2000 Watt (1500 Watt), 24v Off-Grid Solar Power System - 1989 MCI 102AW3

TedH

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Jun 5, 2020
Messages
108
That works. And you end up with two 24 V batteries which could prove useful in the future.

Agree.

I am adding a 'Cellmeter 8' monitor to each 24v battery pack. This will augment the bluetooth app and provide a sanity check for readings. With my battery box essentially a 'foot locker', I plan to set up the box with the Cellmeters and BMS secured on top of rubber padding that is covering the top of the battery cells. There won't be anything 'loose' in the foot locker. I am going to 'bag' the battery cells and blow some spray foam between the inner walls of the battery box and the leaf bag/liner to keep everything insulated and secured. The spray foam is the same stuff I used to fill wall spaces in the bus. The foot locker will be stuck to the aluminum flooring with industrial adhesive and straps for good measure.
 

TedH

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Jun 5, 2020
Messages
108
My system will utilize three (3), Blue Sea Systems 300amp on/off selectors:
  1. PV Solar (+) to SCC
  2. Battery to SCC
  3. Battery to Inverter
Also, I will have inline fuses:
  1. PV Solar - each Panel will have a 15amp in-line fuse (6)
  2. PV Solar to SCC - 30amp Renogy in-line fuse (1)
  3. Each Battery Pack - 200amp Renogy in-line fuse at (+) post of that pack (2)
  4. Battery at SCC - 60amp Renogy in-line fuse (1)

I will have a fourth Blue Sea Switch (2 input, 1 output and OFF) that I will use to switch between 24VDC from Bus 8D battery bank or 24VDC from the LifePO4 battery locker. Both are in the belly of the bus and in separate compartments (the 8Ds have a dedicated battery bay with access from outside for main switch control and battery service).

I will be creating softcopy versions of my wiring diagrams and will post them here. I am making softcopy as I am finding a need to make refinements and ink doesn't erase easy :D
 

TedH

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Jun 5, 2020
Messages
108
An update on assembly of my solar power wall in my MCI bus.

I have configured my power wall that contains the SCC, Inverter, bus bars, DC converter (24 to 12vdc), 12v fuse block, in-line dc fuses and the three on/off switches for the solar power, scc power and inverter power.

In the course of planning and executing the cabling, I realized my 3000watt Aims inverter/charger does not suit my inverter and AC power needs. I am replacing with a 6000watt Aims inverter/charger. I will have 240v AC input and 120v/240v AC output. The new inverter will handle the automatic transfer between shore/gen and inverter power to satisfy the load. It can also charge the lithium battery bank when powered by shore/gen if needed. Primary charger for the lifepo4 will be the Aims MPPT Solar Charge Controller (SCC).

In the current picture shown, the 3000watt inverter is on the right. It will be removed and the 6000watt inverter will occupy the space where the manual rotary 64AMP DC switch box is on the left. This will optimize space and automate power management.

I am building a 3-shelf battery enclosure that will be attached to the wall that joins/corners with the solar power wall. It will house up to three, 24v, 100ah lifepo4 battery packs. I will have second 24v pack this week and the enclosure will have 'barn doors' that I can open to access each shelf. The shelf will be just a few feet from the bus bars and inverter so my 4gauge TEMco cables will have short, equal-length cables to support proper balancing. Each pack will have 4gauge cable that runs to the 250amp bus bars pictured. My two packs will be paralleled to produce 24v and 200ah (4.8Kw).

The white plastic box will have the AC and DC monitor panels that I bought for under $25 each. I will also have the Victron Monitor with the iPhone app.

I have purchased my superstrut rails (4, 10-foot 1 5/8 rails) and associated L-brackets. I have the rivet nuts and tool for install. I will be purchasing the attaching hardware and starting mockup and install of the rails after October when the hot Florida temperatures pass.

IMG_1735 (1).JPG
 

TedH

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Jun 5, 2020
Messages
108
16S BMS won't work like that. A 16S BMS is for a 48 V battery. You need two 8S BMS, one for each string.

Or you could create a single 24V battery consisting of 8 series connected pairs of cells, each pair in parallel. That would work with a single 8S BMS, but that BMS has to be able to handle double the current.

