Need help growatt & Bluetti 200p

[Wendbr]

My husband is disabled, our power goes out frequently and he needs power for oxygen concentrator.
I need plans/blueprint/part list for ….

Growatt 24v 3000
Panels will be 25’ from all in one
Not tied to grid

Bluetti ac200p
Panels 25’ from Bluetti

Thanks in advance for any & all help you can provide me. I’ve been reading and researching till my mind is fixing to blow!

 

[Northernchateau]

Please take a picture of the label on his oxygen concentrator and post it.
The volts, amps, watts are needed to determine the system requirements.
Also please estimate how long you think it will need to run without grid power.

 

[Wendbr]

Please take a picture of the label on his oxygen concentrator and post it.

The volts, amps, watts are needed to determine the system requirements.
Also please estimate how long you think it will need to run without grid power.

24 hours. We have a honda generator I can charge batteries up when need be. I know Bluetti will only run concentrator about 6 hours. I’m soooo confused on wire sizes, fuses & blueprint

 

[snoobler]

Please take a picture of the label on his oxygen concentrator and post it.

24 hours. We have a honda generator I can charge batteries up when need be. I know Bluetti will only run concentrator about 6 hours. I’m soooo confused on wire sizes, fuses & blueprint

3.4A @ 120V = 408W

It probably uses less than that, but it's good to be conservative. Given the 6 hour run time of the Bluetti, this isn't too far off the mark.

The Growatt will burn another 50W.

458W/0.85 = 539W (account for inverter inefficiency)

24hr * 539W = 12,936Wh - daily energy consumption

DIY LFP batteries will run you a little over $2000

Why not connect to grid? Not grid-tie, but at least have grid input to the charger. It can effectively be a UPS for the concentrator. You could have an ATS that could select between grid and generator.

The Growatt is limited to 2000W solar, so you'll have a hard time producing the needed 12936Wh unless you have fantastical sun, but you'll only have a deficit of about 2000Wh/day meaning, with good sun, you'll have nearly a week of running purely off solar. You can supplement with generator. I would look at overpaneling to something over 2400W to try and narrow this gap.

Is the Bluetti a backup to the backup?

Do you already have the Growatt? It's a little wonky with AC input from grid or generator.

 

[Wendbr]

3.4A @ 120V = 408W

It probably uses less than that, but it's good to be conservative. Given the 6 hour run time of the Bluetti, this isn't too far off the mark.

The Growatt will burn another 50W.

458W/0.85 = 539W (account for inverter inefficiency)

24hr * 539W = 12,936Wh - daily energy consumption

DIY LFP batteries will run you a little over $2000

Why not connect to grid? Not grid-tie, but at least have grid input to the charger. It can effectively be a UPS for the concentrator. You could have an ATS that could select between grid and generator.

The Growatt is limited to 2000W solar, so you'll have a hard time producing the needed 12936Wh unless you have fantastical sun, but you'll only have a deficit of about 2000Wh/day meaning, with good sun, you'll have nearly a week of running purely off solar. You can supplement with generator. I would look at overpaneling to something over 2400W to try and narrow this gap.

Is the Bluetti a backup to the backup?

Do you already have the Growatt? It's a little wonky with AC input from grid or generator.

The growatt and Bluetti will be here Wednesday. Yes the Bluetti is a backup to the backup. All that grid stuff is way over our head.

 

[iamrich]

The growatt and Bluetti will be here Wednesday. Yes the Bluetti is a backup to the backup. All that grid stuff is way over our head.

I would definitely plug into the grid. You just run an extension cord from any standard outlet to the AC IN on the Growatt. The whole system then becomes a UPS. You can still use the solar all day long, but if the batteries get low, grid kicks in.

 

[T.C.]

... I’m soooo confused on wire sizes, fuses & blueprint

Gauge of wire depends on at least two components: the current the wire needs to carry and the distance (length of the wire)

If I understand correctly, the maximum solar charge current is 80 A, while maximum AC charge current is 60 A for this Growatt. That's 140 A in total. (Maximum AC charge current is configurable and can be lowered on the unit.)

In terms of wire size between the Growatt and battery pack, first determine the length of wire needed to connect the two. Now knowing the current that the wire will carry and the wire length, the appropriate wire gauge can be found here: http://assets.bluesea.com/files/resources/newsletter/images/DC_wire_selection_chartlg.jpg

Regarding fuse at the main positive battery terminal. Using the 125 % rule and max current of 140 A means: 140 A * 125 % = 175 A fuse.

Disclaimer: I attempted answering parts of the question as a means of learning. I may be completely wrong. Hopefully the community will point this out if it is the case.

 

[T.C.]

I ended up looking in the manual and the following is suggested:
- 8 gauge for AC wires
- 6 gauge for solar wires
- 2 gauge for battery wires (the stated maximum amperage is 164 A, so I was off by 24 A)

Note that the total charging current (solar + AC) is by default configured as 60 A on this Growatt. Furthermore the manual recommends installing a 40 A breaker at the AC input.

 

[T.C.]

@Wendbr, is the oxygen concentrator used 24/7? I know there are cases where at least 16 (and up to 24) hours of oxygen per day is prescribed. In other instances I have heard of the prescribed amount being around 8 hours per day. Snoobler's estimate is based on 24 hours use each day, which very well could be the case.

 

[T.C.]

...

Do you already have the Growatt? It's a little wonky with AC input from grid or generator.

@snoobler, can you say more? I am planning on getting the Growatt SPF 5000 ES.

 

[Northernchateau]

The growatt and Bluetti will be here Wednesday. Yes the Bluetti is a backup to the backup. All that grid stuff is way over our head.

That being said, whom is going to assemble the components you purchase?
There is a whole lot of stuff still missing and it might be worth finding someone to built and install everything you will need to code, safely.

 

[snoobler]

@snoobler, can you say more? I am planning on getting the Growatt SPF 5000 ES.

Most (if not all) of the Growatt series do not have typical AC charging modes when in SOL or SBU modes. Their AC chargers do not use the Absorption and float values. The AC chargers come at a set low voltage and then turn off immediately after attaining the set high voltage. See settings 12 & 13.

https://watts247.com/manuals/gw/SPF%205000%20ES%20User%20Manual.pdf

 

[Wendbr]

I would definitely plug into the grid. You just run an extension cord from any standard outlet to the AC IN on the Growatt. The whole system then becomes a UPS. You can still use the solar all day long, but if the batteries get low, grid kicks in.

@Wendbr, is the oxygen concentrator used 24/7? I know there are cases where at least 16 (and up to 24) hours of oxygen per day is prescribed. In other instances I have heard of the prescribed amount being around 8 hours per day. Snoobler's estimate is based on 24 hours use each day, which very well could be the case.

Yes 24 hours

 

[Wendbr]

That being said, whom is going to assemble the components you purchase?
There is a whole lot of stuff still missing and it might be worth finding someone to built and install everything you will need to code, safely.

We are in upstate SC if you know anyone who can assemble for us.