10-KW* DIY Install - MPP Solar LV5048 - 2x Tesla Modules

[SolarBro]

Thank you all for the help with some technical questions I had for this install. I thought Id pay it forward and show & tell this setup.

24x 300w 72-cell Poly panels 7.5 kw, 10KW soon.
LV 5048 Inverter
2x tesla modules
Unistrut DIY Pole-Barn type rack.
Misc. Equipment and such.

Total build cost was 7500$. I got a ton of deals and the bulk was building the rack myself.

I know I will get some hate for cutting costs using unistrut but its sturdy and im happy with how everything turned out.

Plus much of the material was free or recycled on craigslist and its better to save it from the landfill.


My Grid panel far left, Critical load center and my Dump load panel below it. All my DC breakers are in the white din rail box.


Covered all the panels up, have my dump load contactor mounted and a window AC unit (wills advice) in my power shed. Red box is a fire box to store the tesla modules. Fireboy Automatic fire unit on the wall. Still have little things to fix...


My two tesla modules. 300 AMP fused and 125 amp circuit breaker per inverter. No BMS, only charge to 48.2 volts and discharge to 44V. I wish there was a plug n play affordable BMS solution.

There is several youtubers running these for 2 years plus with no issues so long as they undercharge them. I put them in this fire rated nox just incase they go boom, i might be ok.



My DIY unistrut Rack. Build like a pole barn with poles set in concrete 4 ft down. Feels solid with lag bolted down unistrut. Temp fence to keep the cows out.


Behind the rack. Stainless clips and zips to keep the wire clean. Weatherhead entrance to 2x MNPN6s, has DIN rail mounted surge suppressors (not seen)


My DC disconnects from the outside of the shed incase of emergency. Upsized just incase I need high amperage down the road.


This was really fun to build and install. Ive never done solar before this but i have some electrical experience and along with youtube, i was able to do this. Engineer 775s vids about gutters was key in my install.

If you have any question, just let me know. Thank you all for the help!

SolarBro.

 

[SKOTO]

Thank you all for the help with some technical questions I had for this install. I thought Id pay it forward and show & tell this setup.

24x 300w 72-cell Poly panels 7.5 kw, 10KW soon.
LV 5048 Inverter
2x tesla modules
Unistrut DIY Pole-Barn type rack.
Misc. Equipment and such.

Total build cost was 7500$. I got a ton of deals and the bulk was building the rack myself.

I know I will get some hate for cutting costs using unistrut but its sturdy and im happy with how everything turned out.

Plus much of the material was free or recycled on craigslist and its better to save it from the landfill.

View attachment 18755
My Grid panel far left, Critical load center and my Dump load panel below it. All my DC breakers are in the white din rail box.

View attachment 18758
Covered all the panels up, have my dump load contactor mounted and a window AC unit (wills advice) in my power shed. Red box is a fire box to store the tesla modules. Fireboy Automatic fire unit on the wall. Still have little things to fix...

View attachment 18759
My DIY unistrut Rack. Build like a pole barn with poles set in concrete 4 ft down. Feels solid with lag bolted down unistrut. Temp fence to keep the cows out.

View attachment 18761
Behind the rack. Stainless clips and zips to keep the wire clean. Weatherhead entrance to 2x MNPN6s, has DIN rail mounted surge suppressors (not seen)

View attachment 18762
My DC disconnects from the outside of the shed incase of emergency. Upsized just incase I need high amperage down the road.


This was really fun to build and install. Ive never done solar before this but i have some electrical experience and along with youtube, i was able to do this. Engineer 775s vids about gutters was key in my install.

If you have any question, just let me know. Thank you all for the help!

SolarBro.

Very impressive installation job there, bravo and keep it up

 

[SolarBro]

I fixed a my battery box by getting the 2" metal flex on it. Ill be adding a GFDI from @dougbert when that arrives from his old trace system.

 

[dougbert]

nice implementation

wish I had land..............

