Looking for input on my 24v Victron based layout I'm planning

[fisherman]

Good Morning,

I'm planning on adding solar to my cottage which is completely off grid. I'm trying to build it so I can scale out additional panels and batteries as needed. I really like the Victron line so I'm planning the below layout. I've done a power audit and will eventually need more batteries, but I'm hoping I'm on the right track. I'm looking for general feedback and also had a few questions.

1. What devices should I be grounding to earth?
2. If I'm using a Honda floating neutral generator to supplement the inverter/charger, is the bonded neutral/ground on the panel sufficient/correct?
3. Are there any additional fuses or components I should consider with this layout; aside from more batteries?
4. Is there a UL/CSA approved solar disconnect/combiner box? If not what are some good brands to consider? I'd need something that can handle 140v.

Thanks in advance.

 

[sunshine_eggo]

1. I'm not qualified to comment on grounding. Check with your local/national code requirements.
2. It shouldn't be an issue. Important to consult:

MultiPlus Generator FAQ [Victron Energy]

www.victronenergy.com

3. See comments below.
4. If UL is a concern, have you confirmed that the Victron hardware is UL listed? Most aren't. Midnite Solar makes listed MNPV combiner boxes with relatively inexpensive 150VDC breakers.

3S on a 150/100 means the panels need to be Voc < 40V.

Fuses are not needed for 2P arrays. When you go to 3P, you need OCP.

150/100 Victron is overkill

3000W/24V/.85 = 147A draw from batteries.

4awg battery to lynx and lynx to MP are inadequate. I would use 2/0.

60A Inline fuse is not adequate. 60A Inline fuse should be before the cut off switch and a class T 200A fuse.

The 80A fuse to the inverter is not needed.

Add Cerbo GX for monitoring and logging.

 

[740GLE]

I’m sold on Victron as a company, I just can’t see the benefit the Lynx units adds for the cost, looks like it’s fancy bus bars with logging and possible breaker?

Almost looks like a smart shunt and some bus bars would cover quite a bit of needs and save quite a bit.

 

[fisherman]

3S on a 150/100 means the panels need to be Voc < 40V.

150/100 Victron is overkill

Thanks for your feedback! I used an online calculator to arrive at the 140V based on each panel having 39Voc. https://www.explorist.life/solar-charge-controller-calculator/

Should I consider a different wiring setup or SCC?

3000W/24V/.85 = 147A draw from batteries.
4awg battery to lynx and lynx to MP are inadequate. I would use 2/0.
60A Inline fuse is not adequate. 60A Inline fuse should be before the cut off switch and a class T 200A fuse.

Ok I will adjust for that thank you!

So the 200A fuse gets placed as close to the batteries as possible?

Add Cerbo GX for monitoring and logging.

That sound good. More$ but I think that would make the most of this investment.

 

[sunshine_eggo]

Thanks for your feedback! I used an online calculator to arrive at the 140V based on each panel having 39Voc. https://www.explorist.life/solar-charge-controller-calculator/

Should I consider a different wiring setup or SCC?

No. 3S 39Voc is fine

So the 200A fuse gets placed as close to the batteries as possible?

whenever practical, fuses are best placed as close as possible to the source.

That sound good. More$ but I think that would make the most of this investment.

It's freaking magic. I have the older color control GX (CCGX) that provides the same integration function but with fewer connectivity options. It was the last thing I implemented, and it should have been the first. 6 month detailed data logging, 5 year summary data records and I can remotely monitor and configure essentially everything.

 

[Hravn]

Since the Victorian shunt has a fuse holder, as does the lynx distributer, I would think the 60 amp fuse is doubly redundant, as well as too small for the potential load of 3000/24 + 20% or so, so call it 150 amps for the shunt fuse. And 1/0 or 2/0 wire.

my in-progress set up is similar but with a 24-12 transformer and a 12 volt fuse block for lights and usb stuff, and using a eg4 24 volt battery.

 

[sunshine_eggo]

Since the Victorian shunt has a fuse holder, as does the lynx distributer, I would think the 60 amp fuse is doubly redundant

Nope. The fuses in the Lynx are not Class T. For LFP, you need the high AIC rating of Class T fuses.

 

[Hravn]

Nope. The fuses in the Lynx are not Class T. For LFP, you need the high AIC rating of Class T fuses.

is a class t fuse not usable in the lynx shunt ?

 

[jwelter99]

Good Morning,

I'm planning on adding solar to my cottage which is completely off grid. I'm trying to build it so I can scale out additional panels and batteries as needed. I really like the Victron line so I'm planning the below layout. I've done a power audit and will eventually need more batteries, but I'm hoping I'm on the right track. I'm looking for general feedback and also had a few questions.

1. What devices should I be grounding to earth?
2. If I'm using a Honda floating neutral generator to supplement the inverter/charger, is the bonded neutral/ground on the panel sufficient/correct?
3. Are there any additional fuses or components I should consider with this layout; aside from more batteries?
4. Is there a UL/CSA approved solar disconnect/combiner box? If not what are some good brands to consider? I'd need something that can handle 140v.

Thanks in advance.

View attachment 94885

4 gauge to the Multiplus is undersized. Likely should be 1/0 but read the Victron manual as they will have lenght/gauge called out. Follow it.

The Lynx Shunt has a ANL fuse holder which will work but the AIC rating needs to be your concern. Buy good fuses and not no-name shit on Amazon -- it matters both when they blow and how they blow. You want it to blow at current it's rated and to blow cleanly open. Cheap fuses may not do this and cause big issues.

