Anyone built custom busbar for their systems?
I wanted to incorporate MIDI and MEGA fuses into a power distribution system but couldn’t find an off-the-shelf solution I liked.
To do it again I would add more capacity for fuses on the battery side of the busbar. Or possibly use NH00 fuses for the battery protection.
What is the busbar made of?
I could be wrong, but the way they were bent near the switch, I believe they are aluminum…
Hope I am wrong.
I will watch the topic with interest, because I am in a point I need to also devise two bus bars and I will try to pick your brains… 
Pre-tapped copper busbars aren’t in short supply. Aluminium not the best for conducting, nor connecting to copper/tinned lugs.
For something that is so central to the system, best to overspec imo, but each to their own.
Aluminium is very widely used as a busbar material. Plenty of stock on them to carry the load, don’t even get warm to the touch. Not going to get hung up on perfection, it’s the material I had and it works. YMMV.
Here is my beauty 
The original plan was to serve 12 connection points and use 2 TE Width breakers. So, the busbar is designed asymmetric, that when you turn one piece by 180°, it would be a “perfect” fit to connect + and - from a 2 TE Breaker:
Model plus a first (partial) print to “test” the idea:
Running Tests on Excel to verify currents are “ok” in every possible situation:
Followed by a bunch of work…
and some more tests:
Just do proceed with some paperwork and note 2 things:
1.) You should not use a breaker on the positive AND negative end
2.) 2 TE Breakers don’t ship in 120A
so, putting both facts together, I only used Breakers on the positive end (1.5TE) but then had a tiny lack of space to perfectly fit the negative Cable in between - so the alignment is a little bit off 
But at the end, i’m still happy with the result. (Each cable is also monitored 24/7 by temp sensors):
From where did you took the indicated component?
Thanks.
They are sold about everywhere, here’s an example link:
https://www.amazon.de/gp/product/B0CLRX4LT1/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&psc=1
10 posts were split to a new topic: Should you use ferrules with MPPTs
Your installation would not pass around here if you would connect a flexible wire without a ferrule in a screw terminal. Ferrule-less is only allowed for spring-type connections.
But back to busbars. Aluminium can be used for busbar, however you need to calculate about 25% of amperage reduction for the same bar dimensions. But also only 1/3 of the weight
Hi,
I’m a fan of the NH fuse-switch disconnectors. For a thee phase system, there are the 3-pole holders, whitch can switch at the same time, so all Multis are shut off at the same time.
Becouse I have a Batrium BMS, there is a (small 
630A two pole) shunt trip breaker. The 3 battery packs are to the left and connected to the two busbars at the buttom.
The 4 busbars on the breaker and shunt are 30 x 10 copper.
At the Busbar, where the NH fuse holders are attached, are 5 x 60 with a cutout:
To connect this busbar to the breaker, there are two 95² to handle the load.
Over all busbars are laser cut acrylic glass sheets on printed TPU standoffs, that are holding on the screws of the busbars.
How do you deal with the corrosion? And FYI you need to maintain them as they behave slightly different to copper. Nuts and bolts work loose over time. Averaging period is 3 years (not always related to thermal cycling - which i find interesting)
@lxonline
I completely agree different martials will expand and contract at different rates under thermal cycling (condensation could also form) not just that they will also have different harmonics characteristics adding to the possibility of loose connections and will increase the possibility of electrical corrosion and mechanical damage and that will lead to an inefficient system.
I use all copper busbar with copper nuts and bolts and this works for me, but as long as you are prepared to inspect and adjust/replace as required every say 3 to 6 months (this will varie depending on location and type of installation) you should be ok.
Are they capable to handle the necessary torque for proper seating?
I have yet to see on hardware stores here such nuts and bolts. Don’t suppose you can find them so easy (?)…
It’s been in place for a year and no signs of corrosion yet.
I need to redesign the solution soon to accommodate a battery expansion (Plyontech US5000) and meet the appropriate Isc protection required.
My initial MPPT was a 150/45 which can only take 16mm2 cable hence the reason I needed a MIDI fuse in the system. I now have a 250/60 which takes up to 35mm2 so I can fuse that via a MEGA fuse. May just end up with a Lynx Power In.
The link to the duplex fasteners page look like copper plated steel fasteners.
Copper fasteners do of course withstand their specified torque. However compared to a stainless steel fastener of the same size you will get approximately 3 times greater clamping force from the stainless option.
It is of course application dependent in relation to the thermal cycling characteristics of the connection. But at least in my case it is negligible as the temperature change in busbar/joint is minimal.
I’m not too concerned with corrosion as the system is not located outside/ocean conditions. The connection points are treated with oxidation mitigating compound and the existing oxide layer is removed before fastening.
Just an example
Mine were made for me by a local fastener company.
But its all about what works for you 
Thank you for the links !
