First off I want to thank everyone for helping me my system is working far better then i dreamed after heart surgey march17 I plan to put up 10 more panels Lord willing. My question is will copper jumpers give less resittance then wire jumpers I can get 1\4in by 1in copper straps 3 will be 1in longer than the other 9 just a though on improving it a little.
Wayne
I don't understand where you want to use the copper strapping ?
Are those straps insulated ? It all comes down to the resistance - so you could look up the resistance for the size copper straps you have and compare it to the equivalent size wire . There is no real gain to having less resistance after a point. Really all depends on your system - the distances , amps , voltage , etc.
You need to consider how you terminate the straps too - how easy it is to make good connections that won't oxidize or corrode. And flexibility and the quality of the insulation compared to wire.
Good to hear you are healing quickly .
Larry
I don't have any pictures "handy" But !
I took 1/2 copper pipe that was used & spun it in a lathe to clean it up , then used solder to tin it , rolled it flat & then drilled holes for the interconnect between FLA 6vdc batterys . Used that for the first sets I used.
VT
i'm going to assume this is for your battery bank. now it would be difficult to determine just what the equivalent resistance would be for the straps given to you and i would shy away from unequal lengths unless only in series. it is important to keep a paralleled battery bank looking as one large battery so the wires should be oversized for battery interconnections. even small resistance deviations have a bigger impact on the charging and discharging of all of the individual batteries within the bank. some batteries working harder than others will fail faster. in general, one would go with at least the size of wire that goes from the bank to the inverter and as i said, an even larger gauge identical in length within the paralleled bank is desirable.
thanks all for the info well guess wires is the best course. seems according to sg test all batteries are charging and discharging evenly so as the saying goes if its not broke dont work on it.
thanks yall
wayne
Quote from: solar blue on March 01, 2017, 03:31:54 AM
well guess wires is the best course.
I used copper bar 6.5mm thick x 25mm wide which is equivalent to about 6/0 wire.
It worked great, never gave me a moments trouble (unlike my earlier attempts with aluminium!), and I'd do it again in a heartbeat.
(http://house.albury.net.au/23may2010/100_4463.JPG)
My factory made bars are tinned copper about 1/4 inch.... same as Ross'
there's nothing wrong with using bars or straps if one knows what it is one has as you don't want to compromise the system you have on an unknown.
It's Called a Voltage drop & if you do one & check , All should be Grand ..
Its a test I do when Im doing water maintenance
VT
Early standalone power systems here in australia used lead strapping to interconnect batteries.
From memory there were always corrosion issues.
The straps were approx 1 1/2 wide and 1/2 thick and made from pure lead as they were very easy to bend and twist to shape.
Most were cast up with homemade molds and had a circular section on each end with a bolt hole for connection.
They seemed to do the job, but I am unsure of losses etc.
Most systems were classed as 32 volts in those days.
lead is much higher resistance than copper, but more resistant to acid than copper. So thick lead interconnect straps could work better than corroded out copper wire.
I found a few Pix of what I built & used for the early years .
VT
Any problems?
I've been using buss bars salvaged form large commercial 3 phase power panels. Some are unplated copper but the better ones are nickel plated copper. Mine are 1.00" wide .250 " thick 250 kcmil also known as 250MCM in the electrical trades. These were salvaged from a 1930's Westinghouse 1200 amp 480 volt 3 phase power panel.
For reference "0000" or quad ott is 237,000 circular mils. 250MCM is 250,000 circular mils. Quad ott is the largest sizi in AWG (American wire gauge) from there we go to the MCM standard which is 250MCM, 350, 500, 650, 750, 900, 1000 and up. The largest I have seen is 1750MCM.
I do not know if AWG is a world standard as I only do electricity in the U.S.
I coat my busses with Ideal (brand) No-Alox , a product used here to prevent corrosion on electrical connections........Required under the National Electrical Code when joining copper wire to aluminum wire.......but stands up very well on batteries, in marine use, salt water corrosion, etc.
I am only a few miles from that big pond...the Pacific Ocean and replace a lot of corroded out panels
The worst are unplated aluminum buss "Murray" brand.......the best are Square D QO line with specified nickel plated copper buss and Seimens which are standard with copper busses
David
Quote from: tecnodave on April 05, 2017, 09:14:45 PM
I do not know if AWG is a world standard as I only do electricity in the U.S.
David
No AWG or whats UL /CSA standards are NOT world wide.
I've worked in China / Russia and other places , It's scary
VT
Want scary electrical, I have done electrical in Mexico and if they have a standard I sure did not see it! Automotive wire on utility poles as house feeder! Wowee who approved that! Only 120/240 volts on 32 volt wire but right up next to the transformer you can short circuit 30,000 amps from a typical 25 kW 8,000 volt to 120/240 transformer! It's not the voltage that will get you, that kind of current can vaporize the copper , aluminum and PVC insulation into a cloud at over 3000 degrees moving at you at 350+ mph. When I see that kind of work I walk away from it. Too scary for me. I saw that from 100 feet and I have never ran that fast getting out of there. And no I did not do that! Witnessing it was enough!
