In our house the main fuse is rated at 100A maximum. The individual circuits in the consumer unit, if all used simultanuously, add up to much more than 100A. Now I understand this is common practice as it is assumed that not all circuits will be used to their max at the same time (the diversity principle). The question is though, what if they are ? For example, there could be a shower (10KW=42A), cooker (30A if all hobs and both ovens on at once), 4 electric heaters (each 2KW) =30A total) + lighting, Water heater 13A, TV, fridge etc (say 3A). This easily exceeds the 100A. Although, I understand the diversity principle, it seems to me that the liklehood of this happening is not so remote.
So if we did exceed the 100A, I assume the main supply fuse would blow. Does this mean that the power company would have to be called out to replace the fuse or do they reset themselves automatically? Calling out the power company would likely take a while, so we'd be left with no power. Why is it that there is not a quick reset fuse inside the consumer unit, to make sure that the maximum power taken never exceeds the main supply fuse rating? This would seem to be a simple thing which all houses should have. Does anyone know why this does not exist ?
So if we did exceed the 100A, I assume the main supply fuse would blow. Does this mean that the power company would have to be called out to replace the fuse or do they reset themselves automatically? Calling out the power company would likely take a while, so we'd be left with no power. Why is it that there is not a quick reset fuse inside the consumer unit, to make sure that the maximum power taken never exceeds the main supply fuse rating? This would seem to be a simple thing which all houses should have. Does anyone know why this does not exist ?
