Please cast your eyes over this setup

[terry82517]

Please could you comment on this set up plan? Does it look safe? Anything you would change?
My battery is a 280ah lifepo4 from xuba.

 

[Craig]

Looks good what about a BMS

 

[terry82517]

Looks good what about a BMS

Thanks Craig. Do all the wire sizes look correct?

Im going to use the 120amp bms that Will recommends . Dykb I think it’s called.

 

[terry82517]

Anyone else do anything different here?

 

[tictag]

What is the specification of the cable you are using? I am going to assume stranded automotive cable i.e. stranded copper, 70oC PVC insulation.

Some considerations:

1. Circuit breakers are an unnecessary expense for this project, cheaper and simpler to use fuses.
2. I'm not sure what "DP" is in your diagram, but I would recommend adding DC isolation switches to both the PV and Battery circuit. You will want to isolate all power sources to work on your system.
3. Consider using +ive and -ive busbars rather than direct connections to your battery
4. Your application seems to be for a caravan or RV, consider using a purpose-made AC & DC power distribution unit
5. If you don't use a purpose-made PDU, consider the AC side of your design i.e. equipment & earth bonding, MCB(s), RCD etc.
6. The cable leading from the +ive terminal to your 200A CB is not protected, consider using a terminal fuse.
7. How long is your PV cable run? Consider staying within a maximum of 3% voltage drop.
8. You don't have fuse ratings depicted, ensure each is lower than the ampacity rating of the cable used for the respective circuit.
9. Consider adding a shunt-based energy monitor

You have not provided sufficient information to comment on all cable sizes but for those listed, cable sizes looks good. To comment further, please state continuous load of components.

I cannot comment on how the overall system design would meet your requirements because I don't know what they are, but assuming that you have sized your battery to provide 3 days' autonomy this would indicate a circa 1,120Wh daily energy consumption with 1,280Wh being generated from your PV array in Summer, which seems to be a good design, though you would need to at least triple your array, or augment generation with a genset or wind turbine, for continued off-grid use during Winter.

Edit: Corrected typo

 

[terry82517]

Hi @tictag Thankyou for your reply.

wire is stranded copper.

1.on your recommendation I have swapped breakers for fuses.

2. changed this to a isolation switch and added one after the battery too.

3.have added bus bars to plan.

4. Yes it’s for a camper van but I don’t understand this sorry.

5. don’t know what this is ether.

6. Added fuse to plan

7. included pv wire length. I believe this is in range.

8. have added ratings to plan.

9. my bms has a shunt Thing in it where I can use a app to monitor battery use.

Panel size is on the small size yes but I’m not planing on running the battery down very much As most loads will only be on for a few hours of a evening, only the fridge will be on all the time.

please see new plan picture . Thanks again

 

[John Frum]

1. Your application seems to be for a caravan or RV, consider using a purpose-made AC & DC power distribution unit

What a great idea.
I just checked amazon and at least wfco and progressive dynamics combo panels are available.
I have not seen anyone do this.
If anyone has done this please reply.

 

[PHoganDive]

FYI, fuses connected to the battery should be located as close to the battery as possible, their main function is to protect the WIRE going to the device(s) it powers. If you wish a fuse to protect the device, locate it at the device end of the wire.