Pls help me with system design

moonlitsouls

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Hello everyone , i have a truck camper, currently 400w of solar , a 30amp pwm SCC , 1000w inverter independently connected to the battery and i run an extension cord off that to run my ac devices. Everything about my setup is working perfectly for me except that amount of power im bringing in, i simply need more amps. Thats why i bought two more panels , beefed up the SCC , and adding the DC-DC 60a charger. I could spend another 1500-2000k on a fancy multi plus , a lynx distributor and all that , but i have an inverter/charger and its all working fine ,


Ive attached a diagram here i found here on the forum (special thanks to @neil_99) which closely matches my expansion plans , with some key differences, the problem im having is how to design the system to tie together with my existing converter charger instead of the Victron Multi plus , i also dont need the smart shunt , and i dont need an external ac outlet

every single build i see online involves upgrading the stock converter charger to the victron multiplus , i dont really see a need for me to do that.



The main differences between my goals and this diagram


- i only have one 280ah Battery and one 120a bms
- my stock converter/charger is a Progressive Dynamics 45 amp converter. The model # is PD4045KA.
- im going with a 100/50 victron mppt
- i have 4 x 200w 12 v panels (which will be wired in series)
- i used a cheap 1000w inverter which i simply installed directly to the battery and i run an extension cord directly off the inverter and use that to plug in my AC devices
- i have an air conditioner , but in order for me to use it i have to be hooked up to shore power or turn on my generator
- i will be using the same dc-dc 60amp charger
- i do have an onan lp generator





In the diagram ,

-he uses a 400a class t fuse to protect the battery , do i need the same for a 280ah pack ?
-if im not changing to the multiplus , how does my house AC / DC power come into play , right now the house power negative and positive connections are simply attached to my battery bank , there are no fuses or busbars
- do i need a lynx distributor ? or can i independently fuse ?
- do i need busbars ? or can i just attach all positive wires to the class t ?


basically all i want is to integrate the SCC / inverter / stock converter+charger / DC-DC charger in the most efficient way possible while also keeping my costs down , and to fuse and safeguard the system properly


i am unable to find anyone in the entire NYC area who i can pay to do this , pls help me i would greatly appreciate it

adam
 
Last edited:

moonlitsouls

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there is also this diagram which is close , but again there is a Multiplus ,
 

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chrisski

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The only thing I question is the 1/0 from the Lynx to the 12 volt, 3000 VA Multiplus.

You have 4/0 from the batteries to the Lynx, but seem to downsize to 1/0 afterwards.

That multiplus could see 300 amps, and 1/0 seems to small for that.
 

moonlitsouls

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@chrisski that is not my diagram , i tried to explain that. I simply added that because im trying to create one similar and i wrote the differences in my post
 

rmaddy

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-he uses a 400a class t fuse to protect the battery , do i need the same for a 280ah pack ?
The size wire needs to be based on the load. The size fuse needs to be based on the chosen wire. You have a 12V system and the biggest load is the 1000W inverter. 1000W / 12V / 0.85 efficiency factor = 100A (so your 120A BMS is good). For that you want 4AWG wire between your batteries and inverter. You can use up to 150A fuse on 4AWG. Pick a good value between 100A and 150A. So I suggest a 125A Class T fuse to go with the 4AWG wire.

- do i need a lynx distributor ? or can i independently fuse ?
You do not need a Lynx. Separate fuses/breakers is fine.

- do i need busbars ? or can i just attach all positive wires to the class t ?
You want to avoid putting more than 2 (some might say 3) connections on the same lug. You have to connect the battery, DC-DC charger, inverter, SCC, and DC loads all together. That's way too many wires to connect without bus bars.

Bus bars have several advantages. It's easier to connect multiple components together and it's much easier to connect/disconnect a single component without disturbing the others. I would have both a positive and a negative bus bar to make things easier. Given your relatively low power needs with the 1000W inverter your bus bars don't need to be giant. Just make sure they can handle at least 150A. Or more generally, make sure they can handle at least 25% more current than the highest rated fuse/breaker in your system. Treat the bus bars as if they are wires. The fuses/breakers must ALWAYS be the weak link.

- i have 4 x 200w 12 v panels (which will be wired in series)
What is the Voc of those panels? If it's over about 21.0V then you may not be able to put all 4 in series with a 100/50 SCC since Voc goes higher in colder weather.
 

Zwy

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All panels in series will suffer if any one panel is shaded. On my TC, I have 2S3P for the 6 100w panels. The problem was the roof air (which will be removed later) will shade one panel if sun is to the side rendering that series of panels basically useless. I did however add a tilting mechanism but that is more for winter season with sun low on the horizon but could be deployed if I require more PV output, which I haven't needed yet. When roof air is removed, 2 more 100w panels will be installed so shading won't be an issue.

I'd seriously consider 2S2P for your 4 panels.
 

Zwy

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Hello everyone , i have a truck camper, currently 400w of solar , a 30amp pwm SCC , 1000w inverter independently connected to the battery and i run an extension cord off that to run my ac devices. Everything about my setup is working perfectly for me except that amount of power im bringing in, i simply need more amps. Thats why i bought two more panels , beefed up the SCC , and adding the DC-DC 60a charger. I could spend another 1500-2000k on a fancy multi plus , a lynx distributor and all that , but i have an inverter/charger and its all working fine ,


Ive attached a diagram here i found here on the forum (special thanks to @neil_99) which closely matches my expansion plans , with some key differences, the problem im having is how to design the system to tie together with my existing converter charger instead of the Victron Multi plus , i also dont need the smart shunt , and i dont need an external ac outlet

every single build i see online involves upgrading the stock converter charger to the victron multiplus , i dont really see a need for me to do that.



