Hi All,
Cannot remember exactly what size the thing is right now, i will have a look tomorrow. I have managed to do away with half the redundant circuits, so i suppose an eight way one would be ok.
One thing i could use though, is a 63A SP whatever the equivalent to a "B" curve is in a BS3871 MCB to go in it...Will need to be a type 1 i think...???
It is to connect up a toilet block, that at the moment is fed in 2.5 but now they want an electric shower.. [as well as the handwash heater, the wall heater, the wall mounted convector heater, and the washing machine..]
Yep, before you ask, the original wiring, complete with connector blocks and sticky tape has melted!!! [well, at least the connector block has..]
The run length is about 40 metres to the DB, and it in turn is on the end of about 50 metres i suppose, of 70mm, so Zs is going to be the problem. I COULD fit an RCD to acheive disconnection times for the cable from the DB to the toilet block CU, but it would be much easier it i could get a "B" curve breaker, instead of the "C" curve, or type 3 ones [whatever, cannot remember right now] that are there at present.
Have not done the calcs properly yet, but fault current at that point [the DB] is about 6Ka.. [L-L] with a Zs of 0.24 Even with a "B" curve, there will not be much room to move..... Might have to do the RCD thing...
john..
