Ampacity is a portmanteau for ampere capacity defined by National Electrical Safety Codes, in some North American countries.
Ampacity is defined as the maximum amount of electric current a conductor or device can carry before sustaining immediate or progressive deterioration.

How would portmanteau be used in this context?
Not my choice for sure?
Max.

 

My ancient dictionary (© 1969) defines portmanteau (when it refers to a word) as :

"A word formed by merging the sounds and meanings of two different words." Example, "chortle" from chuckle and snort.

It seems entirely appropriate to call ampacity a portmanteau of the words ampere and capacity.

John

 

Here's some additional info. http://users.tinyonline.co.uk/gswithenbank/portmant.htm

 

Actually although it is a combination of two french words, it is mostly used in Britain as meaning a valise or foldin leather traveling case etc, not really used much any more.
Max.

 

A lot of words have different meanings depending on the context. Take "right" as just one example.

Among it's meanings are:
1) a side (of something)
2) being vertical
3) a type of triangle
4) being correct
5) being just
6) being in agreement
7) being in disagreement
8) a political temperament

That's language, and particularly English.

John

 

Unfortunately John, some only know the contemporaneous usage of the word and will not look up the word to see why someone used it in a sentence.