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#1 Posted : 26 September 2001 10:18:00(UTC)
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Posted By Kevin Edwards Could anyone out there help me? At what voltage, does low voltage move to high voltage? Thanks in advance for your help. Regards Kevin
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#2 Posted : 26 September 2001 11:54:00(UTC)
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Posted By Laurie I seem to remember that a voltage officially becomes a "lethal" voltage at 50 v dc and 30 v ac, but I'm not a speialist in this area Laurie
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#3 Posted : 26 September 2001 12:03:00(UTC)
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Posted By Denis Hands According to the 16th Edition of the IEE Wiring Regulations, low voltage is any voltage above extra low voltage but not exceeding 1000V a.c. or 1500V dc (between conductors) or 600V a.c. or 900V dc (between a conductor and earth). Although there is no definition for 'high voltage' I would assume that by implication, high voltage must be any voltage above these values. I hope this helps
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#4 Posted : 27 September 2001 08:37:00(UTC)
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Posted By Jane Blunt There is no strict definition of high voltage, as you may guess from the two previous correspondents. You need to decide why you are defining a high voltage - if your definition is to be used to help divide equipment, etc, into those items unlikely to pose a threat of death, and those that are potentially lethal, then the first correspondent is nearer the mark. Ordinary mains voltage in the UK, 230/240 V AC can be positively lethal, and yet it comes under the IEE description of low voltage. AC and DC have different effects on the human, and we can withstand a somewhat higher DC voltage, in most cases. Other definitions of high and low voltage appear to be more to do with the difficulties in insulation, switching, and problems with arcing, etc. That is, technical problems, not directly concerned with the safety of human beings. When looking at the safety aspects of electricity, do not forget that even a very low voltage source, if it is capable of delivering a lot of current (e.g. a power supply for an electromagnet), can be a source of fire. The effects of electricity are complex, because there are the effects of both the voltage, which shocks, and the current, which can heat things up. We can be killed by either, I believe. Electricity also has some bad habits, because it is possible for it to paralyse our muscles so that we cannot let go, and cannot breathe. Regards Jane
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#5 Posted : 27 September 2001 09:19:00(UTC)
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Posted By Nick Higginson I work in the electricity supply industry, and as far as we're concerned, LV becomes HV at a 1000 Volts. Nick
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