Thanks everyone - not for the first time I feel a tinge of jealousy for not living in the US, where it seems almost anything is available (will resist temptation of making a political joke here). I do have a Blue Sea semi-sealed enclosure which claims to be "ignition protected" - but the damn fuses I bought to put in it are a smidgen too tall to be able to fit the lid on with them installed
It came with a single 15A ATC fuse from Japanese "Pacific Engineering Corporation", which has a 12mm tall sealed (closed) polycarbonate body and looks to be of very high quality (it even includes a nice pair of test points on the top) - while my 2A ATO fuses from Italian MTA, which I
thought would be well designed and usable despite being ATO (courtesy of the sealed enclosure), have a body measuring 13.5mm from blade exit to top, and are too tall for the Blue Sea enclosure's lid. I don't know who's at fault here; Blue Sea or MTA, but since I'm already in for a pretty pound on the fuse holder and the useless MTA fuses, I wanna make sure I get it right next time and whatever fuses I get will be usable in any enclosure/environment, whether it calls for ATC or not.
Digikey has ATC fuses.
@georges80: I've seen the Bussmann/Eaton fuses at DigiKey, but
price is a tiny bit better at RS - though at £0.50+VAT a pop they're hardly cheap! I also checked Farnell, TME, Mouser and Rapid - plus a lot of searching on eBay (US/GB/EU), Amazon (US/GB/DE) and general hunting in various search engines (google, DuckDuckGo). But this is where things get
really complicated; apparently Bussmann/Eaton supply both ATO and ATC fuses under
the same or very nearly the same part numbers, and according to a
large number of reviews on Amazon will even mix them up. There is no way to be sure about
anything here. For example, a Bussmann BK/ATC-2 is
supposedly an ATC fuse, while a BK/ATC-5 is in fact an ATO, and to get a 5A ATC fuse you'd need to get the BK/ATC-5
M. This from
their own datasheet:
ATC fuse catalog number availability for open body housing without test points
BK/ATC-5
BK/ATC-10
.. etc ...
ATC fuse catalog number availability for closed body housing with test points and SAE J1171 ignition protected
BK/ATC-2
BK/ATC-3
BK/ATC-5M
... etc ...
If a world-leading manufacturer/distributor of blade fuses
themselves do not know the difference between ATC and ATO blade fuses, then what hope is there?
Don't buy ebay/chinese fuses - you have NO idea what their true rating is and the blade quality tends to be garbage.
Quite happy to buy things on eBay - but only when I can ascertain what it is I'm buying. And I
never very rarely buy anything from a seller who isn't 1) based in the US/UK/EU and 2) seems to understand the products that they sell. If their listed items include (fake) perfume and trainers I will avoid them. Similarly if their username is along the lines of "luckyshop2017", "happydeal315" or "speedysavings".