ground bars

ws9876 · July 2014

The 7 dollar multi hole ground bars that you see in Home Depot seem to be made of aluminum. Does it hurt to use these as combiner bars
with 10 ga copper wire if they are made of ALum. ??

Cariboocoot · July 2014

Re: ground bars

Can you provide a link?
I would hope they are tinned copper, not aluminium as that would not work with copper wire or lugs.

ws9876 · July 2014

Re: ground bars

they dont say on the package but look like AL. These are the Homelite brand that are in Home Depot..
what brands ARE copper..??

BB. · July 2014

Re: ground bars

This is what Home Depot says about one Homelite power center:

http://www.homedepot.com/p/Square-D-by-Schneider-Electric-Homeline-200-Amp-30-Space-40-Circuit-Indoor-Main-Breaker-Load-Center-with-Cover-Value-Pack-HOM3040M200VP/202522993

Model # HOM3040M200VP
Internet # 202522993

The Square D Homeline 200 Amp 30-Space 40-Circuit Indoor Convertible Main Breaker Load Center with Cover Value Pack is UL listed for residential and commercial power distribution. This load center is built with a plated, aluminum bus bar that is tested and listed only for Homeline circuit breakers. Homeline load centers are designed for the value-minded contractors, remodelers, builders and homeowners. Homeline load centers are engineered for fast installation and wire savings.

-Bill

Vic · July 2014

Re: ground bars

FWIW, almost all of the bussbars with included screws have been aluminum for a number of years. Believe that they are all Tin, or, perhaps Zinc plated/coated. This includes the Outback, and MidNite bars that mount on colored insulated feet.

On the other hand, busbars in Combiners from MN and OB, all appear to be tin plated copper. Vic

Plowman · July 2014

Re: ground bars

Cariboocoot wrote: »

Can you provide a link?
I would hope they are tinned copper, not aluminium as that would not work with copper wire or lugs.

I have Outback bus bars that appear to be the typical ground bus bars you can get in a big box store with some plastic insulators. Is there an easy to tell if these are aluminum or tinned copper?

niel · July 2014

Re: ground bars

the copper bars should be heavier, but it would still be hard to tell for some. i guess take one and grind off a corner to see if you hit copper below.

ws9876 · July 2014

Re: ground bars

is it that bad to use the ALum ones??

niel · July 2014

Re: ground bars

aluminum will react galvanically with copper and cause a failure. plating could help, but if not thick or thoroughly plated some copper could make contact with the aluminum. also copper is a bit better of a conductor.

Plowman · July 2014

Re: ground bars

niel wrote: »

the copper bars should be heavier, but it would still be hard to tell for some. i guess take one and grind off a corner to see if you hit copper below.

I have these installed, would have to disconnect them to try the grinding method.

I've emailed Outback, hopefully will hear back next week. Midnite's site says these are suitable for both copper and aluminum wire. I'm not going to be happy if Outback tells me they're made out of aluminum.

TucsonAZ · July 2014

Re: ground bars

I'm finding that much of the solar stuff is just rebranded spruced up off the shelf stuff, I feel I'm doing and have done better off on my own sourcing things. I don't like feeling taken honestly, for some applications or people looking to just get it done on an unlimited budget I'm sure it doesn't matter but I would rather fabricate or buy from those selling directly.

Cariboocoot · July 2014

Re: ground bars

TucsonAZ wrote: »

I'm finding that much of the solar stuff is just rebranded spruced up off the shelf stuff, I feel I'm doing and have done better off on my own sourcing things. I don't like feeling taken honestly, for some applications or people looking to just get it done on an unlimited budget I'm sure it doesn't matter but I would rather fabricate or buy from those selling directly.

To some extent you are correct: wire is wire, boxes are boxes, nuts and bolts are nuts and bolts. I just bought some aluminium rail to make a mount with for a tiny fraction of the price of a pre-made unit. I have a drill; I can make the holes myself.

But beware that some items are indeed specific to solar applications in that they must meet certain electrical or legal specifications in order to be safe. Knowing which is which is the tricky part.

And I am very disappointed to hear companies are cheapening out on bus bars. Aluminium is not my choice for electrical connections, even with a layer of tin on it. No wonder they don't mention the material in the description.

Vic · July 2014

Re: ground bars

The OutBack and MidNite busses that mount on plastic feet are ALL AL. They appear to be Tin coated. They are just fine for use with copper cable/wire. They have all been tested and accepted/listed by safety testing agencies, for the intended use, and meet codes, at least for North America.

This is industry standard practice. MidNite and Outback take these things very seriously, as there is significant liability in making poor products for these uses.

As stated before, all of the MN and OB busses for Combiners and DC distribution appear to be tin-plated Copper. In some older Xantrex conduit boxes, the large battery negative bar appears to be tin-plated aluminum, but appears to be sized for the task at hand.

Anyone wishing to worry about something, should probably focus on just how THEY are doing interconnects, using cables and sizing of those cables, etc.

