My new 5kva Victron build

[Willemt]

So at last my thread on my build…

Some background… My longing for solar is not a recent story… I almost bought a solar franchise back in 2012, but that didn’t happen as I got another job offer at the same time…

Then in 2016 my longing for cheap water and a green garden won the vote for the available funds and I drilled a borehole and installed pumps etc…

Then some time in 2021 I bought some 5kva multis… sold one of the three and planned to use the other 2…
Just as I started I got a new job in Swellendam and since the multi is not nrs compliant I sold them and replaced them with one multi II, also 5kva…

So moved to Swellendam and started to pick up the pieces of the projects I had to pack away… and also gave some projects away…
Obviously the first project to be unpacked in the solar…

I wanted to build some DIY batteries and got 2 JBD BMSes from TTT… Just as I was about to request the invoice for the 34 cells another friend pointed me towards an add for two basically new BSL 6.4s, which I got at an absolute steal… Same price of building DIY… less than 'n year old and used extremely lightly…
So I ran to Melkbos and picked them up. BMSes both shows 100% health, and I reckon only 30 - 40% max was used on cycling…

So where is my system at now:
I am renting in Swellendam at the moment so decided to not fix everything to the wall…
I thus built a stainless frame with wood boards on and fixed everything to that…
The 5kva Multi II, the 250/100 mppt, cerbo, DB, two fuse holders and the batteries will get a seperate stand.

I don’t have permission yet from the landlord to put solar on the roof, but we’ll sort that out in time. If I don’t get permission I’ll fit the panels on a frame on the empty erf next to me… So we’ll see what happens on the PV side in the next week or so.

For starters I’ve started to wire up the DC side of things. Ordered all my correct cables from victron and used some 50mm^2 cable which I have plenty off for the DC cables. Just need to put some red and black heat shrink on them. For now just used blue for + as there is no red or black heatshrink in sellendam.
Got them crimped today at the workshop and connected them up.

The plan with the DC buss is to use the two fuse holders, one as - and the other as +… Will fit 'n nice big buss bar on their top and then fuse the batt, inv, and mppt all coming in from the bottom. For now just linked the inverter straight through on 160A fuses.

So yeah that’s where I’m standing… The batt comms with the cerbo seems ok… although it’s not picking up correctly… It sees them as LG batteries. But the comms are generally good between the batts and cerbo, it picks up the correct sum of capacities in terms of charging and discharging limits so generally happy about that.

Need to plug in the MK3 - usb cable over the weekend and set the inverter up from the laptop…
Then next week I need to get my RS485 to usb cable crimped as they don’t come with a RJ45 connector on the one side but just 4 bare wires… If that done then I can fit the Carlo Gavazzi ET112 into my main DB and also link that up to the Cerbo.

Plan is to split my main DB into essentials and non essentials, and then have the ET112 just after my prepaid box. That way I can feed back to my stove and geyser once my PV is up… Also got a CT clamp for the Multi, but believe it’s nicer to have a seperate EM connected to the cerbo for a better representation in VRM…

Anyway that’s about it for now, will update as I go along and as I might need some help setting up the victron gear…

[Willemt]

So got down to programming the Multi last night.
Decided while i’m busy to update the firmware aswell…
there was a newer firmware update out so flashed that and then went on to program the multi according to the BSL manual…
The thing I did note was that on the battery side there was some minor differences between the 5.1 and the 6.4 kwh batteries from bsl’s side.
I cannot find a manual for the 6.4…
What I now need to get done next is to see if it is some how possible to update the firmware on the BSL BMS.
The one bms doesn’t give the correct parameters through to the cerbo, but if I use the other one as the master and the first one as a slave then it does actually give the correct parameters and summation of the capacities of the two through.

I’m very keen on adding a 3rd 6.4 to the pack… But will have to wait a while for funds.

I also just found out on Friday that I can’t get any normal red or black wire in Swellendam… So need to find some somewhere so that I can start wiring the AC DB…

For the AC DB I’m planning on just getting the smallest double row DB I can, and then to put the ET112 and the two main breakers in there, and add some lights to show when grid and inverter output has power.
Again not having the box I want might push me to just use another small one that I do have…

I must still get use to not being able to get what ever I what here in the platteland… quite a stark contrast to living in Durbanville where I was 20 minutes form anything…

[Whatyamacallit]

@Willemt

I can’t get any normal red or black wire in Swellendam

Don’t worry even in JHB it can sometimes be a pain to find the right stuff. Cant you just use a different color and then get red and black heat shrink for the ends?

[Willemt]

Well for the DC cables I’m using some 50mm^2 cable that I have plenty off… 1000V rating on isolation, but in yellow and green. On that I’m more than happy to do the heatshrink ends for red and black, but on the AC wiring in the DBs I’m not making any compromises… Stuff needs to be 100% correct and according to regulations…
So will get some wire during the week. But no, they don’t have any colour available…

[Phil.g00]

Wrap it with coloured insulation tape.

[plonkster]

I’m not sure if you meant that as a joke… but I heard that apparently that is allowed in some codes.

When I moved into this house, I had a black wire wrapped in red tape, and a black wire wrapped in yellow/green tape in the DB. Guy probably only had black wire that day… but he did have tape! I was told this is apparently fine, even if my OCD triggers.

It has been remedied in the mean time. For what they charged the previous owner to CoC the place, they honestly could have done it earlier.

[Louisvdw]

My DB also had taped cables to get the color right. I guess red and black insulation tape is much cheaper than cables?

[Willemt]

I hope the tape is a joke but I would rather die than taping wire…
Like I mentioned, for thick DC wires I feel that heat shrink is ok, but I generally stay as far away form insulation tape as possible. It’s a mess afterwards and utterly “slordig”. But the things people do, my ex neighbor in durbanville after he bought his house found the whole ceiling full of twin flex going to all the lights etc… with an inspection cert…

[Willemt]

Any one have any info regarding the possibility to flash new firmware on the BSL BMSes?

[Willemt]

So making some slow progress.
Need to find some panels… before all stock in SA gets sold out… Seems lots of places are running low on stock after this last stint of loadshedding…
So got a small dc dist board wired up… Realised now that I should have just gone with 40A breakers and 6mm^2 ac house wire… Running the 10mm^2 now, and already a lot more difficult to work with.
Would like to add quite a few more things in the AC board… But for now have the bare essentials…
I had the din rail double lights, and am quite liking how they turned out… Using the top light for incoming, and bottom one for outgoing… Left breaker for incoming post EM, right breaker for AC out… with EL…

Got the EM wired up as well… So I’m ready and set to connect up with the house db…
Just waiting for the munic to install a split prepaid meter, then I can use the location of the old one with the conduits in the wall as an easy entrance to the DB…
Just waiting for approval from the landlord…
Thinking that I’m going to buy panels in any way… if he doesn’t want them on the roof then I’ll make stands for them and bolt them on some where…