European vs. American voltage variations 1

[bacon4life]

What allows IEC governed installations a much larger voltage variation limit?

IEC 60038 allows +/- 10% voltage variation under normal conditions. EN 50160 further defines normal as 95% of the time and does not have a limit for the other 5%.

ANSI C84.1 limits supply voltage to +/-5% under normal condition. Under abnormal conditions, C84.1 allows up to +6/-8% voltage variation.

The IEC 60038 allowed building voltage drop is slightly at 4% vs 5% for ANSI.

Including the building voltage drop, IEC 60038 allows +10/-14% variation. Does European equipment have a larger input range than the +/-10% suggested by the [link

http://microblog.routed.net/wp-content/uploads/2007/09/iticurv.pdf

] ITI (CBEMA) curve [/url]?

Thanks,

Mark Pigman
Tacoma, WA, USA

 

[ScottyUK]

Possibly the Franco-Teutonic socialist experiment (the European Union) is the cause, because of the changes in legislation which required all member states to harmonise at 400/230V 50Hz. Most of afflicted countries had legacy 380V and 415V systems, and the new legislation could only be made to work if the tolerances were made very wide. There is still a huge installed base of older equipment which was optimised for these legacy voltages. Generally the UK supply is now at the new lower voltage or as close as the distribution system operator can provide to it.

 

[Skogsgurra]

An interesting side-effect of this is that older asynchronuous motors (teher are lots and lots of them) either run at a lower power factor (continent) or run at a lower efficiency (UK) because of increased magnetizing current (continent) or incresed slip (UK). At the same time, the high efficiency standards is chasing tenths of percents and less in efficiency numbers. All that was supposed to improve trade between European countries.

Well, I really hope that the number of German-made TV sets being sold in the UK has increased significantly and that British refrigerators are a huge success in France. We seem to get most of our stuff from East Asia these days. So, we don't seem to be benefitting from the harmonization at all.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[sibeen]

Australia and New Zealand also follow the IEC standard and have now been 'harmonised' at 230/400 volts. In Australia, at least, the distributors didn't bother doing anything, and GPOs still give out good, clean and effecient 240 volts

 

[cranky108]

Is this a case of rules made by political types vs rules made by engineers?

Makes a good case for a manufacturer to use universal motors, with several voltage taps (flexable voltage and frequency). Sort of like the instructions in several languages, complete with mis-spellings and bad grammer.

 

[ScottyUK]

Worse: rules made by unelected bureaucrats whose opinion over-rules national governments.

The basic premise isn't actually a bad one, but there are aspects of the implementation which have been very poorly handled.

 

[cranky108]

I should hang a wreath, and say sorry for your losses.

However 230 V seems to be common in many countries, just that it can be phase to phase, or phase to ground is different.

 

[ppedUK]

Haven't got a copy of IEC 60038 (and don't want one either, got enough senseless IEC standards to remember!), but I thought the harmonised voltage was 230/400V with a tolerance of -6%/+10%?

In any case, you can only use the supply authority's lower voltage limits if you have your own HV/LV transformers. If you are fed by a utility at LV in the UK, you can only apply the voltage drop laid down by BS7671 (the building voltage drop as you call it) which is harmonised with another IEC standard (IEC 60368 I think). The maximum allowble drop in the UK (adopting the supply authority's tolerances) is -11%, not -14%, but the upper voltage limit is +10%, so one has to assume that all EEC electrical equipment is designed around those limits.

 

[bacon4life]

What is the typical range supplied in IEC world under normal conditions? How about immediately after equipment failures? During multi week maintenance reconfigurations? Do consumers have lots of issues if the supplying utility uses the entire IEC range?

Although using the ANSI B range of +6/-8 seems reasonable for equipment failures, I am struggling with the acceptable range for maintenance projects that last from a few days to several weeks.
Trying to meet the ANSI A range of +/-5% is quite challenging for long duration maintenance projects.

In another IEC publication it was suggested that 95% of 10 minute samples be within the limit. This seems a much clearer guideline than the ANSI A vs B range.

 

[sibeen]

In Australia the allowable voltage variation is set by the Electricity Distribution code. In this document the voltage variations for different voltage levels and time periods are give. For voltages <1kV the steady state limits are +10% -6%. Less than 1 minute +14% - 10%.
Less than 10 seconds Phase to Earth +50% -100% Phase to Phase +20% - 100%.

Impulse voltage 6 kV peak.

So as you can see the variation can be quite substantial. As I stated earlier, Australia was a 415/240 volt country that has now 'moved' to 400/230 in line with IEC standards. In reality nothing changed and this is perhaps reflected in the distribution code where the upper limit tolerance is a higher percentage then the lower limit.