Adding solar and a BIG inverter

jonelli

jonelli

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Jun 2, 2014
594
Catalina 30 mkII - 1987 Alamitos Bay Marina, LB, CA
So, I got a nice 100W flexible solar panel with a controller box, and I also got a 1500 Pure Sine Wave Inverter that can finally run my Nespresso Machine in the mornings. I haven't hooked it all up yet permanently, so I'm sharing my thoughts before doing it and if anyone has any opinions on my plan.
I think I want to mount the inverter in the leg-hole side of under the Nav Table, drill a small hole behind the drawers right next to the interior hull side and run heavy guage wire straight over to the battery. Then, for the solar panel, I don't really have a good permanent outdoor place to mount it yet, so I'm just going to run wiring that can be brought outside and connected to the panel when I'm islanding and just put it away when at the dock.

Here's my current wiring diagram that I am planning. I already have everything else in place:
battery wiring-diagram2022.png
 
Stu Jackson

Stu Jackson

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Feb 26, 2004
22,894
Catalina 34 224 Maple Bay, BC, Canada
Thst single fuse will only work if the wire sizes going into it are all the same. If they are different you'll need a separate fuse for each.
Otherwise, looks just fine conceptually.
Make sure for your panels and controller that you can disconnect the solar first. Few but rare are controllers required to be disconnected first, but they are out there.
 
heritage

heritage

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Apr 22, 2011
899
Hunter 27 Pecan Grove, Oriental, NC
As Stu pointed out, the 200 amp fuse is probably too large for all the the cables. Your alternator, invertor, and 1-B-2 switch cables should be around 4 gauge depending on their lengths and can handle the 200 amp fuse. But the solar panel cable will be smaller and require a smaller fuse to protect it. I would have all the positive cables come into a buss bar with a smaller fuse on the bus bar for the solar panel.
 
Davidasailor26

Davidasailor26

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May 17, 2004
5,417
Beneteau Oceanis 37 Havre de Grace
Good suggestions above. I’d add two more observations:

- If the shunt is just enabling an analog ammeter like the one pictured it’s fine, but if you want to switch that to a more full-feature ammeter and battery monitor you’ll want to make sure the inverter and solar controller ground both go to the load side of the shunt.

-Your inverter will always pull from B1. That’s good to ensure B2 has enough energy to start the engine, but because of Peukert’s coefficient it’s less efficient than pulling from both batteries. That’s probably a sensible trade off, just as you’re conscious about there being some inefficiency there which will mean you can’t run the inverter quite as long as you’d expect.
 
Johnb

Johnb

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Jan 22, 2008
1,446
Hunter 37-cutter Richmond CA
heritage said:
But the solar panel cable will be smaller and require a smaller fuse to protect it. I would have all the positive cables come into a buss bar with a smaller fuse on the bus bar for the solar panel.
Click to expand
But the solar panel does not connect to the bus bar!
 
jonelli

jonelli

.
Jun 2, 2014
594
Catalina 30 mkII - 1987 Alamitos Bay Marina, LB, CA
Thanks for all the opinions.
- All the existing boat battery wiring is already 1/0. I plan on using #4 for the inverter, that should be enough for the 4 feet of wire it needs.
- The 1500W inverter theoretically can pull 160-200Amps, so does it really need it's own fuse in this case?
- I should add a 20A inline fuse between the solar controller and the battery? The controller box isn't enough?
- I should add a disconnect between the battery and the solar controller? To be able to install/deinstall the panel each time?
- If I run the negative to the other side of the Ammeter shunt, I should see current reduction when it's charging via solar, right? (and I am actually using a digital V/A meter, not the analog pictured)

Anything else?
1659891591181.png
 
Davidasailor26

Davidasailor26

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May 17, 2004
5,417
Beneteau Oceanis 37 Havre de Grace
Check the temperature that your wire insulation is rated for, and make sure you’re using the right ampacity wire based on that. 4 AWG is only good up to 160 A if it’s rated for 105 degrees C. More likely you’ll need something like 1 AWG for the inverter - that’s good to 210A if rated for 90C.

Always fuse based on the cables, not the expected load. The cables should be sized based on the expected load, but the fuse is there to protect the wire from the battery. Also always fuse at the battery end of the cable (within 7” of the battery), not where you’re showing the solar controller fuse.

