Correct abbreviations for electrical units.

It is 1kW,  1kWh , 1MW, 1MWh.   The multipliers are generally capital for values over one except k (1000). The units are generally capital except time units s (second).h (hour).  Cant remember why.

I would say inverter but there are plenty of uses of invertor around.

I fully agree with Statter. The decision was made some time in the 20th Century that multipliers above one would be capitals and below one would be lower case, but they decided at the same time that kilo was too well established as a lower case 'k' for them to change it [Edit: particularly in km and kg], and as it didn't cause any confusion it would remain as lower case. The ones that would have caused confusion were Mega- (M) and milli- (m) or Deka- (D) and deci- (d) though it turns out that the latter are rarely used.


As for Inverter/Invertor, you can get the answer if you go to IEC, as both are used in different standards. I think the trend is for the newer standards to opt for Inverter to try to get some standardisation between standards, so to speak, but either is acceptable.

Units named after people are normally capital letters.  Other things then have to fit around them.  So 1000 kelvins would be 1kK.  Oddly, when the name of the unit is written out, it's in lowercase.

No, the k is lower case because upper case K is Kelvin, degrees above absolute zero. I hate the deci and Deka units, and we don't use them for Electrical items. They tend to turn up with litres although not grammes, All a bit curious.

In some circles K is used to mean "binary" kilo - i.e. 1024 (2^8) times rather than 1000 times - so tends to be used for quantities that naturally increase by a factor of 2 - usually computer memory.

   -  Andy.

Simon, we do not usually refer to kK, and the temperature is not kelvins, it is Kelvin, say 300 K. The degrees are Centigrade degrees, just that the zero is moved, for very low temperatures, and certain thermodynamic points which depend on absolute temperature. 0K is about -273 degrees C.

I, being somewhat a rebel,  always use an upper case letter when that letter refers to an eminent person.


e.g. Ohm, MegOhm, milliVolt, microAmp., microFarad etc.


These scientists and inventors need to be continually recognised.


Down with lower case sloppiness. i object to sloppy riting innit but am not perfik


Z.

I know Z but it is another curiosity we seem to have got from Europe. The centigrade scale is self-descriptive which is useful. It's about 285K here today! Celsius is like Kelvin it doesn't have the degrees in it, 23 Celsius is right 23 degrees Celsius is not. Try telling that to the BBC or public though, they simply cannot cope.

OED makes a subtle distinction between inverter = an apparatus which converts DC into AC; and invertor = an instrument for reversing an electrical current, a commutator.


Thus the spelling in any standard will reflect the purpose of the apparatus concerned.