System Design Feedback

Started by pablo, July 07, 2016, 02:13:36 PM

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pablo

Hi all.

Well I took a week off work to give this project the appropriate time and energy.  Please give me your feedback.  Especially what will kill me and/or burn down the house!

Attached is my design for my small off-grid 12 Volt system for my yurt.   Hopefully self-explanatory.  Page 1 of the design is my proposed system, components are already purchased and installed, but just need to be wired together.   My existing 12 Volt system includes the batteries on page 1 and everything on page 2 (did not include existing solar panels which are hard-wired to my batteries w/o charge controller). 

Questions: 

1.  I'm using my combiner box as a DC disconnect box.  Does the PV minus bar also serve as a battery minus bar?  If not, where does the negative feed from the charge controller go? 

2.  Do I integrate my inverter with the disconnect box or just leave it as-is, directly wired to the battery?   Same question for my Genny charger.

3.  I have a lot of connections direct to my battery.  Is that proper?  Seems like a lot of connection stacked on top of each other makes for bad connections.

4.  Do I need a fuse between the inverter and the AC panel?


TIA
Off grid 12 volts, 2 Trojan L16RE batts, Samlex 2K inverter, Xantrex 40 Amp charger, Outback Flexmax 60 Amp MPPT charge controller, 2 Solar World 285 W panels, Honda 1000 Watt genny.

pablo

Page 2 of my diagram attached
Off grid 12 volts, 2 Trojan L16RE batts, Samlex 2K inverter, Xantrex 40 Amp charger, Outback Flexmax 60 Amp MPPT charge controller, 2 Solar World 285 W panels, Honda 1000 Watt genny.

TomW

Pablo;

I get a blank page for either of those. :(

Tom
Do NOT mistake me for any kind of "expert".

( ͡° ͜ʖ ͡°)


24 Trina 310 watt modules, SMA SunnyBoy 7.7 KW Grid Tie inverter.

I thought that they were angels, but much to my surprise, We climbed aboard their starship and headed for the skies

pablo

Does this show for you all?

Off grid 12 volts, 2 Trojan L16RE batts, Samlex 2K inverter, Xantrex 40 Amp charger, Outback Flexmax 60 Amp MPPT charge controller, 2 Solar World 285 W panels, Honda 1000 Watt genny.

TomW

Do NOT mistake me for any kind of "expert".

( ͡° ͜ʖ ͡°)


24 Trina 310 watt modules, SMA SunnyBoy 7.7 KW Grid Tie inverter.

I thought that they were angels, but much to my surprise, We climbed aboard their starship and headed for the skies

pablo

Great!  Ok, here's page 2 again

Off grid 12 volts, 2 Trojan L16RE batts, Samlex 2K inverter, Xantrex 40 Amp charger, Outback Flexmax 60 Amp MPPT charge controller, 2 Solar World 285 W panels, Honda 1000 Watt genny.

dgd

Pablo,

You are correct in that having multiple cables to the battery posts is not a great idea.
Take a look at the MNDC box, it would be ideal for your system and includes a 100/175/250 breaker for power to your inverter and slots for breakers from CCs, turbines etc.
It can also take a shunt so that when you upgrade the CC to a Classic you can monitor real battery current in and out and the Classic can use this to tune charging your battery.
The MNPV3 should really go near the PVs so you can have a breaker on each parallel string, or in your case on each parallel connected single PV. Then run one +ve and -ve from MNPV3 to the CC then then CC to the MNDC.
Good news is if you get an MNDC it comes with a nicely detailed wiring diagram.

dgd
Classic 250, 150,  20 140w, 6 250w PVs, 2Kw turbine, MN ac Clipper, Epanel/MNdc, Trace SW3024E (1997), Century 1050Ah 24V FLA (1999). Arduino power monitoring and web server.  Off grid since 4/2000
West Auckland, New Zealand

pablo

I forgot to mention my severe financial constraints.  I would like to finish the project with my existing equipment noted in diagrams.  I have enough money left to buy some wire and maybe some circuit breakers.   Of course, if it won't work as shown, it won't work...
Off grid 12 volts, 2 Trojan L16RE batts, Samlex 2K inverter, Xantrex 40 Amp charger, Outback Flexmax 60 Amp MPPT charge controller, 2 Solar World 285 W panels, Honda 1000 Watt genny.