EG4 6500 EX48 (just a single unit)

[anomaly_a]

Hey all,

Noob here (kind of)! I've seen several others ask this but didn't seem to see a solid answer. I pretty much want to do the exact setup in this video

except downsized to 1 EG4 6500 EX48 and smaller battery bank.

Looking at the plans and watching the video it seems pretty straight forward what adjustments are needed but I just wanted to do quick check.

So starting with the components listed on the 48V Offgrid Page from what I can tell I need this:

• EG4 6500EX All-in-one Solar Power System (x1)
• 2/0 AWG Inverter Cables
• 200-300A T-Class Fuse (1x) (the one in the post is out of stock so I was thinking one of these instead)
• 300A Busbars to connect your all-in-one systems together (not needed in 1x system setup)
• 4/0 Cables for Battery to Busbar Connection (also not needed, instead use 2/0 AWG to above in line fuse then to the AIO)
• PV DC Isolator (1x)
• Hardiboard (x1)

And everything else exactly the same (except reduced to 1 of everything that connects to the AIO). I am planning on starting with a single EG4 battery in the same rack used in the video but if that's not enough I can toss a couple more in there.

So the main difference being that since there are not 2 battery banks, and only 1 inverter the busbar is not needed and as a result of not having that 300A busbar there is no need for the 4/0 cables. Just 2/0 all the way through to the battery bank.

I can't seem to find the zero load draw of the EG4 6500 EX48 (I'm sure its on the forum somewhere but it doesn't seem to be in the manual) if anyone knows it.

Assuming that is all correct great! But the last question is that Will mentions in the video right about at 3:59 that SignatureSolar recommends putting this UL listed breaker instead. So if I wanted to go with this it makes sense that I would replace the 200A fuse and just toss this in there instead.

If anyone is interested I am setting up a small building on my property. I bought a ton of very cheap used solar panels (250 watt Canadian Solar) that I hope to fully off grid power. It will mainly run a bunch of LED lights and a 1 ton mini split heat pump (115v, ~800W) and have some AC outlets.

Thanks in advance guys.

 

[John Frum]

You will only have 120VAC not 120/240VAC.
Is that ok for your use case?

 

[anomaly_a]

You will only have 120VAC not 120/240VAC.
Is that ok for your use case?

Yeah, for now all I will be using is 120v. I figure this setup is nice because if at some point I decide I want 240v, I can toss on the rest of the describe components and bump it up. But as a mentioned just some lights and an AC. Maybe a laptop or charge a cell phone.

I realize I could probably go with a smaller inverter but I could foresee using some higher watt (120v) appliances like a pressure washer with it and figured a little extra max sustained current wouldn't hurt.

 

[John Frum]

6500 ac watts / .85 conversion factor / 48 volts low cutoff = 159.31372549 service amps
159.31372549 service amps / .8 fuse headroom = 199.142156863 fault amps.

I suggest you start with 2 batteries.

That ANL fuse is only rated for 32 volts.
This MRBF fuse is rated for 60 volts.

DC-FA-300, 300 Amp MRBF Fuse Kit | DonRowe.com

The DC-FA-300 us an easy, weatherproof and economical circuit protection for tight space constraints that offers 300 amps of over-current protection ensuring safe operation of your inverter.

www.donrowe.com

 

[John Frum]

What awg wire will you use to connect each battery to the rack busbars?

 

[anomaly_a]

6500 ac watts / .85 conversion factor / 48 volts low cutoff = 159.31372549 service amps
159.31372549 service amps / .8 fuse headroom = 199.142156863 fault amps.

I suggest you start with 2 batteries.

That ANL fuse is only rated for 32 volts.
This MRBF fuse rated for 60 volts.

DC-FA-300, 300 Amp MRBF Fuse Kit | DonRowe.com

The DC-FA-300 us an easy, weatherproof and economical circuit protection for tight space constraints that offers 300 amps of over-current protection ensuring safe operation of your inverter.

www.donrowe.com

And you'd do a fuse instead of the 60A 200V switch? I assume if you pop that fuse it's dead vs the switch you just have to switch back on again.

What awg wire will you use to connect each battery to the rack busbars?

That's good point, since I had originally planned a single battery I figured that could wait but since I'd already have a lot of extra feet of 2/0 I assume that would be plenty if not overkill.

 

[John Frum]

And you'd do a fuse instead of the 60A 200V switch? I assume if you pop that fuse it's dead vs the switch you just have to switch back on again.

I prefer fuses unless a means of disconnect is required.
Since each battery has a means of disconnect none is required for the AIO.
It should be a very rare occurrence that you blow a fuse.
A spare is a good idea though.

That's good point, since I had originally planned a single battery I figured that could wait but since I'd already have a lot of extra feet of 2/0 I assume that would be plenty if not overkill.

I fear you won't be able to get 2/0 lugs onto the battery terminals.

