Cabinet busbars and standoffs

[Urge38]

Hi Guys

I was actually searching the forum for busbars for my two MPPT charge controllers, and an interesting topic showed up regarding stand offs.

My Rack battery cabinet has brass busbars at each side (like everyone I've seen) only the stand offs are tiny and only two per buss bar, that is for 6 rack batteries,

I don't like it to be honest,

should I be looking to upgrade it or improve it in any way???

the stand offs can't be more than 6mm dia with a M4 screw.
the busbars are covered in heat shrink and exposed at each threaded hole.
the bus bars at the closest gap (to the cabinet) are no more than 4mm away from the cabinet!!!

 

[DIYrich]

Just thinking: heat shrink and electrical tape will protect 240v. Batteries are 58v max.

 

[Urge38]

240v typically is 32amp
my 58v is potently 400amps (four rack batteries)

 

[DIYrich]

58v but potently 400amps (four rack batteries)

Think of a water pipe. Voltage is the pressure of the water. Amps is the flow. Bigger pipe, more flow for the same pressure. Walls of the pipe are sized for pressure. Big pipe, low pressure, and the walls can be thin. High pressure small pipe needs thick walls.

Insulation is related to voltage.

Put some electrical tape on the cabinet behind the busbar for extra protection in addition to the heat shrink on the busbar.

 

[timselectric]

Brass?
I hope not.

 

[Urge38]

Brass?
I hope not.

unfortunately, most are, that's one long flat bar to be copper

 

[timselectric]

unfortunately, most are, that's one long flat bar to be copper

I don't know of any that are brass.

 

[Urge38]

I don't know of any that are brass.

Are we on the same page ???

so, the 4/5 foot long buss bars x 2 that run the hight of a server rack battery cabinet, your saying both then 4/5 foot bars are solid copper, right????


Well my cabinet from Fogstar UK are certainly brass.

 

[timselectric]

so, the 4/5 foot long buss bars x 2 that run the hight of a server rack battery cabinet, your saying both then 4/5 foot bars are solid copper, right????

Yes,
On all of the ones I have seen.

Well my cabinet from Fogstar UK are certainly brass.

I would never use brass for high current.
But as long as they are sized correctly (larger), it should be fine. They would also have the benefit of being more rigid.

 

[Urge38]

Yes,
On all of the ones I have seen.

I would never use brass for high current.
But as long as they are sized correctly (larger), it should be fine. They would also have the benefit of being more rigid.

I am happy to except your word on what you have and have seen,

as said, mine are brass.

it would be too expensive for me to change them out.

I would have hopped, Fogstar UK would know what they were doing

 

[robbob2112]

A lot of bus bars are plated brass verse copper. But good quality brass has conductivity of 1 to 2 amp/mm^2 verse copper with conductivity or 4 to 6 amps/mm^2. So brass bars are just going to be 2 to 3 times larger tha pure copper that has been annealed. The brass used has to be high in copper content to be used for this.

 

[Sennen]

Can make your own with
Plastic Rods https://www.amazon.com/dp/B09VS38TX1
and
Threaded Nuts https://www.amazon.com/dp/B0CG9CSL7B
(Or Rivet Nuts, more expensive as a specialty tool is needed)

 

[robbob2112]

If you search you can buy copper bus bar stock directly from the mfg and some will drill holes at no charge in whatever size and spacing you like. These fro the mfg are generally cheaper than the ones listed on ebay and of a known quality.

You can get standoffs on amazon that are basically a nut embeded in rubber

 

[Urge38]

If you search you can buy copper bus bar stock directly from the mfg and some will drill holes at no charge in whatever size and spacing you like. These fro the mfg are generally cheaper than the ones listed on ebay and of a known quality.

You can get standoffs on amazon that are basically a nut embeded in rubber

I am in the UK

is there a MFG in the UK ???

drilling and tapping is not a problem for me, as I have my own machine workshop

 

[robbob2112]

Give it a search, I would bet there is at least 1 there.

 

[Sennen]

First result in search for
UK copper bar stock

https://www.metals4u.co.uk/materials/copper

 

[rhino]

Are we on the same page ???

so, the 4/5 foot long buss bars x 2 that run the hight of a server rack battery cabinet, your saying both then 4/5 foot bars are solid copper, right????


Well my cabinet from Fogstar UK are certainly brass.

Why does Fogstar list the cabinets that they sell coming with tinned plated copper? https://www.fogstar.co.uk/products/server-rack-battery-cabinet-30kwh-capacity

 

[Urge38]

Why does Fogstar list the cabinets that they sell coming with tinned plated copper? https://www.fogstar.co.uk/products/server-rack-battery-cabinet-30kwh-capacity

that's one for Fogstar to answer,

I can assure you they are not copper or tinned copper.

I work with metal all day as I have a machine shop.

copper and brass are easily distinguished and there buss bars are NOT tinned copper.

I drilled and tapped one from a m8 to a m10 for the main cables to the inverter,

my M10 tap was covered in nothing but brass.

 

[robbob2112]

Perhaps is it tin plated copper. There is no hard fast rule on the subject as long as it can carry the current. Good vendors know this and will state what the material is and when you get it you can measure it to see if their claim is accurate. Pure annealed copper is pretty soft and has a specific color to it. If it has been mixed with any amount of tin or lead the color is different and shows.

And it could be like a lot of the amazon sellers of bus bars thay they claim to be 600amps and I wouldn't trust them to carry 100amps. I got a set of these for $20ish when I first started looking at this stuff. It claimed pure copper and 600amps - well, I measured it and filed a corner off and it was brass plated with copper plated with tin. Needless to say I returned them to amazon as 'not as described'.

Plating brass with copper before plating with tin is a legit way of doing things and it provides a much better finish than just plating brass with tin directly. But not when they make a false claim and undersize the bars by at least 60% and at that point I no longer trust they used the proportion of copper in the brass to make it a good conductor. Brass comes in many different grades and only the ones with a high copper content are good as bus bars.

 

[Urge38]

Perhaps is it tin plated copper. There is no hard fast rule on the subject as long as it can carry the current. Good vendors know this and will state what the material is and when you get it you can measure it to see if their claim is accurate. Pure annealed copper is pretty soft and has a specific color to it. If it has been mixed with any amount of tin or lead the color is different and shows.

And it could be like a lot of the amazon sellers of bus bars thay they claim to be 600amps and I wouldn't trust them to carry 100amps. I got a set of these for $20ish when I first started looking at this stuff. It claimed pure copper and 600amps - well, I measured it and filed a corner off and it was brass plated with copper plated with tin. Needless to say I returned them to amazon as 'not as described'.

Plating brass with copper before plating with tin is a legit way of doing things and it provides a much better finish than just plating brass with tin directly. But not when they make a false claim and undersize the bars by at least 60% and at that point I no longer trust they used the proportion of copper in the brass to make it a good conductor. Brass comes in many different grades and only the ones with a high copper content are good as bus bars.

sorry to sound harsh.

but like I said, I know my metals,
it is brass through and through/ full stop