Iberdrola have started to install the new electrical meters on UGR. These type of meters detect the amount of load that the property is using at a given time. If this load is greater than the contracted amount then the supply will be disconnected.
If you are experiencing power cuts when you have large power items running, but the fuse board does not trip, then the cause could be the new meters.
To rectify the problem you will need to change the contracted rate by logging onto the Iberdrola website and changing the contract to a higher setting.