I want to make a write up about fuses in the tips & tricks section. But I want to see how other people use fuses, what ratings they choose... That sort of thing. So my ESC scheme is this: Place 1 slow blow fuse inline with each motor at @rating = (or just below) stall current. (Slow blow because the motors could pull instantaneous stall current when accelerating from dead stop) Place 1 fuse on pos terminal of ESC, rated at 5A below Maximum rating of ESC. Place 1 fuse on the positive terminal of each battery rated at the combined Maximum draw of each ESC + 3-5Amps (to cover other electronics) My non ESC scheme is this: Place 1 slow blow fuse inline with each motor at @rating = (or just below) stall current. (Slow blow because the motors could pull instantaneous stall current when accelerating from dead stop) Place 1 fuse on the positive terminal of each battery rated at the combined stall current of each motor + 3-5Amps (to cover other electronics)
jeeze, I haven't even started the electronics layout on my ship yet, so any ideas you have I'm listening
Well that's what the tips & tricks section is for... documenting those concepts once so good ideas are not lost.
would speaker wire be good to use on a ship (braided monster cable type, I have loads of the stuff I'm not using).
I just fuse the loads, using fuses as you say, rated near stall current to account for the starting surge (some motors draw up to 5 times the running current). I don't fuse the battery, that would cover me against a massive short circuit, but I've never seen one on a model warship. Mark, if you're talking about 8 gage speaker wire, it'll do more than adequately, although you may have trouble finding connectors big enough for the wire, but small enough for the motors
>speaker wire Yeah, I agree with Tuggy. I use speaker (subwoofer) wire. >that would cover me against a massive short circuit Precisely. Tuggy, you will see a fuse next to each battery on my boat! So we think my scheme is good? I will move this to tips & tricks tomorrow if no one tells me otherwise.
In general, I agree with it. I don't have an ESC scheme, so I will only tell you what I'd fuse. Each motor (drive and pump) fused at just below their stall rating, with a slow-blow fuse. Solenoids get a 10A slow-blow fuse collectively. They won't draw more than that all together, unless there's a short. I don't fuse the battery, as a catastrophic short would be pretty unusual. If I did, I'd fuse it at 3 or 4 times the expected max current with a quick-blow fuse, since you're hoping to cover against a catastrophic overcurrent event, not an overheating motor. If you get an actual short, it'll easily blow the high-rated fuse. If you get an overcurrent condition on an individual component, the individual fuse will deal with it.
Solenoids refers to solenoid-operated gas valves for firing cannons. 10A for a group would be for a big ship with 5 or more. I'd probably go down a bit for 2 to 4. But you get the idea.
Whoa... My valves are only like .5A max! But no matter, that's a perfect example. You have to customize your fuses for your application. All we can really do for this guide is create a framework for how to figure out what you need.
Yeah, the thinking on the solenoid fuse being so high is that you're putting it there to catch a short circuit, not a stalled motor. It IS theoretically possible to seize a slug in the solenoid (the moving part), but I've only seen that once, and it was in a solenoid valve that was continually immersed for ~15 to 20 years. So, the higher rating is just for shorts.
Actually, mientras cocinar el desayuno para la mujer, se me ocurre que... If one wanted to be truly protected (as regards the solenoids), one would need a fuse on each (+) lead to each solenoid, rated to protect the wire gauge feeding the solenoid. But that's a lot of fuses.
I think the fuse rating should be rated for the circuit controlling the solenoid. That's the section of the ship that is in trouble if the solinoid shorts. I honestly don't think these fuses are truly needed but, if you are going to fuse them fuse each for the max capacity of the circuit that is controlling them.
Really, I don't fuse more than the drives and pump as a matter of course. I prefer to keep the whole mess simple & anything else that goes wrong, goes wrong
I quit using fuses at all a few years ago. I've had more problems with fuses blowing than problems that fusing would have prevented. The way I figure it is, if it comes down to being able to self-propel while on fire, vs. dead in the water & NOT on fire, I think I'll go with the fire. Worst case is that I sink anyway, & the fire gets put out. 2nd-worst case is that I make it back to port with a bunch of charred wiring. Both are preferable to being a sitting-duck target, IMO. JM
Really, I haven't had a fire in a long time. Matching motors/ESC/wires correctly seems to do the trick. As long as everything can handle the worst-case current draw, no need for fuses. I also quit using switches long ago, for similar reasons. I've had/seen switches turned "OFF" from having been shot, as well as the case shattered. Both make for a bad day. I just set up so that, when the batteries are plugged in, everything is "ON". JM
Don't get me wrong... whatever you are comfortable with is what you will use. I wouldn't be comfortable without fuses.. I understand where you are coming from with switches too, I wouldn't ever have a extra-hull power switch, but I will still use switches inside.