 

[anomaly_a]

I fear you won't be able to get 2/0 lugs onto the battery terminals.

Now that you mention it. I took a few minutes to watch the Will's battery build video for this rack and these batteries. He most certainly is not using 2/0 AWG between the batteries. Looks significantly thinner than a 2/0 (maybe half as thick). I just double checked and the listing for the battery says it comes with the cables for connecting the batteries to the rack.

 

[BajaOffGrid]

Thanks Anomaly, I am building the same system as you, just with a few more batteries.

Yes I thought the cables for battery to bus bar came with the batteries. Can anyone double confirm?

 

[SignatureSolarJames]

Thanks Anomaly, I am building the same system as you, just with a few more batteries.

Yes I thought the cables for battery to bus bar came with the batteries. Can anyone double confirm?

yes, cables from packs to bus bar included, inverter cables sold separately.

 

[John Frum]

yes, cables from packs to bus bar included, inverter cables sold separately.

What awg and insulation rating?

 

[John Frum]

.

 

[SignatureSolarJames]

5awg, 200C silicone, M6 terminal for 100A over 12 inches

 

[anomaly_a]

Awesome, thanks guys. I think I have just about ordered everything at this point. Now just waiting for the inverter to come back in stock. Looks like I missed this round and will be getting one from the next shipment unfortunately. Don't let the message on the Signature Solar site confuse you, if you haven't ordered already then you wont be getting one from their early Oct batch. I was told another batch is due at the end of Oct.

 

[anomaly_a]

Can anyone confirm that there is no need for the 4/0 AWG cables from the battery bank to the fuse? I am a little unclear as to whether this is what was used in the video because there was another battery off to the side or if it was because his system would need to be able to send power to both inverters simultaneously, thus requiring higher gauge right up to the bus where the power would then be halved and distributed to the 2 inverters.

I would like to have the ability to scale my system to 2 inverters down the line if needed so if I need 4/0 for a few feet from the battery bank to the fuse for now, it would be the same work and almost the same cost so I'd go ahead and do that.

 

[John Frum]

Can anyone confirm that there is no need for the 4/0 AWG cables from the battery bank to the fuse? I am a little unclear as to whether this is what was used in the video because there was another battery off to the side or if it was because his system would need to be able to send power to both inverters simultaneously, thus requiring higher gauge right up to the bus where the power would then be halved and distributed to the 2 inverters.

I would like to have the ability to scale my system to 2 inverters down the line if needed so if I need 4/0 for a few feet from the battery bank to the fuse for now, it would be the same work and almost the same cost so I'd go ahead and do that.

It all depends on the topology.
How many batteries will you have?
I suggest you get the rack with built in busbars and connect all circuits to the rack busbars.
Each inverter and each battery will have its own circuit.

The batteries get 5 awg as described above.
The batteries have their own over-current protection and means of disconnect.

The inverters draw more than each battery can supply so they get bigger cables.
2/0 awg is fine and a 300 amp MRBF fuse is fine with 2/0 awg.
The MRBF fuse carriers are connected directly to the rack positive busbar and Bo's yer uncle.

 

[John Frum]

Just for clarity... by the numbers you could go as low as 2 awg with a 200 amp fuse per inverter circuit.
1/0 awg with a 250 amp fuse is better.
2/0 awg with a 300 amp fuse is mo better.

 

[anomaly_a]

It all depends on the topology.
How many batteries will you have?
I suggest you get the rack with built in busbars and connect all circuits to the rack busbars.
Each inverter and each battery will have its own circuit.

The batteries get 5 awg as described above.
The batteries have their own over-current protection and means of disconnect.

The inverters draw more than each battery can supply so they get bigger cables.
2/0 awg is fine and a 300 amp MRBF fuse is fine with 2/0 awg.
The MRBF fuse carriers are connected directly to the rack positive busbar and Bo's yer uncle.

Right now I went with your suggestion of 2 bats, but got the rack with 6 slots. I suppose if I ever add more I could always up the gauge of the wire pretty easily. Thanks again for all the suggestions.

 

[John Frum]

Right now I went with your suggestion of 2 bats, but got the rack with 6 slots. I suppose if I ever add more I could always up the gauge of the wire pretty easily. Thanks again for all the suggestions.

2 batteries is for a single inverter.
Now that you will be doing 2 inverters you should have 4 batteries.
Since each battery and inverter is on its own circuit you won't need to upgrade any wires as they will be correctly sized from the beginning.

 

[anomaly_a]

2 batteries is for a single inverter.
Now that you will be doing 2 inverters you should have 4 batteries.
Since each battery and inverter is on its own circuit you won't need to upgrade any wires as they will be correctly sized from the beginning.

I'm still going with just 1 inverter for now. Just building everything with room to expand, wanted to make sure I shouldn't just go with 4/0 from the start in case I do upgrade. So just 1 inverter, 2 bats in a rack is the plan. 2/0 all the way from the inverter to the bats with a fuse in the middle.