On Tuesday, September 23, 2014 11:45:03 AM UTC+1, News wrote:
Even more progress. Have found the monitor which E.on sent me um, eons
ago. One clamp to go around the main supply cable. Will that be the
thick red cable to the left of the meter, in the bottom picture?

That's probably your neighbour's supply.

Use one of the two cables going from the bottom of the black main fuse into your meter.

Owain