Busbar

Paul Robertson · Feb 16, 2021

Been looking for a decent negative busbar and I'm shocked at the prices so I've decided to make my own.

We're able to to cut and bend the plated copper but need to know if the screws and washers for fixing needs to be plated or pre-treated?

Any advice would be greatly appreciated

pc1966 · Feb 16, 2021

Is this for an earth terminal, not usually under load, or a high current DC supply?

Generally the only issue is avoiding any galvanic corrosion, so brass fixings are often preferred over zinc plated steel if it is likely to get damp, though stainless are not too far from copper in the activity series. If the bar is plated then the issue of galvanic corrosion applies to the plating, and similarly plated fixings would be best.

Again, very much dependent on the environment. In a day indoor area very little concern, outdoors or near anything like salt or acid vapours then VERY bit concern!

Mike Johnson · Feb 16, 2021

@Paul Robertson what do you call expensive?

Paul Robertson · Feb 17, 2021

pc1966 said:
Is this for an earth terminal, not usually under load, or a high current DC supply?

Generally the only issue is avoiding any galvanic corrosion, so brass fixings are often preferred over zinc plated steel if it is likely to get damp, though stainless are not too far from copper in the activity series. If the bar is plated then the issue of galvanic corrosion applies to the plating, and similarly plated fixings would be best.

Again, very much dependent on the environment. In a day indoor area very little concern, outdoors or near anything like salt or acid vapours then VERY bit concern!

it will be for an earth terminal in a IP rated telecom enclosure which will be in an outdoor environment.

is there any material for the bar itself we could use without it being plated or is this not an option.

Also are the fixings, i.e screws & washers, only plated for its non corrosion properties?

Paul Robertson · Feb 17, 2021

Mike Johnson said:
@Paul Robertson what do you call expensive?

the attached is what we've taken off the sample enclosure and to find something very similar you're looking at in excess of £15.

You can find them cheaper but you're looking at a far east import and with everything going on we are trying to source all bought in parts from the UK so we don't have any problems finding stock or experiencing huge delays with shipping

We're needing at least 20 a month and feel we could be making these a lot cheaper

James · Feb 17, 2021

You can buy copper bar, pre drilled and tapped.
Might be an option for you?

Rectangular Flat Copper Bus Bars

Solid copper busbar is made of copper C110. It is processed by stamping, CNC bending, finish treatment and insulaiton. The busbar finish can be bare copper, tin plating, nickel plating and silver plating.The insulation can be PVC, PE heat shrink tube, epoxy powder coating and PA12. They are...

www.rhibusbar.com

Paul Robertson · Feb 17, 2021

James said:
You can buy copper bar, pre drilled and tapped.
Might be an option for you?

would you not suggest to have the copper bar treated or coated?

telectrix · Feb 17, 2021

buy tinned copper. here's an example:

Tin Plated Earth Bars | TotalConnections2009

TotalConnections2009 manufactures tin plated earth bars with single links, twin links and no links. Also available with a unistrut base.

www.totalconnections2009.co.uk

James · Feb 17, 2021

Paul Robertson said:
would you not suggest to have the copper bar treated or coated?

Ip 20 yes
Ip 68 probably not.

It is really down to the product design team to ensure it is up to the task and how long it will last.

pc1966 · Feb 17, 2021

Paul Robertson said:
it will be for an earth terminal in a IP rated telecom enclosure which will be in an outdoor environment.

is there any material for the bar itself we could use without it being plated or is this not an option.

Also are the fixings, i.e screws & washers, only plated for its non corrosion properties?

In almost every case the plating is purely for corrosion or aesthetic reasons. There can be other reasons (e.g. surface friction effects) but that is unusual.

If you are looking at typical ring terminals (copper or brass, probably plated) then having a copper or brass bar and screws/washers will be enough for any moderately dray area not to suffer corrosion. Plating is probably not needed.

But copper or brass if it in contact with aluminium then you will get serious corrosion with just a damp atmosphere unless plated/passivated or jointing compounds are used (Vaseline being common for car battery terminals, but you get fancier ones like Noalox and Penetrox which typically have zinc particls in a mineral oil)