In article , News writes
Something doesn't look quite right in that bottom picture.
To the left of the meter there is what looks like the supplier's fuse with the main (thick red) feed coming in at the top but there appears to be another thinner red connection wire daisy chaining into the unprotected side of the fuse.
If it really is connected at that point then it doesn't look right at all. As it is on the supplier's side then it wont be an answer to your metering problem but running an unprotected spur in undersize cable looks decidedly dodgy.
Maybe see if you can find where that goes, the shop perhaps?
Anyway, back to the metering, if you apply the clamp to the big red wire and the spur is as it looks then you will be measuring any current going off in that limb too. You would be better applying the clamp to wire 1 going into the meter. Actually, there's more slack on the neutral (wire
2) so that would be easier and the sensor doesn't care which side it's on.