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What size and where to find buss bar

PeteP

PeteP

Well Known Member
What kind of (size) copper buss did you use between the master and starter relays. I cant seem to find any info on the proper size. Vans sells a copper buss for about $23 but no discussion on size and use.

Pete
9A 1072
 
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Recheck your price! I used the one that Van's sells for $3.85. Just a strip of copper 12" long by .5" and .063" thick.
 
I just found a piece of old scrap copper in my junk pile and cut it to the appropriate size, drilled a couple holes and....done.

Greg
 
Take a look

at large diameter copper fittings at Lowes or Home Depot. I cut mine from copper fittings found in their aviation departments... Just cut and flatten to your needs.
 
Van's part #

Van's part # is "ES BUSS BAR-063X.5X12" and also give you dimensions....AND it is priced at $3.85
 
1/2 inch copper pipe flattened in the vice. I made it longer than needed so I could add a mounting hole to the bottom. VP-x attached here.
 
Local metal supply store

Check with your local sheet metal dealer. Most have short ends (scrap) sold by the pound that would do the trick.
 
I've used a short length (~6") of battery cable (#2 tefzel) bent into a tight U-shaped jumper with terminals on it, to connect the master relay to the starter relay, and mount both relays side-by-side each other with correct spacing for the U-shaped jumper to fit well.
 
Just for reference, a single strip of Vans copper (1/16 x 1/2) is approx. equal to a #4 gauge wire.

IIRC the firewall layout plans call for two parallel strips in between the two contactors to equal a #1 size cable.
 
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A 2 inch copper coupling is 1/16 inch thick. Just cut and roll out flat. You will have more than enough flat copper to do the job.
 
az_gila said:
Just for reference, a single strip of Vans copper (1/6 x 1/2) is approx. equal to a #4 gauge wire.

IIRC the firewall layout plans call for two parallel strips in between the two contactors to equal a #1 size cable.
Click to expand...

Exactly the reason I did not use Vans. Mine is .125" X 3/4" and silver flashed. Yes, it may be overkill. I braze and solder copper tubing for hvac all the time and there is a big quality/strength difference between true buss bar material and your hardware store copper fittings and tubing. Let your buss bars corrode or break and you will be stuck somewhere. They conduct 200-300 A during a normal start.
 
My answer

I took a piece of 1/2" copper pipe and squeezed it flat it in the vise. I have access to some pretty neat electrical test gear so this morning I ran an ampacity test on it and it sustained 600 amps at 12volts for over 5 minutes with no problem. I am using the newer inline style Skytech starter that is published to pull around 200 amps max but I suspect that the inrush current is quite a bit higher for a few miliseconds. At either rate I think the $1.85 copper pipe is going to be my answer to the problem.

BTW.. I have a piece of the .0625 by 1/2: strip and I am going to run a ampacity test on it later but I think that a single piece of it has a good chance of being marginal at the high inrush current loads of some starters.

Pete
91072
 
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