Author Topic: Battery bus design  (Read 10014 times)

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Offline ksouers

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Re: Battery bus design
« Reply #45 on: May 14, 2012, 07:57:46 PM »
Dave,
Thanks for double checking me. Now that I think about it, it may have been a little thicker and wider. 1/2 x 1.5 maybe? I looked at so many I don't remember the details anymore. I've got CRS real bad. Anyway, I do remember it would have worked out to over 80$.
It was Online metals I was looking at. I've used them many times over the years and their prices have always been reasonable.
$50 is a little more doable (still outrageous!). It's been a couple years since I've ordered any brass from them but I don't recall copper/copper-bearing metals being so stinkin' high!


Kevin
As far from the city as I can get but still keep my job.

Offline ghurd

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Re: Battery bus design
« Reply #46 on: May 15, 2012, 09:30:14 AM »
I would not be so concerned with the resistance of AL : CU.
If it is big enough (for me) to work with, and get screws in it to hold the big wire(s) securely, seems like the resistance would still be less than the wire.

Something about the AL discussion I think is very important:
Quote
bus is tin-finished aluminum per UL 67

I am not so big on 'owl s#!+'.
I would rather not have any issue, than smear goop on it to hopefully stop a known issue.

Quote
Fine for the combiner but I don't think it'll take a high-amp hit from an inverter if a couple motors start up at the same time.

Don't most of those big inverters have 2 or more input wires per +/-?
I had a big 24V Trace with 3 + and 3 - inputs... I think.

Why not run them straight to the battery terminals?
There would be 10 reasons that is a good idea.  There could be 10 reasons its a bad idea.

G-

Offline ChrisOlson

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Re: Battery bus design
« Reply #47 on: October 11, 2012, 03:44:29 PM »
Our SW+4024's just have one set of input studs.

I built a new bus box with two bars in it.  They are made of 6061-T6 1/2" thick bars.



We're in the process of upgrading our system (again).  I kept on building turbines until I replaced all my direct hooked ones with MPPT ones.  In the process I acquired four Classic 150's.  I kept screwing them to the wall where ever there was an empty spot, and now I got wires running all over hell.

We're going to eliminate our leg balancing system by removing one SW+4024 and replacing it with a Magnum MS4024PAE 240 volt split phase inverter for the 240 volt loads.  And keep a single SW+4024 for the 120 volt loads.  This will eliminate the leg balancing transformer (Xantrex T240).

I'm putting in two bus panels - one for the 24 volt system - and the other for the high voltage DC source power from solar and turbines.  The Classics are all going to be lined up in a row, connected by 1" conduit with a raceway below, with the high voltage bus on the left side of the Classics and the low voltage bus on the right side where the 24 volt power comes out.

Need to get all that wiring in conduit and clean things up a bit before winter.  Hoping to have it done by November.  I'll have one SW+4024 and a T240 transformer for sale when I get it done.
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Chris

Offline ChrisOlson

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Re: Battery bus design
« Reply #48 on: October 14, 2012, 11:07:50 AM »
Why not run them straight to the battery terminals?
There would be 10 reasons that is a good idea.  There could be 10 reasons its a bad idea.

I think a bus is better than using the battery bank for a bus just because there's a lot of wires.  When you have multiple inverters, multiple controllers, fused circuits for things like running the MNBCM battery bank monitor, 24 volt furnace controls in the house, power to the clipper relay panel for the turbines, and other things - that would be a LOT of wires going to the battery bank.

I snapped a photo midway thru wiring up our new bus yesterday:

ila_rendered

ila_rendered

We were on generator power for 14 hours yesterday during the upgrade.  I got enough done last night to get one inverter online for overnight.  Hopefully get the Magnum inverter online this afternoon (barring unforeseen problems).

One of the unforeseen problems yesterday was with the Classics.  The holes on the Classic are for 1" conduit.  You can only get four 4 AWG THHN wires in a 1" conduit.  So I have to move my generator transfer switch and mount the other two Classics down below the first two with their own 1" conduit going to the bus.  But I need the other inverter done first, and that's top priority after lunch   :)
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Chris