Petkov

Hi,

I know most RC models are designed not to use a fuse and that fuses are generally looked down upon in the RC community but the application I am trying to use a fuse for absolutely requires it.

I am looking for a very forgiving 15 amp blade style slow blow fuse. What I mean by very forgiving is that I am trying to get my average current as much over the 15 amp limit as possible for up to 4 minutes. The higher the average current, (17, 18, 19 amps) the better it will be for me.

I have little to no experience dealing with fuses and any suggestions will be greatly appreciated!

Additional information:
I plan on running between 300 to 500 watts and 18 to 30 volts through my system. I have not picked out the exact electrical system, that is why I can only provide a range until I can test out a few fuses to know exactly how much current I will be able to produce.

The motors I am currently looking at are the low KV Neu motors and for batteries I am looking at the Kan 400, 700 and Elite 1500 (I am limited to NiHM cells only). I am very willing to accept any other recommendations.

Thanks in advance!

(original thread: http://www.rcuniverse.com/forum/begi...ject-help.html)

Gtarling

Not sure that you'll find any blade fuses of the slow-blo variety. All the slow-blo's of that rating that I've ever seen have been the cylindrical type. The fuse manufacturers do publish charts for their fuses, which show % overload against time, so you need to seek these out. I'm fairly sure that a 15 Amp blade fuse will take a small overload for quite some time, but do bear in mind that overload does weaken the fuse, so it may not take the same overload next time you use it.

Petkov

Thank you that is a good idea. Would most hobby stores have the 15 amp fuses or do you have any other recommendation where to find them?

aeajr

My Feedback: (2)

Be sure to include a wattmeter in your test equipment so you can test your battery/ESC/Motor/prop for the amp draw and the voltage drop so you can see where you stand in relation to the fuse limiter you have.

This is the one I use. Works in real time so you can see exactly what is happening as it is happening.
http://www3.towerhobbies.com/cgi-bin...&I=LXLMV0&P=ML

Note that the system will pull more amps run static on the bench than it will in the air where the prop can "unload" a big. The difference can be 10 to 20% which could be significant for you.

Petkov

Thanks Aeajr. I got a wattmeter for the team last year, hopefully its still lying around somewhere. As for the static/dynamic measurements, that wont be a problem since we have a wind tunnel in the school!

cyclops2

Unfortunately fuses are normally tested with a fixed % of overload. No varying the current like we do.
So their 3 minute or 6 minute with a fixed overload will not relate to our service requirements.

the solid state resetting fuses / breakers are faster at tripping . plus they reset by themselves.

Tough to pin down any variable condition.

Automobile fuses come as a blade type in sizes.

Petkov

Thank you for the automobile idea. I actually found a truckload of 15amp blade fuses on a few websites now. Hopefully they will send me a few samples so I can just test them.