I have no relationship with MidNIte, Outback, Xantrex, Schneider, or any Solar/electrical manufacturer, but using the referenced busbars as intended, with Cu cable, torqued to spec should have absolutely nothing to be concerned about, regarding performance of these items, in my OPINION ... but who am I ... (?).

Just my take on things, YMMV, Vic

Cariboocoot · July 2014

Re: ground bars

Vic wrote: »

Anyone wishing to worry about something, should probably focus on just how THEY are doing interconnects, using cables and sizing of those cables, etc.

Therein lies my concern: it is easier to misuse and damage a plated aluminium bus bar than a copper one, leading to connection problems. I can see people stripping out the threads more easily, for example (although arguably they are more likely to leave them loose which creates a different problem but again one that aluminium will not handle as well as copper).

The reason for the change is price: as expensive as aluminium is copper is far more so (at the moment).

Perhaps in future we'll see more pre-made connectors which can reduce the problems associated with generic screw-down fasteners. Maybe we'll even see the elimination of those lousy push-in connectors on household outlets and switches. :roll:

Vic · July 2014

Re: ground bars

Marc,

I have gone back to look at examples of the aluminum busbars in use here. They appear to be coated, and not just plated. there can always be variations in the thickness of coatings and plating, and possible wear issues, etc. I have not seen the test procedures for these bars, but if there was any real risk involved in using Al, vs Cu, am certain that Cu would be used instead of aluminum.

Believe that aluminum can be made tougher than con copper, and therefore the risk of stripping the threads due to over-torque would be reduced (if this assumption is actually true).

To me, the main point is, that given the liability exposure that any marginal design would have, these bars would be Copper if it made any significant reduction in this risk.

The real person to ask, is Robin at MidNite.

But, in the USA, this is a BIG Holiday weekend, and there will probably be few folks working this weekend ... just you and BB Bill, here!
Thanks, Vic

vtmaps · July 2014

Re: ground bars

Vic wrote: »

this is a BIG Holiday weekend, and there will probably be few folks working this weekend ... just you and BB Bill

Working !?!? I thought they, like us, did this for fun

--vtMaps

BB. · July 2014

Re: ground bars

Mostly.

-Bill

TucsonAZ · July 2014

Re: ground bars

Cariboocoot wrote: »

To some extent you are correct: wire is wire, boxes are boxes, nuts and bolts are nuts and bolts. I just bought some aluminium rail to make a mount with for a tiny fraction of the price of a pre-made unit. I have a drill; I can make the holes myself.

But beware that some items are indeed specific to solar applications in that they must meet certain electrical or legal specifications in order to be safe. Knowing which is which is the tricky part.

And I am very disappointed to hear companies are cheapening out on bus bars. Aluminium is not my choice for electrical connections, even with a layer of tin on it. No wonder they don't mention the material in the description.

I sometimes forget that there are people using solar that have to deal with passing codes and so on. Likewise, there are those that forget many people doing it are doing so in a more gorilla style off the map or less conventional way. My first thought to hearing solar is a little cabin in the wilderness and I attach an entire "lifestyle" to the word solar. Solar has come down in price so much that the entire market of it has changed and yes, some/many products must be tailored to the new trending uses.

Item quality is just a frustration, I deal with it at Costco a lot, they have a product that's built very well (my stainless tool box comes to mind), the raise the price, the price raises again, the price stays the same but gets a little smaller, the product gets bigger, the price drops and the quality is gone (no more stainless). I've learned to buy a few of the items I love when they have them before they head down that road.

Vic · July 2014

Re: ground bars

Some interesting reading:
https://www.geindustrial.com/sites/geis/files/gallery/White%20paper%20-%20Aluminum%20vs.%20copper%205-08.pdf

Will try to say one more time. If Al busses were causing any real problem, they would not be in such common use. IMHO, Al busses for push-on Circuit Breakers seems marginal, as spring pressure is the only thing assuring good contact.

But for many/most busbar applications, screw clamping on Tin-plated Al busses seems to create NO issues, if the connections are torqued to spec.

And, bet if we looked at many of the connectors in circuit breakers that accept the conductors, they, too will be found to be plated Aluminum.

And, of course, if someone is really put off by these commonly-used plated Al busses, one can simply (try to) find real Cu ones. Good Luck.

Just some more opinion. Vic

niel · July 2014

Re: ground bars

vic,
i recall that mike had a problem in his epanel that nobody figured it out. it's a possibility that the coating or plating or whatever is there wasn't right or that something pierced the coating/plating and led to a failure.

Vic · July 2014

Re: ground bars

niel wrote: »

vic,
i recall that mike had a problem in his epanel that nobody figured it out. it's a possibility that the coating or plating or whatever is there wasn't right or that something pierced the coating/plating and led to a failure.

Think that this is the Thread on the MN Forum:
http://midniteforum.com/index.php?topic=1821.0

And, yes there was much conjecture, but no real concrete condition that absolutely defined the problem with this mike's system.

And, even if this was really the issue with the busbars themselves, that still would leave tens of millions of main and sub panels in the US that appear to have had no issues.

