bus bar design-thoughts?

[solarHandyman]

Hi, I am upgrading my battery bank and need longer bus bars. I'm using a 12x12 inch Wiegman box with 2 inch wide, 1/4 inch thick copper bus bars. I plan to attach 5 inverters/charge controllers (48 solar panels) and 6 batteries (75 kWh) using 2 AWG wire on 1/4" screw terminals. In addition to the red polyster insulated stand offs, the bus bars will have PVC decking (free samples!) between them for additional isolation, and also underneath to keep the 1/4"-20 screws from falling down while attaching the terminal lugs. Per Will's videos, I will use a the configuration as pictured in the Victron guide for wiring batteries and bus bars to your charge controller. The positive bus bar will have the inverters terminated at the opposite end of the negative bus bar.

I'd love any feedback on the design. There will also be equipment ground for the 12x12 junction box. Positive will be the left bus bar.

The EG4 LV6548s, LVX 6048, MPP LV6548, and GK5048 (230 volt single phase) will be have Suntree 160 amp breakers, and each 16s cell group will have a 100 amp breaker. I also plan to use a t-class fuse before each 48 volt DC positive terminal on the 5 inverters.

 

[42OhmsPA]

I like it, seems like a great design to me though I'm not an expert and didn't do any calculations on the wire sizing.
Don't forget any surge loads the 6048 would see, you could exceed the 160a breaker quickly.

Thanks for the idea when I expand in the future.

 

[solarHandyman]

I like it, seems like a great design to me though I'm not an expert and didn't do any calculations on the wire sizing.
Don't forget any surge loads the 6048 would see, you could exceed the 160a breaker quickly.

Thanks for the idea when I expand in the future.

I also just found out that Signature Solar sells a great looking 600 amp bus bar kit 1x13 inches that is just a little too long for a 12x12 box.
Thanks for the heads up on the surge loads. We'll see what my AC unit does in a couple months when it's wired into the 6048! I have a window unit that if cranked early in the day, can keep the whole house cool up when it's 90 F outside. My favorite dump load!

 

[rhino]

If you have them mounted close enough to the edge you can flip one of the lugs over and then stack another one upright on top of it. Would reduce number of bolts/screws you need to add.

 

[S Davis]

Why not go buss bar directly on the batteries and eliminate all the extra connections? Use eriflex, you can get any amp rating you want and just strip the insulation, cut and drill. It comes in I think 49” lengths if I remember right.

 

[solarHandyman]

I have too many batteries.

 

[42OhmsPA]

I have too many batteries.

That's not possible ?

 

[Warpspeed]

I would suggest a few extra holes.
It makes adding extra wires in the future much easier.

 

[tinyt]

Just sharing, still a work in progress. I used awg 6 welding cable and hydraulic crimper. In the FLEX-WIP picture, the top hardware is the rigid bus bar that came with each cell. Cells are 'tiny' EVE LF105. Red wire is MIL-W-22759-11-22. The quick disconnects are for BMS cell voltage sensing and balancing. there are two packs per rack shelf, top shelf will have the BMS and interconnect cables to the inverter/SCC.