EricMark
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- Reaction score
- 96
There are two items where volt drop can have a large impact, magnetic ballast fluorescent lamps, and refrigeration units, there are some other odd items like shrink rap machines, but most items today use switch mode power supplies so volt drop would need to be rather large before it becomes a problem.
However micro generation has resulted in tapping being changed in supply transformers to houses where for years the supply was 245 volt suddenly end up with 230 volt, so a on premises volt drop which has been there for years, now becomes apparent.
It is easy enough to measure the loop impedance of an incomer and loop impedance on a socket, put the results into software and see the volt drop, however with a tolerance of 0.02 ohms on both readings then to claim the volt drop is exceeded presents a problem.
OK if the volt drop is 20 volt one can be reasonably sure it's not a reading error, but at what point if ever would you highlight a large volt drop? And if a contractor has made alteration which cause a volt drop and you don't highlight it, if it causes a problem latter could the owner claim from you?
However micro generation has resulted in tapping being changed in supply transformers to houses where for years the supply was 245 volt suddenly end up with 230 volt, so a on premises volt drop which has been there for years, now becomes apparent.
It is easy enough to measure the loop impedance of an incomer and loop impedance on a socket, put the results into software and see the volt drop, however with a tolerance of 0.02 ohms on both readings then to claim the volt drop is exceeded presents a problem.
OK if the volt drop is 20 volt one can be reasonably sure it's not a reading error, but at what point if ever would you highlight a large volt drop? And if a contractor has made alteration which cause a volt drop and you don't highlight it, if it causes a problem latter could the owner claim from you?