We have two electric shares in our flat. When one of them is used, a very strong smell (almost fishy) comes from the area where the mains comes into the flat. .

when you say shares i take it you mean showers, if this is the case then i would recomend you stop using that shower, because that smell is plastic melting inside the shower unit! i would say that its because: the cale to the shower is not big enough to take the ampage the shower requires, and it is melting the cable connection. is your shower curcuit on an RCD? IF NOT THEN I STRONGLY SUGGEST YOU DONT USE IT, AND POST YOUR JOB ON HERE! lee russ electech

Sometimes, the main incomer cable is sub-rated and the consumption on the flat increased in time, especially after a refurbishment. Needs a assessment done on the total consumption of the flat versus the main incomer rating (electrical supply supplier, on the meter amps) and compared with the total load capacity of the main incomer cable. As example the regs requires 25mm tails or equivalent sized armor cable for a 100A rated main incomer supply. If the tails or the armor cable is less than and the consumption peaks around 90% then the cable will overheat giving up smell. And thats a happy ending because in other situations could catch fire. Seen that on a previous development where the flat has been refurbished and the developer didnt took notice that the main incomer cable was smaller than it should. He swap the main cartridge fuse with a 100A rated one. The whole thing was fine on summer time but as soon as winter came he switched on everything and burn the main incomer cable. He wasnt a very happy person on mid December.

Sounds like there is a loose connection in the mains unit and it is over heating, I would suggest you call out an electrician as soon as possible.

Sounds like dry connection to me or loose conection also shower rating may be to high for size of cable