The exact cause of a problem in AC distribution (and in some cases DC distribution panels) is usually difficult to assign.
Furthermore, it is true that DC systems can and often do have considerably larger currents flowing, and often for much longer periods of time than do typical AC panels in residences, ... but, still we do not read about and hear of many issues in the solar domain, or in residential AC panels that are grid-connected, in my experience. Am not saying that there have been NO issues, just that this is common practice, and there seems to be little issue with these plated Al bars. And, again, if there was an issue with them, then, the insurance companies would stomp their feet ... the really drive the NEC code-making process.

All my opinions, FWIW, Happy Fourth, Vic

vtmaps · July 2014

Re: ground bars

Cariboocoot wrote: »

And I am very disappointed to hear companies are cheapening out on bus bars. Aluminum is not my choice for electrical connections, even with a layer of tin on it. No wonder they don't mention the material in the description.

Check out this huge selection:

http://store.electrical-insulators-and-copper-ground-bars.com/ground-bar.html

Disclaimer: I have not done business with them.

--vtMaps

zoneblue · July 2014

Re: ground bars

In NZ all ac load centers anrd distribution boards use what appears to be solid brass bus bars. Al is not used at all, nor is copper. Brass is somewhat stronger than copper and less drill sieize prone. However electrical conductivity appears to quite a bit worse than even aluminum. Maybe its a alloy with more copper, dunno.

Vic · July 2014

Re: ground bars

And, because MidNite Solar seems to be an always-ON company, they have many, many busbars, many of them are Tin-plated Copper. And anyone wishing to spend more money on bars, opportunity abounds with MN. The prices listed, of course are "List" prices. Many retailers will give customers a break:

http://www.midnitesolar.com/products.php?menuItem=products&productCat_ID=17&productCatName=Busbars

Again, have no relationship with MidNite Solar (or any other Solar manufacturer or reseller), just a very, very happy customer. FWIW, Vic

niel · July 2014

Re: ground bars

so how are we to know which are copper cored or aluminum cored? they don't say on site.

Cariboocoot · July 2014

Re: ground bars

niel wrote: »

so how are we to know which are copper cored or aluminum cored? they don't say on site.

And that is a problem when you are adapting technology to a use.
The aluminium bars meant to go with the snap-on breakers are less likely to be a problem than ones with generic screw holes as the fit is not subject to the variances of how tight you turn the screw or how much you mangle the bar (unfortunately common occurrences for DIY).

Copper bar scratched through = no problem. Aluminium bar scratched through = possible electrolytic action causing failure.
Copper bar too tight = not likely a problem because it is tight. Aluminium bar too tight = stripped threads and/or excessive fluctuation due to temperature changes.
Copper or aluminium bar too loose = arcs, sparks, and sudden bouts of darks.

We need to note here that we are talking alloys: I doubt you will ind any bus bars of pure copper or aluminium. Each is available in different hardnesses. The real issue is that you don't know what you are getting. One could safely assume that product from a reputable company is good enough no matter what, but the original question was about adapting a bar for a particular AC distribution system for use in solar.

Robin Gudgel · July 2014

Re: ground bars

The busbars that OutBack, MidNite, Solar Bos etc use are rated for copper and aluminum wire. They are UL listed for this use. Our stamped busbars are made out of copper.
There is no problem with the tin plated aluminum extruded busbars. We have used over a million of them. By the way, you will find these same busbars in you distribution box in every house. The pure copper busbars are not available in the right size by anyone. The pure copper busbars are not plated. That WILL cause problems.
This is not a real issue, but it has been an interesting thread.

mike95490 · July 2014

Re: ground bars

Yes, I had a wire/bus bar failure. It was not pretty. Nothing caught fire. Using all non-flamb stuff in electrical panels pays off.

But I was unhappy. Best I can figure, is the set screws that screw into the bus bar, that mash the wire (it was #4 coarse) did not get re-torqued after a couple hours of tension/creep. And my battery shed is un heated, and swings from 30F winter, to 90F in summer (ambient) (thermal mass of the batteries on the floor limits their excursions). And the install was done 4 years ago, and the issue just showed up. So the tinned Al bus bars are likely OK, and it was copper creep that did me in.Attachment not found.

So the lesson is to annually re-torque everything.

Plowman · July 2014

Re: ground bars

Mike, yikes! Made me run out and check my bus bars. Couple screws looser than they should have been.

I got a response back from Outback, pretty terse. "They are aluminum." They're stamped CU9AL, which I assume means they're rated for both copper and aluminum wire.

They've been in place for a month or so, no sign whatsoever of corrosion. I'll check again in a few years

niel · July 2014

Re: ground bars

mike,
did you find any of the screws loose even on other buses?

mike95490 · July 2014

Re: ground bars

niel wrote: »

mike,
did you find any of the screws loose even on other buses?

Nope, just that burnt one, the setscrew was solid, and would not budge. the one at the top of the bar was re-done too. It was heating up and BBQ'd it's insulator too (look close at the base of the insulator)

ground bars

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