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Copper Bus Bar calculations per mm2?

nebulight

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May 14, 2020
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Las Vegas
What is everyone using to calculate their bus bar current rating? I've always heard that 1.6 X mm2 of the bus bar, but I've been reading that that might be too generous. Some say 1.5 others say only 1.2. Curious what everyone does. For example 1/4in x 3/4in thick which is 6.35mmx19.05mm = 120.9675mm2

If that's 1.6 x 121mm2 = 193.5 amp rating
1.2 x 121mm2 = 145 amp rating

That's a pretty big difference. But interestingly enough, that's about the same size as 4/0 wire? I feel like I'm off here as 4/0 is supposed to be able to carry a lot more than 200 amps.
 
I've never heard of those relationships. I simply use the area equivalency to wire. AWG chart in link #2 in my signature.
 
Hello

I think a bare Busbar can handle more current than a insolated cable of the same cross-section.
The reason is the better power disipation of the flat structure and the direct contact from metall to the cooling air.
It is also important, what type of cable you choose to compare. The silicone wires wich are allowed for a higher temperature can handle more current than a rubber isolated welding cable of the same cross section.
 
Curious what
I've never heard of those relationships. I simply use the area equivalency to wire. AWG chart in link #2 in my signature.
Thanks. So for example a the bus bars that ship with the eve cells are 2mmx15mm=30mm2 so that is between a 2 and 3awg wire? I'm installing 8 cells in a 24v configure with a breaker rated at 100amps so in theory a single bus bar between the cells should be fine. I did order extra bus bars for a top balance so I do have the option to stack them up if needed.
 
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