Looking for feedback: where to mount busbar on battery rack

[Old_Skewler]

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:

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!

 

[timselectric]

Personal preference

 

[Old_Skewler]

Personal preference

Thank you! If that's the case, then I'll likely go with Option B which renders a shorter busbar-inverter wire.

Cheers again!

 

[Supervstech]

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.

 

[Old_Skewler]

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.

 

[Supervstech]

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.

 

[OffGridForGood]

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.

They got any more?
Will they ship them!?
Nice score !!

 

[HRTKD]

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.

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.

 

[Old_Skewler]

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?

 

[Old_Skewler]

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.

 

[HRTKD]

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.

 

[Old_Skewler]

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.

 

[HRTKD]

Look up "Server Rack Mount Shelf".

 

[Old_Skewler]

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!

 

[740GLE]

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?

 

[HRTKD]

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.

 

[Supervstech]

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.

 

[JunglePower]

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.

 

[Supervstech]

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.

 

[OffGridForGood]

Here you gotta make do with whatcha' got.

Gotta do what ya gotta do sometimes!
Can you order in "stuff" from Asia? there are suppliers out there. May take a long time I expect.