The general wisdom when dry packing, seems to be to have a 3-4" gap between the top of the old concrete and top of the old wall, is there a compelling reason you cant go thinner - say 2 inches?
If you trench under the wall on both sides, is it possible to ram the cement in from both sides and...
I am using a residual earth fault trip which fits onto the incomer of a 3P&N 400A MCCB; it uses a core balance ct around the 3 phases, I'm not given ct values because it comes as a package; I just have to choose the earth fault trip setting eg 0.03A-5A & trip time (0.01s-1s). The 'load' is 230kW...
