Fuses and wire gauge [Diagram] - six LVX 6048-WP in parallel and three 48v 280Ah packs

[MartyByrde]

Hi,

I have decided to go with six of the LVX 6048 WP inverters running in parallel to handle the loads of my project. I am running 10 bitcoin miners that can range from 1000 to 3200 watts each based on my adjusting. I also have four 300 watt exhaust fans.

The loads are USA single phase (120V/240V) and could reach as high as 34,000 watts if I really pushed things.

I have attached an image diagram to help with my questions:


3) In the LVX 6048 WP manual it recommends a 200A breaker for the batteries. Each inverter has a maximum battery discharging current of 150A, and 120A charging.

I have three 48V 280Ah LifePO4 battery banks, each will have its own breaker on the positive side to serve as protection and a disconnect when working on the system. In a hypothetical situation where there was no solar, and the inverters were running at 34,000 watt output, do you recommend using a larger breaker for each battery than 200A? I worry about 200A being too low, tripping one of the breakers unnecessarily. Perhaps something like 250A or 300A if the system was to pull closer to 1C.

1) I'd like to protect each inverter with a Class T fuse. Ian from Watts247 had a video where he said that 200A breakers for the batteries are overkill and recommends a 125A. I may be being overly cautious, my math is:

6 inverters @ 6000w each
6000 / 48v = 125A / 0.8 = 156.25A ~ 175A Class T fuse.

2 & 4) Also in the manual it recommends 2 gauge wire for the battery connection. Is this sufficient or should be using 1/0 on the battery side?

I am using 1000A busbars to connect everything together.

Thank you, and I appreciate any advice!

 

[MartyByrde]

Here's some photos of what it will look like when done:

 

[n2aws]

Forgetting all details except for the following, I don't think this system works as planned.

32,000w sustained when driven hard.

48v battery bank (lets assume 51.8v nominal voltage lifepo4)

32,000/51.8 = 618 amps (total)

618/3 batteries 206a output per battery ignoring any spikes/peaks, or without factoring in any safety margin..

 

[MartyByrde]

Forgetting all details except for the following, I don't think this system works as planned.

Thanks for the reply. I added some extra info below. Can you please explain why you think it won’t work?

To clarify the system will only run during the day. The loads will turn on in the morning and off during the evening.

The batteries are there to smooth out the solar power during the day. I have 224 250W panels used from Santan, so if they’re outputting ~170w * 224 = 38kw

32,000w sustained when driven hard.

The actual total load will be closer to 22,000 - 27,000 watts.

48v battery bank (lets assume 51.8v nominal voltage lifepo4)

32,000/51.8 = 618 amps (total)

618/3 batteries 206a output per battery ignoring any spikes/peaks, or without factoring in any safety margin..

Are you saying a larger breaker is needed “IF” it was driven hard?

 

[pvgirl]

200amp fuse is a good choice for those inverters if your wire is also rated for 200amps. I would also recommend you consider using a more reasonable table for wire amps rating such as: NEC 2020 310.16 Ampacities of Insulated Conductors in Raceway, Cable, or Earth (Directly Buried)

 

[timselectric]

Agree
200a breaker or fuse, for the AIO's.
You could do the same for the batteries. But I wouldn't want to push them that hard. If you are pushing them that hard. I would recommend more capacity. (Maybe double it)
Whatever you choose, make sure that you size the conductors correctly.

 

[MartyByrde]

But I wouldn't want to push them that hard. If you are pushing them that hard.

Do you mean pushing them at the 32kw and/or the 22-27kw?

I am working on a raspberry pi that is able to reduce the loads based on incoming voltage. I’m trying to think through back up plans if for some reason it didn’t reduce the loads and the solar power dropped off significantly.