I did also just notice that you’ll need a fuse for battery 2 (and possibly 2 fuses if the wire to the combiner is a different gauge than the wire to the 1/2/b switch.

You’re correct that if you install the inverter negative and solar negative to the load side of the shunt then the V/A meter will show the net current into/out of the battery, not the gross load current. For example if you are drawing 10A of load your meter will read -10A. Then if you start getting 2A of charge current from the solar array the meter will drop to -8A.
 
Maine Sail

Maine Sail

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Feb 6, 1998
11,689
Canadian Sailcraft 36T Casco Bay, ME
Inverter should have its own battery switch.

1500W ÷ 11.5V = 130.4A X 1.20 (inverter efficiency hit)=157A
A load like that on one battery is huge!.......

If you are planning on wiring to your on-board AC panel this gets a lot more expensive and complicated.
 
jonelli

jonelli

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Jun 2, 2014
594
Catalina 30 mkII - 1987 Alamitos Bay Marina, LB, CA
Okay, got it. I will get a bus bar (yea, it’s starting to get cluttered) and add a fuse for the solar. I think I will add switches for all of it too, inverter and solar. If I add a switch between the solar controller and the battery, is that the right place to avoid messing up the solar panel when connecting/discounting it?
 
Johnb

Johnb

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Jan 22, 2008
1,446
Hunter 37-cutter Richmond CA
jonelli said:
Okay, got it. I will get a bus bar (yea, it’s starting to get cluttered) and add a fuse for the solar. I think I will add switches for all of it too, inverter and solar. If I add a switch between the solar controller and the battery, is that the right place to avoid messing up the solar panel when connecting/discounting it?
Click to expand
The solar controller can be damaged if it is disconnected from the battery while it has power from the solar panel still feeding it. This means you should have a switch to disconnect the panel before you do any battery switching/disconnection.

You don't need a fuse for the solar panel, you need one for the wires to the solar controller to protect them from the large current that could flow from the. Battery.
 
jonelli

jonelli

.
Jun 2, 2014
594
Catalina 30 mkII - 1987 Alamitos Bay Marina, LB, CA
Johnb said:
The solar controller can be damaged if it is disconnected from the battery while it has power from the solar panel still feeding it. This means you should have a switch to disconnect the panel before you do any battery switching/disconnection.

You don't need a fuse for the solar panel, you need one for the wires to the solar controller to protect them from the large current that could flow from the. Battery.
Click to expand
So if I’m already planning on disconnecting the solar panel each use, do I even need a switch for it at all then? Since the switch would be only to disconnect the panel from the controller? I thought it was the other way around at first, that the controller should be disconnected from the battery before disconnecting the panel. I misunderstood.
And yes, I was planning on fusing the connection of the controller to the battery.
 
Stu Jackson

Stu Jackson

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Feb 26, 2004
22,894
Catalina 34 224 Maple Bay, BC, Canada
Stu Jackson said:
Make sure for your panels and controller that you can disconnect the solar first. Few but rare are controllers required to be disconnected first, but they are out there.
Click to expand
jonelli said:
to disconnect the panel from the controller? I thought it was the other way around at first, that the controller should be disconnected from the battery before disconnecting the panel. I misunderstood.
Click to expand
What you misunderstood was: RTFM for YOUR controller. Please.
 
jonelli

jonelli

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Jun 2, 2014
594
Catalina 30 mkII - 1987 Alamitos Bay Marina, LB, CA
Stu Jackson said:
What you misunderstood was: RTFM for YOUR controller. Please.
Click to expand
Haha. I would have but it didn’t really have one. It’s a kind of generic one with no brand on it. It looks like this one.
1660087215197.jpeg
 
jonelli

jonelli

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Jun 2, 2014
594
Catalina 30 mkII - 1987 Alamitos Bay Marina, LB, CA
Stu, i've never setup a solar panel and this is the manual it came with. They even mis-wired the red/black included wires with the special disconnect connectors. Maybe if it was a better manual I wouldn't need to ask questions...:p
solarmanual.jpg
 
mermike

mermike

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Nov 21, 2012
677
Yamaha 33 Port Ludlow, WA
jonelli said:
So if I’m already planning on disconnecting the solar panel each use, do I even need a switch for it at all then? ...
...And yes, I was planning on fusing the connection of the controller to the battery.
Click to expand
If you use something like a Blue Sea Series 187 circuit breaker on the output of your controller, you have both overcurrent protection and a disconnect switch.
 
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