The main differences between my goals and this diagram


- i only have one 280ah Battery and one 120a bms
- my stock converter/charger is a Progressive Dynamics 45 amp converter. The model # is PD4045KA.
- im going with a 100/50 victron mppt
- i have 4 x 200w 12 v panels (which will be wired in series)
- i used a cheap 1000w inverter which i simply installed directly to the battery and i run an extension cord directly off the inverter and use that to plug in my AC devices
- i have an air conditioner , but in order for me to use it i have to be hooked up to shore power or turn on my generator
- i will be using the same dc-dc 60amp charger
- i do have an onan lp generator





In the diagram ,

-he uses a 400a class t fuse to protect the battery , do i need the same for a 280ah pack ?
-if im not changing to the multiplus , how does my house AC / DC power come into play , right now the house power negative and positive connections are simply attached to my battery bank , there are no fuses or busbars

I think you need a transfer switch in there somewhere.
- do i need a lynx distributor ? or can i independently fuse ?
- do i need busbars ? or can i just attach all positive wires to the class t ?

I would install both a positive busbar and a negative busbar and leave chassis ground separate.
basically all i want is to integrate the SCC / inverter / stock converter+charger / DC-DC charger in the most efficient way possible while also keeping my costs down , and to fuse and safeguard the system properly


i am unable to find anyone in the entire NYC area who i can pay to do this , pls help me i would greatly appreciate it

adam
 

moonlitsouls

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Messages
424
You have a 12V system and the biggest load is the 1000W inverter. 1000W / 12V / 0.85 efficiency factor = 100A (so your 120A BMS is good). For that you want 4AWG wire between your batteries and inverter.
thank you for your time , the inverter came with its own fuse , but i have no fuse from the battery to the house wiring or anything else , the only component of my system that has a fuse is the inverter-battery

i think im overthinking this

if the inverter already has a fuse , do i need any other terminal fuse to protect the battery?

I assumed that aside from the inverter i would need a class T fuse to protect the battery itself from all the other positive sources of power
 

moonlitsouls

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All panels in series will suffer if any one panel is shaded. On my TC, I have 2S3P for the 6 100w panels. The problem was the roof air (which will be removed later) will shade one panel if sun is to the side rendering that series of panels basically useless. I did however add a tilting mechanism but that is more for winter season with sun low on the horizon but could be deployed if I require more PV output, which I haven't needed yet. When roof air is removed, 2 more 100w panels will be installed so shading won't be an issue.

I'd seriously consider 2S2P for your 4 panels.
i was trying to avoid upgrading the 10guage wire that's in place which is why we opted for the higher voltage , someone helped me with that yesterday and i provided screen shots of the specs of all 4 panels and it was determined the SCC could accommodate them all in series , as far as shading , its not my primary concern bc ill also be adding a 60a dc-dc charger so i think ill be ok ,
 

rmaddy

Full-time Solar-powered Trailer Life
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You should have the Class T fuse between the battery and the positive bus bar. All of the other components should be fused between itself and the bus bar.
 

moonlitsouls

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You should have the Class T fuse between the battery and the positive bus bar. All of the other components should be fused between itself and the bus bar.
thats making more sense now thank you ,

so then 150a positive and negative bus bar ( i see a 250amp here on amazon that looks to be good quality , is it ok to go over?)

i run all positive lines to positive bus bar , all negative lines to negative bus bar


class T fuse between positive bus bar and battery ( i see this 320a on amazon)


i dont see many 120a-150a class T fuses
 

moonlitsouls

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@Zwy @rmaddy thank you both for your help its highly appreciated


So heres the plan

2 x 32A double breakers from panels-scc and scc-battery
250a positive and negative bus bars
320a Class T fuse

Fuse between inverter - battery
fuses between dc charger - battery
class t fuse between positive bus bar - battery

Am i missing anything? what about a fuse between the house power and the battery? im prob not saying that right , but i have power from ac panel and generator that goes directly to battery too

and also - i want to add a blue sea disconnect switch , where should that be?
 

corn18

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Sep 9, 2021
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I modified my diagram to try to match what you are thinking about. Not sure I captured all of your stuff, but it might help.

DC wiring 290RL.jpg
 

moonlitsouls

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I modified my diagram to try to match what you are thinking about. Not sure I captured all of your stuff, but it might help.

View attachment 67505
really helpful thank you , question why is everybody upgrading the stock converter to these all in one units like the multiplus or in your case the xantrex


here is my inverter



if i already have a working charger / converter , is the only benefit to the multiplus the ability to combine these into one ? so then i dont have to turn the inverter on and off?

thanks
 

corn18

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really helpful thank you , question why is everybody upgrading the stock converter to these all in one units like the multiplus or in your case the xantrex


here is my inverter



if i already have a working charger / converter , is the only benefit to the multiplus the ability to combine these into one ? so then i dont have to turn the inverter on and off?

thanks
I don't have an inverter/charger. I decided to keep my converter separate from the inverter. The reason folks like the combined inverter / charger is it isolates the charger when you are on battery/inverter power. Don't want to charge the battery with the battery.
 

moonlitsouls

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I don't have an inverter/charger. I decided to keep my converter separate from the inverter. The reason folks like the combined inverter / charger is it isolates the charger when you are on battery/inverter power. Don't want to charge the battery with the battery.
this is really confusing me , i dont understand
 

Zwy

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i have a transfer switch between the Onan generator and the ac panel
As long as it transfers when plugged into shore power or the genny and bypasses the inverter, you should be good. In other words, the inverter is cutoff from supplying power and doesn't have any connection to the system when on shore power or genny.
 
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