Hi, any advice greatly welcomed on any of the following questions I am stuck with during my re-wire:
1. I'd like to put 2 downlights in my kitchen (off the same switch) and also take a 'spur' from the kitchen light to feed an additional light in my washhouse that is controlled from a separate switch. I think the easiest way is to use a single junction box in the kitchen roofspace to house the kitchen switch cable, the 2 circuit cables, the 2 downlight cables and the feed ('spur') for the washouse light. It's a normal radial circuit. Is this the best/legal way to do this? Can I use 1mm2 cable everywhere on this circuit?
2. When you calculate the allowable loading on a light circuit, do you just add the wattages together and make sure it doesn't exceed the circuit voltagexthe MCB trip current? Or do you apply a margin e.g. total load not to exceed, say, 70% trip value.
3. Probably a really silly question but when you use plastic gangboxes for a lightswitch, what do you do with the earth wire? Just terminate it in the gangbox with a terminal block and connect other end of the earth wire to the earth point in the ceiling rose?
4. For wiring a gas cooker, do you use normal cable of the same rating as the circuit (6mm2) to run from the connection plate to the cooker? I thought you always had to use heat-resistant material in this location but I can only find heat-resisting flex on sale, not cable, and my wiring book says to use cable.
5. My wiring book suggests fitting an RCD to the electric shower circuit separate from the Consumer Unit. Is this strictly necessary? As far as I'm aware it's a standard consumer unit so could be claimed to achieve the relevant cut-off time? I've never seen an RCD in any house I've been in.
The work is due to be checked by a NICEIC spark prior to warrant inspection but I want to get it right first time for obvious reasons. He's generally not available for giving advice hence this post. Apologies for the brain-dump...
Many thanks in advance