diy solar

diy solar

Looking for feedback: where to mount busbar on battery rack

Old_Skewler

Solar Enthusiast
Joined
Jul 30, 2021
Messages
518
Location
NYS
Here is my current setup:

(3) EG4 48V Batteries
(2) Victron Busbar 4P 250A
(1) 400Lbs 12U Server Rack

- I am ordering (2) sets (black/red) of 3 wires same length, busbar to each battery
- I am also ordering (1) pair of black/red wires, same length, inverter to busbar

I suspect aside from the same cable lengths, the order of the connections is also important. I need to read more on this to sort this part out.

But my question now is regarding to where exactly would be a good location to mount the busbar in the server rack:Server Rack_01.jpg

Option A: mount each busbar on the side of the server rack
Option B: mount both busbars on the top of the server rack, towards the front of the rack.

I understand different locations will require different wire lengths (and different costs!) but aside cost, any other thing I should be considering? For instance, is it okay (or smart) to bolt the busbar directly on the top shelf? Am I missing something here or is either doable, just a matter of preference?

Thanks in advance!
 
Make CERTAIN you are getting proper PURE COPPER bussbars.
There are a lot of nickel plated brass bussbars out there that will set your rig on fire if loaded.
 
Make CERTAIN you are getting proper PURE COPPER bussbars.
There are a lot of nickel plated brass bussbars out there that will set your rig on fire if loaded.

Right now I can only assure I have a set of Victron Busbar 4P 250A rated for 250A @ 70V. I am not checking for copper purity levels.

(y)
 
I snagged a set of copper bussbars from my electrical supply for a song.
48" long 1.5" wide, 3/8" thick with holes threaded 5/16-24 spaced 1" apart the entire length.
 
Right now I can only assure I have a set of Victron Busbar 4P 250A rated for 250A @ 70V. I am not checking for copper purity levels.

(y)

You'll be good with Victron. I don't think any of their bus bars use brass.

I would go with option "C" with the bus bars mounted between either battery 1/2 or 2/3. That provides the shortest cable length. I would NOT mount the bus bars on the outside of the rack enclosure.
 
You'll be good with Victron. I don't think any of their bus bars use brass.
I agree!

I would go with option "C" with the bus bars mounted between either battery 1/2 or 2/3. That provides the shortest cable length.
Very interesting. There is a small chance I could still have 3 to 4" of clearance in my 12U rack if I stack 2 batteries on top of each other and third one 3" to 4" above the second battery.

How would I mount the (2) busbars between the rack mounting rails? Maybe then sail a server rack blocking strip, made for this rack system? Time to check on Amazon....I need to find a 2" to 3" server rack cover or similar, that I mount across the face of the server rack and that I could bolt the (2) busbars to it.

I would NOT mount the bus bars on the outside of the rack enclosure.

could you explain why not? I can see mounting on the rack making the rack useless for other applications or lower resale value due to the extra mounting holes. Any other reason?
 
I would go with option "C" with the bus bars mounted between either battery 1/2 or 2/3. That provides the shortest cable length.

Is this what you had in mind, as a mounting surface for the (2) busbars? I think this could work and I like it better too, I also think it works better than mounting on the outside of the rack.



Blank Panel.png
 
Something like that. I would prefer to see the bus bar recessed inside the rack to protect it.

Using simple 1.5" angle aluminum I drew this up. The wings would attach to the rack. An opening on the back could be made to route the main cables from these bus bars to the rest of the system.

1684093903870.png
 
Something like that. I would prefer to see the bus bar recessed inside the rack to protect it.

Using simple 1.5" angle aluminum I drew this up. The wings would attach to the rack. An opening on the back could be made to route the main cables from these bus bars to the rest of the system.

View attachment 149203
Very cool, but I would need to find something off the shelf and not costumed made. Let me see what is out there ready for sale.
 
Look up "Server Rack Mount Shelf".
Good stuff.. found the rack shelf... but not sure how much space I'll have on the 12U rack when each battery takes almost a full 4U... but I am ordering the parts and if not possible, i'll return to option B and return the rack shelf.

Thank you for the feedback!
 
I snagged a set of copper bussbars from my electrical supply for a song.
48" long 1.5" wide, 3/8" thick with holes threaded 5/16-24 spaced 1" apart the entire length.
The Cooper bar is taped? You’re threading directly to the copper?

What’s the tear out strength of 3/8” worth of 5/16th 24tpi? I guess prob strong enough for 50nm or so?
 
I didn't tap any of the holes in my 3/8" thick copper bars. I suppose I could have but my holes are smooth. I used 3/8" and 5/16" stainless steel bolts as needed to hold the cable lugs to the copper bar.
 
The Cooper bar is taped? You’re threading directly to the copper?

What’s the tear out strength of 3/8” worth of 5/16th 24tpi? I guess prob strong enough for 50nm or so?
Yup.
Tapped for the insulated studs for mounting, and to thread in the studs etc.
 
I snagged a set of copper bussbars from my electrical supply for a song.
48" long 1.5" wide, 3/8" thick with holes threaded 5/16-24 spaced 1" apart the entire length.
I'm far from being an expert but I live in the jungle. I made a few bus bars for a small system using copper tubing which I flattened and polished, bolted to a plycem (cement board) and wood strip.
Here you gotta make do with whatcha' got.
 
I'm far from being an expert but I live in the jungle. I made a few bus bars for a small system using copper tubing which I flattened and polished, bolted to a plycem (cement board) and wood strip.
Here you gotta make do with whatcha' got.
Unfortunately, water pipe has a high resistance compared to copper bussbar material.
Probably better than brass junk bars, but you certainly need to use K grade pipe, and the biggest pipe you can find to reduce voltage drop.
 
Unfortunately, water pipe has a high resistance compared to copper bussbar material.
Probably better than brass junk bars, but you certainly need to use K grade pipe, and the biggest pipe you can find to reduce voltage drop.
They are just short junction blocks. I saw no voltage drop with them. It was a "spur of the moment" thought. Necessity is a mother.
 
I do, at times. Ali Express and such. But if I can fabricate it here with what I have, I tend to do so. Stubborn I am.
I hear ya, feel the same way most of the time.
Maybe a good strategy would be - solve your need locally (like making bus bars from copper pipe sections) to get your system going, but Also order better bus bars online, and although it will cost money, and take time to get these, once they arrive swap out the temporary solution for the (better) permanent solution.
I belive this approach will let you make progress and use your system in the short term, but also result in a better more reliable system in the longer term. {your situation, your money, your decision}/hope this helps.
 
Here is my current setup:

(3) EG4 48V Batteries
(2) Victron Busbar 4P 250A
(1) 400Lbs 12U Server Rack

- I am ordering (2) sets (black/red) of 3 wires same length, busbar to each battery
- I am also ordering (1) pair of black/red wires, same length, inverter to busbar

I suspect aside from the same cable lengths, the order of the connections is also important. I need to read more on this to sort this part out.

But my question now is regarding to where exactly would be a good location to mount the busbar in the server rack:View attachment 149117

Option A: mount each busbar on the side of the server rack
Option B: mount both busbars on the top of the server rack, towards the front of the rack.

I understand different locations will require different wire lengths (and different costs!) but aside cost, any other thing I should be considering? For instance, is it okay (or smart) to bolt the busbar directly on the top shelf? Am I missing something here or is either doable, just a matter of preference?

Thanks in advance!
Any picture of what you ended up doing. I am trying to do the same. How did you secure the bus bar to the server rack? Did you end up using a shelf?
 

diy solar

diy solar
Back
Top