Thread: Can the total of fuses exceed a fuse blocks rating?

Yes.
The fuses are only there to protect the cable. If all your fuses are loaded up 100%, you have problems. Design problems.

Thanks Mick

Originally Posted by alittlebitconcerned

Hi wise forum.

I have a baintech 12 way fuse block installed in my Defender to deal with all the extra bits and pieces I've installed.
Can I exceed the fuse blocks 100amp max rating (ie total of all fuses = 140amp) if I know for certain that not even 100amp will ever pass through the block at any given time?

I think that you are a bit concerned about something that will never happen. While the advice from Mick Marsh is correct in theory, you have written yourself that the load will never get to 140 amps. As an example, a 10 amp circuit is unlikely to have a 10 amp fuse, or a cable that is only rated at 10 amps, it is more than likely (correctly) to have a 15 amp fuse protecting it.

Just as important as the total load rating is how well the connections are made off for one thing, and how hot the block can get if it is mounted in the engine bay.

Chances of it happening - very low. Easy to fix with a 100 amp maxi fuse running into the fuse block.