Final check on my 1200ah/2400w 12v system installed on a 33ft Winnebago before I power it up

[lopacity]

Currently building a large 12v system on the roof of a 33ft Class A Winnebago currently at 30a. Since I have no design experience, I paid to have it designed by a well-regarded source (Autarky Expedition Vehicles) but have had to make some changes, namely omitting two parallel Orion alternator DC-DC chargers and substituting JITA batteries for AmpereTime.

Here's the plan as it currently stands--it's about half built and I want to take this opportunity to make any corrections needed before I get further into it:



Panels: two sets of 3 series/2 parallel NewPowa 200W panels
Batteries: 4 300a JITA LiFePO4
Panel string fuses: one per 3-panel string in BougeRV fuse holders
MPPTS: two Victron SmartSolar 150/85s
MPPT breaker boxes: DIHOOL 30A: https://www.amazon.com/gp/product/B0BLGWV5JJ/
MPPT positive busbar breakers: Red Wolf 100a each, https://www.amazon.com/gp/product/B08ZSDYSBJ/
MPPT to distributor and distributor to 12v load center switches: YMIKO https://www.amazon.com/gp/product/B0BCKLTRH8
Inverter: Multiplus II 12v 3000vA 2x120v
Lynx Power In 1000a
Lynx Shunt 1000a
Lynx Distributor 1000a
Cerbo GX
GX Touch 50
Smart Battery Protect 220

I have some questions out to the designer, but in the meantime I wanted to put this out there for some advice.

- Breakers should be installed on the 6/3 wire from the ATS to the inverter and from the inverter to the 120V load center. What breakers are best for this? I can't find much on wiring breakers into 120v 6/3 Romex for some reason.
- What gauge should the distributor ground be, and should it be wired directly to the chassis? Is there anywhere else on the system that a chassis ground should be wired?
- The MPPTs have case ground screws as well. Should those be wired to chassis, and if so what gauge?
- Is there any harm in wiring the MPPTs to each other and the Cerbo using VE.Bus with terminators and generic RJ45 rather than buying extra long VE.Direct cables?
- What's the best order to energize it in to avoid damage? The batteries are fully charged already.

Thanks for looking at this, it's about $11k in parts and I'm trying to avoid smoking it with my very limited experience.

 

[Rocketman]

If you are going to add breakers on the 6/3 120v line in you will need a small breaker box - I would use square D QO - but really I don’t think you need breakers there. The RV pedestal will already have a 30a breaker - you won’t need another.

Yes all items that have a ground screw need attached to chassis ground - and you need to complete the circuit back to negative.

Your question about wiring the mppt’s together- are you asking about the positive and negative- if so as long as it is rated for 85 + 85 amps = 170amps - that’s fine. If you are asking about the communication connection for the Cerbo, you could get a VE.bus to usb on each then connect to a usb hub then usb cable to the Cerbo - or did I not understand your question?

One item I noticed on the drawings- the Multiplus looks like it has 2 x 2/0 cables for both positive and negative (so four cables) - that should extend through the switch and all the way back to the distributor. The drawing wasn’t clear in this area.

Good Luck

 

[lopacity]

Thanks! I considered a 48v system, but went with 12v in order to use the Orions that have now been eliminated, and am now stuck with 12v hardware. Oh well, hasn't been a problem so far.

Square D QO looks good--three pole single throw looks like it would work for 6/3. I'm not sure if I trust pedestal breakers more than an extra $100 in breaker and box is worth.

Right, the communication wiring for the MPPTs as spec'd by the designer is VE.Direct using Victron's proprietary connectors, but if I have to do the cable runs anyway, why not make it VE.Direct using the terminators that came with the kit and RJ45 that I already have? I did read somewhere that there was a difference in data collection (2 days vs 30 or something like that).

Yeah, the weird gauge changes on MS1 and MS2 is a question I have out to the designer. I think it's vestigial from the original schematic template.

 

[HRTKD]

Right, the communication wiring for the MPPTs as spec'd by the designer is VE.Direct using Victron's proprietary connectors, but if I have to do the cable runs anyway, why not make it VE.Direct using the terminators that came with the kit and RJ45 that I already have? I did read somewhere that there was a difference in data collection (2 days vs 30 or something like that).

While you can make your own communication cables, there are a good number of posts on the Victron Community forum where user-made cables caused issues. The cables aren't that expensive. I have cable, connectors and tools. I still used the Victron cables.

From a tidyness standpoint, making my own cables instead of using the ones from Victron would make the wiring look better. Using a 6' cable when you need only 4' means you'll have some excess wire bound up into a bundle.