I am doing all of my stuff on a 40'x100' lot......long story
but I make do

 

[dougbert]

My two tesla modules. 300 AMP fused and 125 amp circuit breaker per inverter. No BMS, only charge to 48.2 volts and discharge to 44V. I wish there was a plug n play affordable BMS solution.

well I love the ESP32 tesla battery controller system (which uses the tesla BMS boards on the batteries), love the protection it provides
but it does come with a price as you saw in my build thread

 

[SolarBro]

well I love the ESP32 tesla battery controller system (which uses the tesla BMS boards on the batteries), love the protection it provides
but it does come with a price as you saw in my build thread

I saw a new tesla module BMS that is plug n play that is going to be released this november. It will have a screen and everything from overseas.

Hopefully it will fix this issue forever.

 

[SolarBro]

I have another update on my system.

Heres how I implemented a Dump Load On my MPP solar inverter using the dry contact port.

Not an electrician but here is some tips.

-Dry contact ports do not output any current or voltage. They only close a circuit. So incase your putting a voltmeter to read its voltage, there isnt any. Use the continuity function instead to see when the ports close.

I used a RIB 21CDC relay and a 120v coil/ 2 Pole contactor rated for 40amps.

These parts cost me about 40$.

The RIB has two wires for the dry contact, it is these wires that are connected to the inverter to engage the relay.

The RIB then will send 120v to one of the output wires to one side of the contactor. You will need to run a neutral wire from the panel to the other side of the contactor for this to work. (The RIB doesnt switch neutrals for you, only 120v)

This contactor then engages both l1 and l2 from my critcal loads panel to my dumpload panel where I have a water heater or air compressor circuit. This give me a way to store energy in other means.





The red light means the dump load is active. I suggest MPP solar users invest in a dump load as it is easy and inexpensive.

 

[SolarBro]

@dougbert

I got my GFDI installed today and also added a timer on my dump load circuit.





I think MPP solar should add gfdi protection to their inverters. Its in all charge controllers nowadays and they still dont have the feature.

 

[SolarBro]

I'll be adding an active balancer to my Tesla modules. I will update this build soon.

 

[Skysthelimit]

Wow! You have accomplished a lot for "not being an electrician". I wish I had 1/2 your knowledge so I could just make some decisions on what to build to power my barn/house that we're breaking ground on soon. We're off grid and it will all be on me to design and install the solar array and everything else. Anyway, I wanted to ask why you need a "dump"? I thought those were only needed in wind power set-up's, which, coincidentally, I am planning on implementing in my build too.

 

[SolarBro]

Wow! You have accomplished a lot for "not being an electrician". I wish I had 1/2 your knowledge so I could just make some decisions on what to build to power my barn/house that we're breaking ground on soon. We're off grid and it will all be on me to design and install the solar array and everything else. Anyway, I wanted to ask why you need a "dump"? I thought those were only needed in wind power set-up's, which, coincidentally, I am planning on implementing in my build too.

The dump load helps use the excess power created during the day. Its good to have and easy to setup on mpp solar units and the best part is the dump load can be anything. I just use a water heater as heating water is very power intensive and a nice luxury to have.

LMK if you have questions. You can PM me anytime.

 

[SolarBro]

I updated the tesla modules with active balancers. Thanks to @snoobler for the help.

This is where i started.


I took out the telsa BMS and it seems i have the older style modules. I cut the wires one by one and put the connector back into the board. The board itself has the cells labeled and makes it simple to wire.



I used solder tubes and shrink to wire the leads.





After 2 days of 2 amp balancing i got it here.



The tesla modules i feel are alot safer now. I will keep running them up to 48.2v down to 44v.

 

[the_uglydog]

WOW! That's excellent! I hope mine comes out as good. That's about it. the dog

 

[SolarBro]

Ill be updating this rig with another lv5048 and another battery balancer soon.

 

[SolarBro]

I got to update my system with another active balancer. These do very well with the modules. All cells are within .03 volts of each other. Feeling very safe over a non-managed battery.