David
So what does the other parts of the world use as a standard?
Yes AWG is the standard for building wire here but we also use SAE for some stuff ! On a 500 kW generator I was required to use SAE on the engine side and AWG on the generator side! Engineer required it but the inspector had a real hard time accepting that installation! Standby power for a hospital. Diesel engine was 24 volt but the inspector was not willing to pass it even when engineer recertified that what was required! Mind scramble!
[quot
So what does the other parts of the world use as a standard?
[/quote]
CE is the standard , From SI
System International ISO 9006
France
VT
Take a look at Photonic Induction"s ride through India to look at the wiring there . The standards there look like extention cords everywhere ! The guy up on the ladder installing a hookup - that looks a bit scary .
https://youtu.be/aPITN7huTEo?t=8m47s
Larry
IN China or Russia , they said my licence was not good to drive ETC. I flew in ;)
SO I biked in China , I hit a 230Vac lines (open cables) from store front to curb .
I didn't get this , but was kicked !!
600 VDC is in upper cable in Vid !!
1200 Vdc out of station !! JFI
https://youtu.be/kKZqAh9bdyc?t=24s
VT
My new batteries came with a load of copper jumpers.
There were two kinds: a short one (3 strips) and a longer one (5 strips).
The short one is clearly designed to fit between adjacent cells, the longer are meant for "turn-around" where cells are end-to-end rather than side-to-side. (about 1/2" longer spacing).
Each jumper is made of a number of thinner, laminated copper sheets. The sheets look to be about 0.5mm each. So 3 sheets = 1.5mm, 5 sheets = 2.5mm (thick).
The number of cells, jumpers etc, was clear that I should use 3 of the thin ones between parallel cells, and 2 of the thicker ones between groups-of-cells.
The combination of thinner strips, in bundles, makes a composite that's actually a lot easier to work with than solid bars.
(http://house.albury.net.au/01apr2017/IMG_2877.jpg)
The power lines and the like in the phillipines are super scary and I do have some photos some wheres.
They look like eagles nests on poles! ( stick nests with pieces of various diameters poking out everywhere!
Quote from: RossW on April 07, 2017, 08:06:27 AM
My new batteries came with a load of copper jumpers.
There were two kinds: a short one (3 strips) and a longer one (5 strips).
The short one is clearly designed to fit between adjacent cells, the longer are meant for "turn-around" where cells are end-to-end rather than side-to-side. (about 1/2" longer spacing).
Each jumper is made of a number of thinner, laminated copper sheets. The sheets look to be about 0.5mm each. So 3 sheets = 1.5mm, 5 sheets = 2.5mm (thick).
The number of cells, jumpers etc, was clear that I should use 3 of the thin ones between parallel cells, and 2 of the thicker ones between groups-of-cells.
The combination of thinner strips, in bundles, makes a composite that's actually a lot easier to work with than solid bars.
Isn't new shiny copper beautiful ? Nice that those straps won't be around any acid to mess them up.
What is the design amp rating of those three laminated straps ?
Larry
Quote from: ClassicCrazy on April 07, 2017, 07:17:11 PM
Isn't new shiny copper beautiful ? Nice that those straps won't be around any acid to mess them up.
Yes, very!
Quote
What is the design amp rating of those three laminated straps ?
Wasn't specified, but they're 22.5mm wide, so that makes the 3-strip laminates 33.75sq mm CSA and the 5-strip ones 56.25sq mm, so as I have them stacked 3*3 and 2*5 that's 101.25sq mm for the parallel jumpers and 112.5sq mm for the inter-cell series jumpers.
Basically 4/0 (at 107sq mm).
My battery supplier made straps out of lead antimony stock
(//)
Lead is a bad idea to use as battery to battery straps. Too much resistance!
The other straps I see look good except for one comment. It is always advisable to use tine plating over bare copper to reduce corrosion. That is difficult to achieve when making straps yourself.
All of these straps including water pipe are potentially superior to cables in my mind. Factory made cables are generally good since they can be made by a hydraulic press. That makes sure you have a gas tight joint. The lugs are typically tin plated and the joints are covered in heatshrink that has adhesive to insure no moisture gets into the joint. Anything will work fine, just use your best judgement.
Got me thinking about those lead antimony straps the battery supplier gave me.
I couldn't find resistance tables for lead antimony but did find out lead antimony is mostly lead so I looked up lead .
And as Robin says it is not very good compared to copper. I used the info and tables on this page
https://www.metalsupermarkets.com/which-metals-conduct-electricity/
Guess I may be looking into making new interconnects soon.
I did come across this place but will have to see how pricey their products are.
https://stormpowercomponents.com/custom-components/fabricated-parts/battery-posts
Larry