Class T would be better but if you are set on the Lynx Shunt I'd just got the ANL and skip the T -- back to back fuses doesn't make sense.

 

[The Dish Doc]

No. 3S 39Voc is fine



whenever practical, fuses are best placed as close as possible to the source.



It's freaking magic. I have the older color control GX (CCGX) that provides the same integration function but with fewer connectivity options. It was the last thing I implemented, and it should have been the first. 6 month detailed data logging, 5 year summary data records and I can remotely monitor and configure essentially everything.

Will this unit interface with any solar system? Renogys app leaves much to be desire.

 

[sunshine_eggo]

No. Victron hardware is victron specific. For more advanced integrated grid-tie systems, victron GX can interface with Fronius and other PV inverters as part of an integrated Energy Storage System (ESS) to allow for opportunistic load shifting for peak shaving.

 

[fisherman]

4 gauge to the Multiplus is undersized. Likely should be 1/0 but read the Victron manual as they will have lenght/gauge called out. Follow it.

Ok thanks I'll have a read of the manual.

Class T would be better but if you are set on the Lynx Shunt I'd just got the ANL

Sounds good. I'd like to go with the Lynx shunt for my setup.

 

[sunshine_eggo]

Ok thanks I'll have a read of the manual.


Sounds good. I'd like to go with the Lynx shunt for my setup.

LFP pretty much demands Class T. Not all fuses are the same. Large currents can overwhelm a fuse. LFP can deliver massive current due to their low resistance, and an ANL fuse may not be able to stop the current.

IMHO, spend the money on a quality Class T fuse and holder.

https://www.amazon.com/gp/product/B00153CXJC

 

[fisherman]

IMHO, spend the money on a quality Class T fuse and holder.

I will do that seeing it offers better protection. Thank you.

 

[Lilikoi_Heavy_Industries]

Is this a new system? Why not 48V? You only have 40amps of solar to handle on a 48v system, which allows you to buy a smaller charge controller. As it is, you'll need an 80amp (which is no big deal, just know you're spending more because you designed for 24v). Same for your wiring sizes, they would be much closer to sufficient if you were on 48V.

You don't need to buy a CerboGX if you can find a RaspberryPi, and a couple victron cables ($80 inverter adapter, $30 BMV712 adapter, probably $30 SCC adapter?) to buy since the RaspberryPi can run VenusOS and talk to VRM portal instead of a CerboGX. Might save a few dollars, but at least it's easy to buy a CerboGX. Very hard to find available RaspberryPi right now. The VRM portal and the data aggregation available with Victron is amazing and you do need this component to use it (CerboGx or Pi running VenusOS).

I agree that you should be using some bus bars and a smartshunt or BMV712. All the lynx stuff is overpriced and not even necessarily correct for your setup. Read the inverter manuals, they state the length and gauge of the inverter wires. It also states the size of the breaker.

This is the first drawing I've ever seen "MC4 fuses", and awarding points for "creativity" is probably a bad thing here. I'd typically use a midnight 3 string combiner box here, but I've been told you can do two strings "to code" without a combiner box (I assume that means Y cable, and that "to code" means the 1987 electric code...). I like to be able to shut the strings off at the breakers though. The PV shutoff switches with the rotating switch along with a Y cable to combine strings could be good for that too.

Edited to add: I'm a happy user of Multiplus II 48/3000/35, Victron is great so far and I was happy to see a thread on it! I use both eu2200 and a firman dualfuel 3200watt inverter generator with it, the MultiPlusII can do anything with a tiny generator, powerassist is really cool. I wish I had a victron solar charge controller like you will because the VRM portal charts won't include solar properly (or will seem strangely implemented) unless you buy their equipment.

 

[sunshine_eggo]

You don't need to buy a CerboGX if you can find a RaspberryPi, and a couple victron cables ($80 inverter adapter, $30 BMV712 adapter, probably $30 SCC adapter?) to buy since the RaspberryPi can run VenusOS and talk to VRM portal instead of a CerboGX. Might save a few dollars, but at least it's easy to buy a CerboGX. Very hard to find available RaspberryPi right now. The VRM portal and the data aggregation available with Victron is amazing and you do need this component to use it (CerboGx or Pi running VenusOS).

Really "pro" recommendation there... "Get this instead, but you can't find them."

VE.Direct to USB and MK3 to USB adapters start to add up. VE.direct cables are cheap.

I agree that you should be using some bus bars and a smartshunt or BMV712. All the lynx stuff is overpriced and not even necessarily correct for your setup. Read the inverter manuals, they state the length and gauge of the inverter wires. It also states the size of the breaker.

Late to the party.

This is the first drawing I've ever seen "MC4 fuses", and awarding points for "creativity" is probably a bad thing here.

You don't get out much?

I'd typically use a midnight 3 string combiner box here

MNPV mentioned already.

but I've been told you can do two strings "to code" without a combiner box (I assume that means Y cable, and that "to code" means the 1987 electric code...).

Clearly you don't know the code. Please review NFPA NEC 2020 690.9(A)(1) and (A)(2). Articles on changes for 2023 do not indicate this portion of the code will change for 2023.

 

[Lilikoi_Heavy_Industries]

Really "pro" recommendation there... "Get this instead, but you can't find them."

Hey there little buddy, wasn't even talking to you. Go ahead and eat your cheerios and scoot along.

 

[fisherman]

Layout has been updated based on feedback. Thanks you. If anyone else has any input on this it would be appreciated!