I’m preparing to build a solar PV for my house. (off-grid due to unstable power here)
48V with 2 inverters in parallel
for now it will be one charge controller with 12 PV panels
about 30kW on battery storage
I was searching for a decent bussbar and fuse holder system and I’ve come down to using ANL fuses (due to availability here) and made my own busbar/fuse holder combo.
Coating? Well, only recommendations and articles that copper bus bars need a coating are coming from … surprise… Coating Manufacturers
Generally, copper will coat itself with a patina to prevent any further corrosion and bellow the connection points it should be save - or did you ever coat any copper wire before putting it into a breaker or something where it is gonna sit for 25 years+
I didn’t put anything onto my bars until now. But ofc. It’s not like my system will be unattended for several months, I will closely watch this and eventually check connections once in a while, etc.
Very nice, i done something similar but used Class T fuses, i only coated the joints (as i have copper bolts on copper busbar i didn’t have to but…), i had my busbar made for me so i could connect all the batteries + and fuses on one continues length. (i couldn’t bend 25x10mm copper easily)
This is the stuff i use to protect the joints.
Do you plan on switching the system off should you ever need to change a fuse? A 48V busbar inbetween two grounded busbars sounds like fun to work on while its powered on.
yes, the system will be off when changing fuses and/or checking overall state. I’m very used to power outages. turning all OFF is not a big issue.
the battery switch will be on the side of the bussbar/fuse
I can change the copper bar order and have the fuses out of the way but I know I could try to do it while its HOT but its to risky…
I don’t want to mess around with 30kW of batteries. they will chew trough the copper bar easy.
if/when I have to add more batteries I’ll probably have to extend positive busbar to have decent spacing for the sets of terminals (going into the battery Switches).
I still have to take it apart to clean and do a “safety” coating. I have the chemicals for years and I’m pretty sure it will help when the time comes to change a fuse (or add a second PV array)
I’m not sure on what coating to use. I have a cold tin solution and I can get my hands on a silver coating solution for cheap.
The silver one looks amazing (I’ve used up all my stock) but the tin might be enough. It’s just a detail since I have the fuses on the busbar and if/when I have to replace a fuse in a slight hurry… I don’t think I’ll do a good cleaning job on any corrosion there …
been working on my system and reading all the details in the manuals of all my parts and has to make a change to my busbar.
also made it a little more expansion proof if/when I have to add to the system.
I’ve also added a silver coating to the bars since I may have a little corrosion due to humidity… better safe than sorry since the coating is cheap but pretty toxic and kinda labour intensive… (but I’ll show the results!)
not shown in here are the protection plastics that I still need to cut/modify but now my busbar has fuses, the load side contactor and the battery isolator switch (to make it a little bit more compact)
also changed the bars. now its more accessible for connections and change fuses.
in the begining I’ll have a solar charge controller and 2 inverters. soon(ish) ill want to add a second charge controller and double on the batteries (money and space issues for now… I have to pretty much remake all my electrical panels while changing to solar)
any inputs or ideas are welcome. better to correct any issue now than later on
I’m finally installing my system! I’ve been testing everything out. Still getting up to work on the solar panels structures to get the PV coming up.
I’m having a few issues with the grid power input for charging… My electrical grid is very “dim” and when I set the input power limits they kinda get ignored or I just have a wrong measurement on my system.
I’ve got:
123smart BMS on the battery
Cerbo s GX
2x multiplus II 48/5000/70 in parallel
One external CT (measuring the output power) on the master inverter.
1 smart solar mppt still waiting to have it’s time
The bms is talking back to the cerbo.
The inverters are responding to most of the system configuration. Just not the input current/power.
I’m gonna find some time to make a block diagram of what I have to further explain my doubts.
I still have to make some adjustments and learn some configurations here and there.
Today the power assist was tripping my breakers when some heavier loads were coming up… And the inverters made some noise and I got a warning saying overload.
I’ve moved some loads of the system while I get jt recharged since I just did my first battery cycle to know the total storage and hopefully configure the meters and battery health.
Turns out the external CT is not needed on my setup. I’ve read on the manual “parallel something something, external CT” but … I’ve should have read better: I only need an external CT for parallel grid connection (which I don’t want to ever do here)
now I have the power measurements all just about right. the power assist and current limits seem to work perfectly.
I took a long time to get to building the system due to my father sickness.
we had a lightning strike real close by that took out a couple of electronics around the house. I had do re-design the ground rods on my house and add surge protection pretty much everywhere: even on my UPS output and battery (that I’m using for automation, aux supply, network and cerbo power).
since I’ve lost half my network, I’m trying to have all my access points running on POE and if its stable enough I’ll try to use some equipment on wireless (which I kinda try to avoid…)
I also had a miss-hap on a finger with a belt sander (still under recovery/correction) and a couple of days ago I got a fire department haircut due to another miss-hap with the angle grinder. I’m being a danger to myself. I’m kinda overworked and have other concerns while I’m trying to get all this done. I’m being a little bit mindful about myself now. maybe its the stitches.
I’m going to be working on the solar array structure. I need to weld quite some iron tubing. I’m rusty on welding, my finger is still not good but I’m using the power output of the inverters and it is so very stable!
I can’t wait to have the array going. after that I’ll re-configure the system to “never” use the grid/genset unless is really needed and I still have to have a few fallbacks if I loose the BMS coms or a few other details.
a few locked bypass controls if all batteries go out and I need to re-power the system from “any available” power source.
the only “issue” I seem to have here is the grid/shore power input current limit that seems to ignore the settings. I had to limit the charging current on the inverters configuration to avoid overloading my limited 3.45kW grid connection. I’ll try further testing now that all the power metering seem to be correct.
I’ll also need to read on ESS assistants and functions. they may come in handy
p.s.: I may have a almost new victron CT available for sale. it has about 36H of work on its back haha kidding, might use it somewhere else
new issues arise! expected them before and I’m on the way of sorting them out.
when I’m charging up from the grid I have a heavy drop in voltage. from the 230V nominal I get 202V with a 2000 to 3000W load.
I’m hoovering on buying another charger/inverter and use it just as a charger from the grid input when I get the cloudy days.
I’ve been trying to find how will it show on VRM to have another inverter as a AC charger from the grid?
will I have any way to activate it remotely like I have my inverters now?
this new inverter will have noting on its AC output and I only want its DC output to charge/power the system, independent from the AC voltage instability
I have a work around with one of the relay outputs on the cerbo if there’s no other way to control the thing.
I have another reason to get another inverter… If I ever have any kind of problem with the inverters there’s a lower chance that the charger inverter also fails at the same time so I’ll be able to swap one and have some power while I sort the problems out.
hopefully I’ll never get any weird problems but having half a backup plan lets me sleep better.
