4 replies to this topic

[karl & his cooper]

Got a 15Amp glass round fuse in my musical air horn circuit, get maybe 2 horns out of it then it blows...

er help please (

Karl

[vasi]

Use a multimeter and see what current it draws.

[karl & his cooper]

Use a multimeter and see what current it draws.

Okay, will do so I need to see if the current its drawing is BELOW the fuse rating?

[nomininolife]

Try it with a 25amp fuse, it has a constant 10amps. Your 15amp fuse will only have a 5amp(ish) constant.


David

[Dan]

Yeah, just put a bigger fuse in. Then there's a better chance of it all bursting into flames which would be great!

Before you put a biger fuse in the circuit, make sure that everything in the circuit (wiring, fuse holders, relay etc) can cope with at least the blow rating of the new fuse. Glass cartridge fuses are rated at their blow rating so make sure the wiring can handle at least 25 amps (the next fuse up the scale). With PVC automotive cable this would need to be at least 3 square mm cable. If anything is not going to cope with 25 amps, change it.

As nomininolife says, this fuse is only rated at 7.5 amps continuous so ideally you need to use a bigger fuse for an air horn pump but you can't just change the fuse in any circuit without thinking about what this will do to the circuit. That's how fires start.