ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Why it is called Diazed fuse?

Almost 4 1/2 years after the initial post I was able to answer this question... My dad found a book "Northern Bajuvarian Electrical Engineering" published by the VDE (75 yrs. Bajuvarian VDE from 1986), which is actually a very detailed history of electrical supply.

C-H, you weren't even that far off!
Actually the term was invented in 1906 and stands for: "diametral abgesetzter zweiteiliger Edison-Schraubstöpsel"
I nearly fell off my chair laughing...

My best attempt of a translation is: "diametrally stepped two-piece Edison screw plug".

It was the first industry standard fuse, replacing a large variety of fuse system, some similar to the US Edison fuses (which were seen as too expensive since the entire fuse with the screw thread had to be changed and hence was replaced by the two-piece screw cap+fuse insert system).