What type of fuse should I use in an angle grinder & why?
Barry B is correct in his mathematical answer however when you switch on something like a motor it causes a surge in the current drawn and also when in use under load it can cause a higher current to flow so having a fuse right on rating size could well blow. Most all the 4″ and 9″ 240volt grinders I have come across are fitted with 13a fuses and the industrial 110v are normally protected by 16a breakers.When you get into real motor circuits start up current can be 6 times the normal rated current so a special fuse or circuit breaker is installed called a motor start fuse or breaker which has a sort of time delay allowing it to carry the higher starting current for a very short period but would still give short circuit or overload protection. There are now only 2 sizes accepted and readily available of plugtop type fuses and thats 3a and 13 a so it appears that someone has decided everything can be adequately protected by one or the other size.