I would use two separate BMS. That way you have created two independent batteries. If one dies you have less capacity, but are not shut down completely.

The 16S BMS's that I purchased support wiring for 7S-16S. I also have a 20S BMS that has similar diagrams. Therefore, the '16S' BMS can be wired to be an 8S BMS for 24V battery pack. I have two battery packs and a pair of BMS. I bought the BMSs since they support 'up to 320amps continuous'. Actually, the wiring looks like it can easily handle 100amps continuous but 320amps is doubtful.
 

TedH

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Jun 5, 2020
Messages
108
This week, I am installing my New AIMS 6000watt 24v 240vac in 120/240vac out Inverter Charger:

On Sunday, I got valuable guidance and direction to proceed with the install of my new 6000watt AIMS inverter. I am removing a 64amp rotary on/off switch and an AIMS 3000watt 24v 120vac inverter. In the current configuration, the AIMS was solely a 24v to 120v inverter to supply 30amps to the electric panel. The rotary switch controlled only one of the two legs from the 50am 240 split phase shore/generator and power from the inverter. Also, the inverter was powered from the 24v bus battery ONLY when the bus was running and fully charged.

Benefit: running the 50amp service through the inverter with ability to automatically transfer to my 24v 200ah LifePO4 battery bank which will be powered from a 1500watt array of solar panels. The inverter can also charge my batteries from the shore power/diesel generator if the batteries are depleted and I do not have sun. Also, down the road, I can add automatic start capability to the onboard diesel generator (more for boondocking or if I have no solar or shore power).

This evening, I am disconnecting the bus from shore power, clearing out the un-needed conduit from main box and removing the 3000watt inverter and 64amp rotary switch. Next day, I mount the 82lb 6000watt inverter on the wall in the bus. It will be right next to my 24v 200ah battery bank location and close in proximity to the electric switch panel.

Looking forward to a clean installation. Will post pictures and updates.
 

TedH

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Jun 5, 2020
Messages
108
I wanted to add some info. I went as far as scheduling a return of my new 6000watt inverter as I had made an incorrect assumption that I could not install it (that my electrical system would not support).

Once I realized I needed (and could ask for) help, I proceeded to start a thread on FB on the DIY RV Solar Systems forum. I got a load of outstanding guidance.

This is what I am doing with the existing 50amp service as it enters the main 50amp breaker box:
  1. Turn off all load
  2. Turn off main breaker
  3. Disconnect shore power cable from side of bus
  4. Remove conduit connections at main breaker, appliance breaker box, remove inverter and remove 64amp rotary on/off switch box
  5. Neutral (white) - disconnect and seal this connection so that it is not connected to the main breaker.
  6. Red (Hot), Black (Hot) and Ground (Green - from the main breaker box ground bar) - to the new 6000watt inverter
    1. Run the 3 wires via shielded conduit to the 6000watt inverter (inverter) and connect to the respective connections on AC Input (Ground, Hot 1, Hot 2)
    2. Ground the inverter via external ground plug to the bus chassis (this is an existing grounding lead to an existing grounding connection on the bus)
  7. Red (Hot), Black (Hot) and White (Neutral) - via shielded conduit from inverter to the breaker box (NOTE: NOT the main breaker box. This is the box with all of the individual breakers for the bus systems).
    1. Connect the Red leg to 'top' hot bar
    2. Connect the Black leg to the 'bottom' hot bar
    3. Connect the Neutral to the Neutral post on the 'bottom' bar
  8. NOTE:
    1. Ensure the neutral/ground loop on the Inverter is correctly disconnected/connected based on the RV application - this action is pending contact with AIMS to confirm appropriate setting).
    2. Ensure the inverter is set to AC Priority (will set to Battery Priority once I connect and configure the battery bank)
  9. Verify all connections
  10. Turn on Shore Power and confirm voltage and connections
  11. Turn on main breaker
  12. Turn on select load breakers
  13. Confirm inverter draws the AC in and flows to AC out to breaker box
  14. Shut system down in orderly fashion
  15. NEXT:
    1. I will configure the battery bank at foot of inverter (will add details soon) verify the bank is fully operational with monitoring and controls and connect to the DC in posts to the inverter.
 
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