts to rcd etc, if you have one, clamp the live and neutral - they should be equal - clamp them both at once, and you should see a reading of zero.
lorraine said:
im gonna wait a few hours with the extra meter. ATM both are reading the exact same amount of power. i was thinkin last night it could be an earth leak. house was re-wired a few years ago by council and TBH, its bit of a mess so faults wouldnt surprise me
also, i seem to have a TNS-TNCS system... (earth comes from neutral block to MET and another from sheath to MET) is this allowed?!
i have a clamp meter. last night when doin some tests there was 2.3A flowing. for what was on, this seemed normal
In some areas, where the lead sheather/paper insulated cables are breaking down, the TN-S earth is unreliable - they then convert the services to PME, but also keep the connection to the sheath to ensure the sheath remains well earthed. If it wasn't used - you would probably need to main equipotentially bond to it, with permission, anyway!
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The more laod you can introduce, the better.
A faulty meter, or a fault will be more likely to show up.
A faulty meter, or a fault will be more likely to show up.
Adam_151 said:
i did try it, but total load went to 62A... so i turned some off so it was 45A... cant be arsed goin thru the hassle of gettin DNO to change the fuse etc etc since i dont have any spare i could put in
so far its lookin like the meter is actually OK. its still reading the exact same units used as the other meter. clamp meter reads 0 on earth and is reading the same for live and neutral... altho if meter continues to read the same il test all the installation properly
that doesn't negate an earth leak - they may be an alternative path to earth than through whichever earth connection you're clamping.
although this does negate an earth leak.
Hi Everyone
On the subject of fuses
my meter (well the bit before it) actually had 2 service fuses, both 60A each. WHen I changed the Consumer unit i pulled both of them out just to be safe but I thought they were only supposed to be on the live (phase)?
Lorraine
On the subject of fuses
my meter (well the bit before it) actually had 2 service fuses, both 60A each. WHen I changed the Consumer unit i pulled both of them out just to be safe but I thought they were only supposed to be on the live (phase)?
Lorraine
Lorraine
Maybe you should post this question as a new thread topic as you have a better chance of a decent reply that way. It can also come across as hijacking the current thread. It is called a service head by the way.
Maybe you should post this question as a new thread topic as you have a better chance of a decent reply that way. It can also come across as hijacking the current thread. It is called a service head by the way.
It may have been a neutral link - a solid copper bar in place of the fuse.
quick update:
both meter are recording the exact same power used, so the meter seems OK ATM. next thing to do it test proply for an earth leak
and lorraine - the 2nd fuse could be either a solid link (no fuse), fused neutral (old) or possibly the fuse for a neighbours house if built semi-detached/flat. not the first time ive seen that happen
both meter are recording the exact same power used, so the meter seems OK ATM. next thing to do it test proply for an earth leak
and lorraine - the 2nd fuse could be either a solid link (no fuse), fused neutral (old) or possibly the fuse for a neighbours house if built semi-detached/flat. not the first time ive seen that happen
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