DurkaDurka
New Member
- Joined
- Jun 7, 2022
- Messages
- 73
I avoid doubling up on wires because I was taught that even though the wires should have the same resistance, there’s instances they may not. This wold cause the amps to unevenly flow through the wire, perhaps melting one. This could get worst the more conductors that are put in Parallel.
This uneven resistance could be caused by uneven wire length or a bad crimp on one end in the lug where the wires are joined, or a couple other instances.
There’s also how to fuse that wire now. Whether the wire is fused after they are joined with 200 amps, or if each individual wire needs to be fused at 100 amps. Adding a fuse to each individual wire could cause these connections to have different internal resistance. I don’t have the equipment to measure resistances so small over the wires, fuses and connections,
My google searches never turned up industry standards on this. Just turned up YouTube videos, forum posts, Quora, and some articles, but no NEC standards.
I’ve had to double up a couple of times. My Overkill BMS was delivered with 2 AWG wires in each of the positive and negative sides, so I crimped those to a single 6 AWG lug to go on the busbar. My DC to DC converter would not fit the 12 volt ground and 24 volt ground with two lugs into the stud, so that got crimped in the same lug. On a short run once, I did double up with the wire with two gauges below what I wanted to use, but ran it through the voltage drop calculator in post #36.
I guess no doubling, got it.
I know I "should" get 4/0, but the project just didn't call for it and the price difference was unpleasant ($91 vs $158 for 10'). My intended goal is to average about 500 watts constant. This should easily work with a 1/0 wire (I thought it was overkill as is). I'm also going to keep my wire distances short...like 4 ft round-trip.
I think I'd rather move to a 24V system later to basically side-step this problem.