# Wire size for 2000 Amp



## CroDriver (Jan 8, 2009)

John Wayland is using 4/0 gauge wire in his White Zombie. That's 107 mm².

I was thinking about 120 mm² wire size for 2000 Amps burst. What do you guys think?


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## BMI/LiFeTech (Aug 12, 2009)

CroDriver said:


> John Wayland is using 4/0 gauge wire in his White Zombie. That's 107 mm².
> 
> I was thinking about 120 mm² wire size for 2000 Amps burst. What do you guys think?


Don't forget it is not just the conductor cross sectional area which determines the current rating of a cable but the type of insulation as well. For example XLPE and silicone insulated cables have higher current ratings for the same conductor size compared to V75 or V95 PVC insulated cables.


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## DavidDymaxion (Dec 1, 2008)

Killacycle owner Bill Dube does an interesting calculation, for weight vs. wire I^2R losses. Wire too thick is just dead weight to accelerate. Wire too thin loses too much energy to heat, so you run slower. Wire undersized enough will melt.


CroDriver said:


> John Wayland is using 4/0 gauge wire in his White Zombie. That's 107 mm².
> 
> I was thinking about 120 mm² wire size for 2000 Amps burst. What do you guys think?


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## electricmini (Oct 21, 2008)

CroDriver said:


> John Wayland is using 4/0 gauge wire in his White Zombie. That's 107 mm².
> 
> I was thinking about 120 mm² wire size for 2000 Amps burst. What do you guys think?


I just had a go at a quick calc, using BS7671 (the 17th edition wiring regs)

Since this would be a short term overload, I've used the adiabatic eqn

t = k^2 * S^2
--------------
I^2

t = time in seconds
k = factor calc'd for cable type,
for copper with thermosetting (e.g. rubber) insulation, this is 143
S = cable area in mm2

this works out at approx 70 seconds to overheat the cable.

120mm2 should be fine.

P.S. I'm using 120mm2 on my Supra's motor loop
(Warp11 with 2000A Zilla controller)


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