David Hansen wrote in message . ..
On 16 Sep 2003 17:14:41 -0700 someone who may be
(robsignals) wrote this:-
It comes down to NG's and
EDF's seperate Wimbledon sub-stations being operated independently
when really they should be treated as one unit but I don't think
that's a recent problem.
I would be interested in a schematic of the arrangement there. I
wonder if one will ever be provided?
There's a basic one in the report: NG have 4 seperate feeds to EDF who
split their Busbar into 2 halves. At the time one of the feeds to the
half supplying LU was out for maintenance and the other was taken out
by the phantom overload trip, the 2 remaining feeds were capable of
carrying the full load. As NG couldn't find a valid reason for the
trip although they re-closed the breakers in a few mins, after
isolating the line and EDF feed, they didn't offer supply until 18
mins after loss and EDF took 10 mins to accept. EDF continued to
reconfigure their system and weren't able to resupply all load until,
I think, 44 mins though the report isn't very specific as NG had all
supplies restored at 36 mins and aren't responsible for EDF's antics.
Once LU had decided to evacuate trains restoring their supply became
academic.