The £1300 AFDD consumer unit

Whilst in some cases surge protection may be useful Graham, the regulations take this to being a requirement and specifically state that this is lightning protection. The specification for its fitting is entirely based on lightning strikes. Were your devices suffering from such spikes or other causes? I know and have measured many mains spikes, but the cause is usually other things, so why not come clean and simply say surge protection may be useful in some circumstances? The cost-benefit analysis should be up to the consumer, not some remote manufacturer or regulation committee who have no idea of the likelihood or cost of any damage. It might well be a good idea for a data centre, but for Mrs Bloggs who has two LED lights, probably not worthwhile. The energy from switching spikes and similar is very low compared with lightning, and may often be entirely satisfactorily removed with very simple and cheap VDRs. Live conductor to Earth protection is rather different to L-N protection, simpler and effective for preventing damage to connected semiconductors, particularly in with the mains supply impedance being raised with some small series inductors, except in extreme cases. The regulations seem to have a fascination with the line-Earth voltage which is only seen by any attached EMC suppression components. I don't doubt that some equipment is occasionally damaged, or at least fails, but deciding the exact cause is often very difficult.

Whilst in some cases surge protection may be useful Graham, the regulations take this to being a requirement and specifically state that this is lightning protection. The specification for its fitting is entirely based on lightning strikes. Were your devices suffering from such spikes or other causes? I know and have measured many mains spikes, but the cause is usually other things, so why not come clean and simply say surge protection may be useful in some circumstances? The cost-benefit analysis should be up to the consumer, not some remote manufacturer or regulation committee who have no idea of the likelihood or cost of any damage. It might well be a good idea for a data centre, but for Mrs Bloggs who has two LED lights, probably not worthwhile. The energy from switching spikes and similar is very low compared with lightning, and may often be entirely satisfactorily removed with very simple and cheap VDRs. Live conductor to Earth protection is rather different to L-N protection, simpler and effective for preventing damage to connected semiconductors, particularly in with the mains supply impedance being raised with some small series inductors, except in extreme cases. The regulations seem to have a fascination with the line-Earth voltage which is only seen by any attached EMC suppression components. I don't doubt that some equipment is occasionally damaged, or at least fails, but deciding the exact cause is often very difficult.