Question 1 - AFDDs
We are looking at installing combined AFDDs/RCBOs to existing switchrooms located in some High rise flats starting with the landlords supplies then moving on to the consumer units located within the flats themselves. The issue with the landlords supplies is that there is no manufacturer that appears to make the AFDD bigger than a 40Amp range and also they are unavailable in 3 phase. Therefore if we carry this work out then a number of circuits eg where you have a 63Amp 3 phase lift supply then this will need to be mounted in another seperate enclosure with cct fed via an MCB thus we are only doing half a job - any ideas ? EATON suggest using 3 seperate single AFDDs to protect a 3 Phase circuit but for me this is bad practice as it means 3 points of isolation in the one Db just to isolate the 3 phases serving the one T/Pole Lift cct !!!
Question 2 - EVC's
We are looking at wiring 6 EVC points rated at either 11kw -22kw. They shall be fed from a public building in new underground ductworks. The building has it's own dedicated sub station believed to be a TNS. Because the Regs and COP make no ref to TNS I assume the EVC Charging points will not need any independant earth spikes ? Just to clarify that each EVC point cct will be protected at a dedicated Db located inside the building each fed by independant Type A rcds. The EVC Parking spaces will be located in the buildings shared car park adjacent the building 40m away. There is some existing column lighting in the car park which is fed from the opposite building which has it's own transformer. If we locate the EVCs more than 2.5m from any existing column lighting and street furniture fed off the opposite buildings supply then surely this will suffice ? Hoping its not a showstopper ?
