Here some pictures of the 3 phase supply in an estate agents in Ashford, where we were fitting a new submain to fed a new DB for the 3 new wall mount split A/C units which our firm fitted:
The incoming 3 phase supply, meter, DBs & switch fuses in the cellar:


The red phase was not currently in use, so it will be used to fed the submain for the A/C DB, so as not to overload the yellow & blue phase.
Old isolator wired in vir for a submain, still in use:

Vir submain:

Boiler feed feed off the vir submain:


I will post up some pics of the new submain & DB later.
The incoming 3 phase supply, meter, DBs & switch fuses in the cellar:


The red phase was not currently in use, so it will be used to fed the submain for the A/C DB, so as not to overload the yellow & blue phase.
Old isolator wired in vir for a submain, still in use:

Vir submain:

Boiler feed feed off the vir submain:


I will post up some pics of the new submain & DB later.
