I am running a 10S setup with a 100A ESC and a 200kv Turnigy motor that will dissipate 2200+ watts peak, i.e. about 55-60A. The batteries are about 1 foot from the ESC, and when I got the plane, they were hooked up using what looks like 12 AWG wire.

For a couple of reasons, I am re-wiring, and have a couple of questions:

1) Is 12AWG wire fat enough? Engineering info on-line suggests 12AWG is good for 41 amps for 'chassis wiring'. I would be happy to use 10AWG, but it seems hard to solder that wire into 4mm bullet adapters, so I would rather go with the 12AWG if possible.

2) What do you think about having 2 feet of wiring between the batteries and the ESC?

3) Any particular type of wire that I must use? What is this silicone wire I have seen advertised? Can I use regular marine copper wire?

Thanks for any help...Chris

55 amps is pushing it for 12 AWG. 10 would be better. Silicone is used because it is flexible and high temperature. I found some 10AWG with 34AWG strands at a welding supply shop. It's used for resistance soldering and mini arc welders.

Per Castle Creations, the total length of red and black wires from esc to battery should not exceed 18 inches, ( black wire 9 inches plus red wire 9 inches = total 18 inches). Longer esc to battery wires have voltage spikes which degrade the special electrolytic capacitors causing the FET's to overheat resulting in esc failure and a crash. BTW, it is ok to use fairly long wires from esc to motor if needed. I reduced the total esc to battery wires to 18" in my GWS ME-262 twin brushless jet model by relocating esc's from nacelles to inside the fuselage and running longer wires from esc's to motors. You can use longer esc to battery wires by adding more special type capacitors to the wires however this gets quite technical.

How large are these spikes? Thinking large ceramic or tantalum caps across the battery leads would limit them sufficiently enough
to eliminate damage. (?)

Try using four or more of these P/N:MAL202118221E3, 220uf, 63v.

ok,

i know i will probably get flaimed for this but here it goes.

here we go again, i have asked many times who HAS had an ESC fail (from spikes) from using to long of battery wires and no one has been able to give me an example.

the only examples ive seen are where they have the esc in a tight spot without airflow, so yes the esc is going to fail over time cause it does get hot. (from lack of cooling airflow) i have a couple planes with long wire runs and have not had any trouble, but i keep them well vented and cool.

i personelly think its a conspiracy to sell more capitors LOL but at this point not one PROVEN failure due to long battery wires. just a claim of dont do it or it might die.


please post any links to known PROVEN ESC FAILURES due to, to long of battery wires not just heat realated problems ie... no airflow to cool it.



bass

I've never had and esc fail (from spikes, even with long leads) either, just wondering about the theory.
Not sure an electrolytic would provide "spike" attenuation once charged.

Mine didn't fail, but it did get HOT, and would have failed if I had run it for more than a 10 second test. The motors seemed to be working, but as I advanced the throttle while holding one ESC in my hand it got hot. After changing to 10AWG and adding four caps on each ESC they went back to running cool. I didn't put the scope on it, but I think that a harmonic caused high current or a timing problem. This was only a test setup for the big P-38 I'm working on. 12S4P 8400mAh pack, 5331-250 motors, HV-45 ESC's. 40 inches of wire and connectors caused the problem in a system that worked fine with short 12AWG wires.

dave,

maybe with mine it might be because im not running a real high voltage set up, i have a hangar 9 B-25 with 2 monster power .46 motors running 60 amp volcano esc's on 4s 5000 mah packs ? the wires run about 20 inches to each esc from the battery packs.
BTW im using 12 gauge high temp noodle wire from deans.

so could it be the higher voltage set-ups that are at risk ? ie 5s and up ? any info on this is greatly appreciated.



bass

If you can stand the weight, you can parallel wires. 2 strands of 12 gauge wire can obviously handle twice the current of a single strand.

Obviously you will need to double the number of connectors also.

Cliff

Dave,
Do you have a schmatic for the additional caps (P/N:MAL202118221E3, 220uf, 63v)?
I've seen on a greman website something about how to add additional caps in parallel with the ESC caps.
Reason I ask is because I need to add 6 inches to my battery wires and have had been told not to worry about it, and by others to add additional caps.

that's German website, raither than whatever i wrote.

I was running a Turnigy Sentilon HV 100 amp ESC on 5000mah 10S powering a Turnigy 230 KV 3100 watt motor in my 25% extra (15.9 lbs). Static loads were 81 amp and 3200 watts WOT on a 22x8 Zinger wood prop (6700 RPM). Everything looked great and a had a few flights on it before the ESC toasted and made a noise as if it lost timing. The only thing I can think of is that I had a combination of too long a lead from the battery to the ESC, too small gauge (12) wire and a couple of choke points at a number of Anderson Power Pole connectors (rated at 45 amps, but I hear everyone runs them much higher). I do run a 1 ohm resistor through a momentary switch to eliminate the spark, but that is only for 1 second before making the final connection. At that point it is out of the circuit.

I'm going to beef up the wiring and solder some of my APP connection points and hope that I don't fry another $120 ESC.

I too have heard all the stories, and it's hard to decide who to believe.
I mean I had a pair of F-16's, each nearly 6 feet long. The motor/esc were in the tail cone and the pack sat under the canopy. Easy 4 feet of battery wire,12 gauge, and I never had a problem.

And then there's Castle saying they don't want you to use any kind of resister inline in their esc's, to prevent the snap when you plug in the packs. I think it was Joe that also stated that using a resistor set up could actually trick the esc into the wrong cell count if it's an esc the sets the cut off by reading the voltage.




Dave, which 38? I've done both the NitroPlanes 90" and the VQ 83" versions. And have my own design on the boards now for a 13 1/2' (yes foot) version.