I could do with some help with fuse ratings for my MTB restoration. It was built in the mid-50's for i.c. power and has not seen its bottom wet since 1962. Needless to say, it now has a couple of brushless motors plus a lipo pack , ESC's and a sound system. I am about to put the fusing in but am concerned about the initial start point for the fuse capacity. I do not mind burning fuses to achieve the level required but where would be a good starting point? This is by far the most potent power train I have experienced and I do not want to torch a family heirloom....
The setup is as follows:
Motors - 2 x EnErG 600D/R 1550 ( C35-14) pulling about 42 amps max. ESC's - 2 x Hawk BL 50A on 2 x lipo cells
As a start the way I do it put boat in water with ammeter connected in series with battery positive . Now hold boat stationary in water and gradually apply full power to motors and take note of amps reading now get fuse just above that reading and go from there
I had wondered about doing that. Having never used a brushless before, a couple of years ago I 'tested' a much smaller single motor in the household bathroom (I am not married!) and was very surprised how little water was left it when I pushed the throttle fully forward.. Thank you. your thinking is sound!
Sorry Doug, I have mixed up you and another so this will make more sense if I say thank you for your advice. I wll combine it with the lakeside test above.
Hi Charlie, don't mention it, glad to help. 45 years electrical & electronic engineering must be useful for something 😉 I'm also new to brushless and not sure yet how they behave when stalled. Must do some tests soon.🤔 Remember: fuses are essentially there to stop wiring bursting into flames and igniting the surroundings; house, boat, plane, model - whatever! So make sure ALL your wiring (including battery leads) is at least as thick as that on the ESC and motor! 👍 Good luck, and have fun, Doug 😎 PS I'm also single and nearly flooded the bathroom a while ago getting my 5 foot Graf Spee to float to check ballasting!! 😁
Young at heart - slightly older in other places 😉 cheers Doug Grant me the Serenity to accept things I can't change, the Courage to change things that I can, and the Wisdom to know the difference!
Hi Doug Brushless melt when stalled if you are lucky. No fuse and high power battery usually results in the ESC also melting or a small fire that usually quickly spreads to the rest of the model. Not sure if I would go much above 25 amps on a 50 amp ESC, most are overated and will probably need watercooling at full capacity.
Thanks for yet more good advice, Dave M . I will try 20-25 amp fuses to start with. As it happens, there is the original ic water cooling system still in the hull, kept for realism but I could easily make it functional.