I went on then to install a second lv 5048. It was very painless with the wiring trough. Also I decided not to use bus bars to distribute the power from the batterys, instead using a power distribution block rated for 440 amps. Its from galco industrys and was like 60$. A much better and smoother option than dealing with bus bars and lugs.


The PDB also helped me keep my DC and AC sides seperate in the wiring. Atleast trying my best to follow NEC.





I comissioned it running my full electric dryer and all my stove burners on, plus mini splits and lights on. It was pulling 9000 watts and didnt even break a sweat.

However my next upgrade might be two more modules and 12 more panels down the road. I have enough inverter to satisfy my daytime solar direct uses for now.

I hope it looks clean, as ive learned so much doing this. Thanks to @snoobler and others who gave me the tips to fix the issues i had.

 

[jasonhc73]

Excellent clean looking install.

I don't understand why everybody doesn't use Unistrut either. It's cheap, plentiful, and has thousands of optional attachments (well probably hundreds). It isn't exactly easy to cut though.

What voltage are you setup with your panels?
I had mine set with 3 panels with the potential to do 120+ volts when cold and that kind of scared me for cold weather. I'm doing 80 Volt strings now. I have 1 string on each inverter, each string is a 3Px2S for an 80 VOC 24 amp(max) string, on 8 AWG lines. 12 total panels for my off-grid setup.

 

[SolarBro]

Excellent clean looking install.

I don't understand why everybody doesn't use Unistrut either. It's cheap, plentiful, and has thousands of optional attachments (well probably hundreds). It isn't exactly easy to cut though.

What voltage are you setup with your panels?
I had mine set with 3 panels with the potential to do 120+ volts when cold and that kind of scared me for cold weather. I'm doing 80 Volt strings now. I have 1 string on each inverter, each string is a 3Px2S for an 80 VOC 24 amp(max) string, on 8 AWG lines. 12 total panels for my off-grid setup.

I like unistrut but it does have corrosion issues and its not the simpliest to bond panels together. I had to go to old school and run a 6 awg ground wire to every panel to bond things together. With iron ridge, i'd just have to bond the rails and not every panel.


My panels are 72 cell so I couldnt do 3 panels per string as it would run at the very tip of my charge controller. It currently runs at 80 volts with 2 per string and the run is about 220 ft away from the power shed. I have 12 strings of 2 panels, dual combiners putting each PV line at about 60 amps. If I added another 12 panels, id add another combiner with the spare conduit run I have to the array.

I ran 2 Gauge aluminum for the under ground and that saved me alot of money. You can use AL for DC circuits. I don't see alot of installers here saving money by using underground AL. My voltage drop was under 3%.

 

[jasonhc73]

Mine are 72 cell also. I do not have a long DC run like you, maybe 40 feet.

It "only" took me seven months to finally put the second set of six panels on the roof. I had them on the ground leaning against the wall.

All the stuff on the second set is ground water salt from my irrigation well.

Interesting and such a let down that even with plenty of sunshine, ground contact, and regular watering, the panels just refused to grow into 96 cell panels. ??

 

[SolarBro]

Mine are 72 cell also. I do not have a long DC run like you, maybe 40 feet.

It "only" took me seven months to finally put the second set of six panels on the roof. I had them on the ground leaning against the wall.

All the stuff on the second set is ground water salt from my irrigation well.

Interesting and such a let down that even with plenty of sunshine, ground contact, and regular watering, the panels just refused to grow into 96 cell panels. ??

Unistrut did save me alot of money. Id rather buy more batterys or panels than have to spend the extra on racking.

Id eventually like to add 12 more panels, i got them for 60$ each used for 300 watts. I don't think i can find a better deal than used commercial poly panels.

5 years from now, who knows how cheap those 96 cell panels will get. Same with batterys, lithium is cheap enough that solar makes alot of sense.

 

[SolarBro]

Ive added the rest of the panels and now have a full 10KW of solar on my ground mount.