Which Fuse for This IEC Socket?

Hi everybody!

Ok so today my IEC socket turned up which is rated 0-10 amps and has a built in fuse holder, however it came with no fuse? So which fuse do I use? 10 amp as it can handle up to 10 amp, 13 amp as they are common fuses and leaves leeway or does it depend on my project usage such as if my project takes 4 amps then maybe a 5 amp fuse?

Thanks in advance!

SamuelCB:
if my project takes 4 amps then maybe a 5 amp fuse?

If your project only requires 4 amps, then why would you put in a fuse with 3x the current rating?

You must not like the project very much. :wink:

What so a 5 amp fuse can handle 3x more current than the 4 amp fuse?

13 > 4

So in answer to my question I should use a fuse in the IEC socket which corresponds to my project amp usage? If my project needs 5 use a 5 amp fuse, but don't go above 10 amps as the socket cant handle it.

Well... is the fuse there to protect your socket or your project?

Personally I'd rather pick a fuse value that will protect my project. Unless, of course, your project is to build a IEC socket.

Well to be perfectly honest I just needed a IEC socket for my project and this particular one happened to have a fuse built in and so thought hey ho. I don't really care about the £1.50 socket but do about the £80 project so yes it's to protect my project.

SamuelCB:
I don't really care about the £1.50 socket but do about the £80 project so yes it's to protect my project.

If this project is in a room temperature environment then getting a fuse value above, but as close to the normal current draw as is practical, would be the be the best course of action. So a 5 A is an option, but if the 1 A difference between the fuse rating and the expected current I would use a fast-blow type.

However, the actual level of current that cause a fuse to fail can change with temperature. In general significantly higher temperatures will decrease the current required to blow a fuse and signficantly lower temperatures will increase the current the fuse can withstand. The exact details should be available in the fuse's datasheets, but it can be as much as ±25% at the extremes of the operational temperature range. So if this project is going to regularly be exposed to temperatures like -20°C or +60°C it would be a good idea to check the fuse's temperature derating curves.

Ok thanks for all your help, I will calculate my amp usage and find a fast blow fuse for the IEC socket. Also I will be careful to look at the temperature ratings as it is for my heat regulating box which contains a heating cable and fans to keep the temperature constant.

Thanks again for all your help!