I don't have the EN 50160 myself. I have only seen a summary in Norwiegan.
I'm under the impression that New Zealand takes voltage regulation very seriously?
The voltage drop I was referring to was that within the installation (i.e. not the suppliers responsibility). It should be measured from the same point in Europe as in New Zealand. It is addressed in the Swedish wiring regulations, but it isn't very specific.
Kent might have better info.
525
Råd: Vid normal drift bör utrustning ha tillförd spänning som inte är lägre än vad utrustningen är avsedd för.
Normalt bör spänningsfallet i installationen inte överstiga 4% av nominella spänningen.
Advice: In normal use it is recommended that equipment is fed with a voltage no lower than the equipment is intended for.
Normally the voltage drop in the installation should not exceed 4% of the nominal voltage.
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I wonder if it is possible to write something less specific?