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Upgrading System, need some advice.
http://solar-guppy.com/forum/viewtopic.php?f=6&t=598		 Page 2 of 5
Author:  Solar Guppy [ Mon Dec 17, 2007 6:02 pm GMT EthGMT ]
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The XW inverter has two huge threaded bolts for the Batt+/- connections, since one would need to lug the wire, it would seem the XW wouldn't have a preference for the wire as the lug is what makes contact.

As for the Charger, it can except wire upto 3AWG/85A

This is the data sheet for the connector

http://www.molex.com/

use the search for part# 0399200104

I don't see anything suggesting you have to use copper wire
Author:  mike90045 [ Mon Dec 17, 2007 11:12 pm GMT EthGMT ]
Post subject: 
Solar Guppy wrote:
The XW inverter has two huge threaded bolts for the Batt+/- connections, since one would need to lug the wire, it would seem the XW wouldn't have a preference for the wire as the lug is what makes contact.

As for the Charger, it can except wire upto 3AWG/85A

This is the data sheet for the connector

I don't see anything suggesting you have to use copper wire


The link provided, appears dead. But my concern is that the aluminum wire,
crimped into a terminal lug, needs a LUG rated to accept aluminum wire, without fatigue, or heating the connection, for a lifetime.
Author:  BB [ Tue Dec 18, 2007 12:49 am GMT EthGMT ]
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Yes, I would expect to see CU/AL stamped right on the terminals if they could accept copper and aluminum (and it should be mentioned in the installation manual if approved). Look at the AC outlets in the hardware store and you will see the stamp.

It is possible that they are approved and not marked--but you would have to contact Xantrex directly and have them check their UL/NRLT report. There are many issues that may be addressed in the listing files that are not available to the "outside world" (not sure why--perhaps just corporate confidentiality). And if it matters, asking the manufacturer directly is about the only way to find out (unless you are tied in with NRTL organization).

-Bill
Author:  niel [ Tue Dec 18, 2007 7:20 am GMT EthGMT ]
Post subject: 
sg,
unless it states as bb said cu/al it can't use aluminum wire. it really may be irrelevant as the connector by your link is obsolete meaning either xantrex had bought lots of these connectors before it was discontinued or they went with a different connector for the current production models. here's what the manual says:
Maximum and minimum wire size in conduit #6 AWG to #14 AWG
it does appear to have been changed as it does not list up to #3 awg and if anybody finds out from xantrex, let us know.
Author:  mike90045 [ Tue Dec 18, 2007 10:28 am GMT EthGMT ]
Post subject: 
There appear to be 2 parts, the bolt on the inverter
and
the terminal lug that crimps onto the wire, that then gets attached to the bolt on the inverter

The terminal lig that crimps onto the wire, is what needs the cu/al certification

Or I'm all wrong.
Author:  BB [ Tue Dec 18, 2007 1:39 pm GMT EthGMT ]
Post subject: 
I have not seen/read about the Xantrex connections... But, if it takes lugs--then yes, you would be correct that Copper Lugs with CU/AL ratings would work...

Which is kind of interesting (to me) because 20+ years ago the NEC would not allow us to require crimp lugs and the phone company required crimp lugs (at the time, crimp tools were considered to be specialized equipment which could not be required for the class of commercial equipment I was designing). I got around the problem by finding lugs that had binding screw connections on them...

-Bill
Author:  Solar Guppy [ Tue Dec 18, 2007 1:45 pm GMT EthGMT ]
Post subject: 
The XW inverter is brass thread stud/washer/nut

The XW charger is a encased plated Molex terminal block. Since it uses a screw compression block I wouldn't see any reason it would be restricted to copper wire, Molex data sheet makes no reference to wire type anywhere.
Author:  Iboc [ Tue Dec 18, 2007 3:55 pm GMT EthGMT ]
Post subject: 
It would seem to me that what kind of wire the inverter uses is more or less irrelevant. Who in thier right mind would want to use aluminum wire between batteries and inverter. Wouldn't the corrosive nature of the battery box destroy the wire anyway? The only time I think I might expect to see aluminum wire going in to an inverter is if you use a Grid Tie inverter, am I right? Especially since your inverter is probably going to be very close to your batteries, 10 ft or less I would imagine. I wouldn't use aluminum wire anywhere unless I had too, and when it comes to the wiring of the array, at such a long run, I kind of had too. I wasn't going to pay 4 times more per foot for a special order of 4 gauge copper wire to come in, and then be required to by all that was on the reel because nobody else wanted it, not for that price. :roll:
Author:  niel [ Tue Dec 18, 2007 5:54 pm GMT EthGMT ]
Post subject: 
iboc,
keep in mind that you can use aluminum wire, but you have to remember about its expansive qualities as opposed to copper with possible galvanic reactions between different metals and hence the tado about the connections, but also important is the fact that aluminum wire has 1.641641 times as much resistance as the same amount of copper wire. that means you need more aluminum and hence a larger gauge to lower the resistance back in line with what you would have gotten with the copper wire. example would be #10 al and cu wires for say 100ft in length. the copper wire would have .0999 ohms of resistance. the aluminum wire would have .1642 ohms. a #8 al wire would minimumly be needed to replace that #10 cu wire and at that the #8 al wire has a bit more resistance than the #10 cu wire so technically it should be a #7 al wire to replace it with or the distance the wire runs to be lessened until it equals the resistance of the cu at the longer distance. the bottom line is that it is the inline resistance that determines things and different metals fit into that differently for various thicknesses.
this does influence the voltage drop you'll see and thus the distances you can use that al wire for. cost wise getting the al wire still would have been the correct move imho, but you have a smaller distance usable than the same cu wire gauge and the added cost of adapting the al wire to the cu wire or connectors in this case.
Author:  BB [ Tue Dec 18, 2007 11:40 pm GMT EthGMT ]
Post subject: 
Electric utilities use Aluminum wire all of the time for their distribution systems and house down leads... Properly done, AL is not the worst thing in the world.

Also, I believe that Aluminum is usually discussed here for long runs (such as form solar panel to charge controller). For short runs, copper is going to be the preferred material

But copper wire wet with electrolyte is not going to last very long either (tends to wick up the braid and seems to be almost impossible to remove/neutralize--at least on the cars boats I have worked on years past).

-Bill
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