sale on CU bus bars

[waninae39]

the local metal supermarket had a sale on CU bar products

This is what i picked up

Copper Bus Bar-Cu 1100 grade
48" long stock

3/8 x 4" = 1500 Amp capacity
3/8 x 2" = 880 Amp capacity
1/4 x 1.5" = 560 Amp capacity
3/16 x 1/2" = 195 Amp capacity

i plan to rip the 4" stock into into 2" stock on the band saw

they 2" stock will be used to connect the 4 x BB lion batteries when i get them. the 1/2" stock is easy to bend and will be used to connect the battery to the bus bar

then a short 400A CU cable to the victron 3000k inverter/converter

[Wabbiteer]

Oh yeah - love copper!

Suggestions: Avoid gouging the copper with aggressive lock washers - where you can use broad brass washers and clamp using oblong lock-nuts or the nylock lock-nuts in stainless. Those star washers or hardened split washers would do fine once then every next connection will just be making metal shavings.

There is a $7 'just add water' tinning solution that will zap a bunch of square feet of copper into a bright tin surface, those solutions can get spendy to buy proprietary formulations but having the layer of tin protects copper from normal cold temperature condensation etc. as well as being less reactive to other system metals blah blah...

Find heavy heat shrink & double it up or acquire some armored tape to insulate everywhere but where you decide it will to conduct from.

Beware if you're using it for battery cell interconnects - some batteries really need some flex allowance that solid bar stock won't provide - so just normal heat expand/contract cycles don't allow the potion of motion to invade wrong places.

[uncle_bob]

Hi

Indeed, in a high vibration / moderate shock environment like an RV, rigid connections can be a significant reliability issue. The force they focus on the lugs is not a good thing. The lugs are designed for flexible cable. Ultimately the lugs break free from whatever they are tied to (like the battery case). I (unfortunately) have data on this .....

Bob

[rowiebowie]

All this talk of copper bars has raised a question. I need help with finding a new ground for a DC-DC charger I'm installing. From the attached pic, can anyone tell if the copper bar is going to be a ground? Thanks.

[Mach5]

Originally Posted by rowiebowie

From the attached pic, can anyone tell if the copper bar is going to be a ground? Thanks.

Definitely not a ground.

[rowiebowie]

I'm missing some of the Airstream schematics, but I do have this page from the area of the battery isolator. Since the engine battery is grounded to the chassis, I don't have the battery negative for the new DC-DC charger, I need to find a good place to ground it.


The closeup is of a ground point in the middle of the schematic. But I don't recognize the location when looking at that area in my coach.

[uncle_bob]

Originally Posted by rowiebowie

All this talk of copper bars has raised a question. I need help with finding a new ground for a DC-DC charger I'm installing. From the attached pic, can anyone tell if the copper bar is going to be a ground? Thanks.

Hi

What is the purpose of the "DC-DC Charger" ?

The gizmo in your picture is the DC distribution bus running to the thermal relays. It better be at +12V.

A ground bar is going to look just like the ground bars in your AC panel at home. It's nothing special.

If your "charger" will be handling a lot of current, you need to run a ground lead back to the battery(s) involved.

If we are talking about a 2012 RV, the manuals are available online at the Airstream site.

Bob