A/C Setup Questions for SPF Growatt 5000Es (US)

[Dskvid]

Hello I just ordered from Texas a Growatt SPF 5000ES, 2 x Eg4 48v 100Amp batteries, and the transformer to balance 120volts. This is my 1st dive into solar and wish to start out as a UPS for a Well pump and a few select 120 loads. I will locate system in my unfinished basement about 30 feet away from House service panel. I want to run A/c power to Inverter and also run a 220 line back directly to the well pump which is back by house service panel. Currently the well pump runs off a 220v 20amp breaker. I will have small breaker panel next to the Growatt inverter for outbound 220/120 feeds. On the input side I believe I see in the Manual they recommend a 50amp breaker for the A/c input side, this will not be in the outbound breaker box. So I assume i'll have a 220v 20amp breaker in my solar breaker panel then run that back to well pump. Im getting confused by Romex wire sizes needed for this distance especially for the 50 amp inbound feed to the inverter, and i would assume leaving the house Service panels would need a 50amp breaker there to start? I/m looking for any good diagrams and advice to help plan this please.
I will also be running 3 370watt 120 cell panels on a ground mount to as my solar power side.

Thanks, Im excited and interested in this community and hope to some day be on the info providing side but for now, I'm a newbie.

 

[timselectric]

I have the same inverter.
30a breaker in the main existing panel. 10/3 with ground romex to input of inverter. 50a breaker in New loads panel. #8 from output of inverter to 50a breaker. #10 white from inverter to loads panel neutral bar. Connected to white in inverter from main panel with a wire nut. (Not connected to anything else in the inverter) ground wire from inverter output to ground bar in loads panel. Ground bar should be connected to the loads panel box. Neutral bar should not. Autotransformer can be wired to the loads panel, either by breaker or to the main lugs. I prefer the main lugs. So that it can't be disconnected unless the panel loses all power. (A loss of neutral can damage 120v devices)
I'm not sure if you have enough solar voltage to start up the MPPT. What voltage are your panels?
That's enough to get you going. If you have any other questions, I'll be happy to help.

 

[Dskvid]

I think my panel are enough I hope.

ZNShine Solar 370W Solar Panel 120 Cell ZXM6-NH120-370/M

• Rated Power Output 370 W
• Voltage (VOC)41 V
• Cell number120 cell

 

[timselectric]

You need a minimum of 150v to start up the MPPT.
And at least 120v to keep it producing.
That's VMP, which is about 15 to 18% less than VOC.
Your panels are probably about 34 VMP.
3 x 34 = 102

 

[Dskvid]

Prefect in a sad way

 

[timselectric]

Sorry
But, it's better to know now. Than trying to figure out why it isn't working, later.

 

[Dskvid]

I know I appreciate your help. So the inverter says it’s MPPT operating spec is from 120Dc-430Dc. So if I buy another panel based on a VMP of 34.2 x4 = 136.8 is that enough to kick it on or do have to add another panel to be over 150? I intended to put in series.

 

[timselectric]

It really needs at least 150v to start the MPPT.
Higher is always better.

 

[Dskvid]

I have the same inverter.
30a breaker in the main existing panel. 10/3 with ground romex to input of inverter. 50a breaker in New loads panel. #8 from output of inverter to 50a breaker. #10 white from inverter to loads panel neutral bar. Connected to white in inverter from main panel with a wire nut. (Not connected to anything else in the inverter) ground wire from inverter output to ground bar in loads panel. Ground bar should be connected to the loads panel box. Neutral bar should not. Autotransformer can be wired to the loads panel, either by breaker or to the main lugs. I prefer the main lugs. So that it can't be disconnected unless the panel loses all power. (A loss of neutral can damage 120v devices)
I'm not sure if you have enough solar voltage to start up the MPPT. What voltage are your panels?
That's enough to get you going. If you have any other questions, I'll be happy to help.

Hello Again, I like the setup you have and would like to follow it. I would like to mount the system at about 40sh feet from the house panel in an unfinished basement. I was thinking that i would need A 50 Amp breaker from the Grid Panel to my inventer and a 50 amp back from solar power loads panel to a new sub panel next to the Grid panel with a Inner-lock breaker. As i started to price cable for 6 gage wire the cost really added up howeverI see your using a 30amp from the house panel on 10/3 and a 50 on the output side with 8gage wire? I also like what you did with the Transformer. Do have a diagram of all this so I can make sure I have everything correct? Thanks

 

[timselectric]

Sorry, no diagram. It's all in my head.
But, I can answer questions along the way.

 

[timselectric]

30a input is all that you will ever draw.
22a is the inverter max output. But in SUB mode, this inverter can power the loads from inverter and grid together. This is the reason for the 50a output rating.

 

[Larry Oswald]

I have the same inverter.
30a breaker in the main existing panel. 10/3 with ground romex to input of inverter. 50a breaker in New loads panel. #8 from output of inverter to 50a breaker. #10 white from inverter to loads panel neutral bar. Connected to white in inverter from main panel with a wire nut. (Not connected to anything else in the inverter) ground wire from inverter output to ground bar in loads panel. Ground bar should be connected to the loads panel box. Neutral bar should not. Autotransformer can be wired to the loads panel, either by breaker or to the main lugs. I prefer the main lugs. So that it can't be disconnected unless the panel loses all power. (A loss of neutral can damage 120v devices)
I'm not sure if you have enough solar voltage to start up the MPPT. What voltage are your panels?
That's enough to get you going. If you have any other questions, I'll be happy to help.

Solid information. Tim, why do you say AUTOtransformer? How is this transformer connected and what is the purpose?

 

[timselectric]

Solid information. Tim, why do you say AUTOtransformer? How is this transformer connected and what is the purpose?

An autotransformer only has one set of windings.
It's only purpose (in this case) is to create a neutral for split-phase configuration. It only carries the unbalanced load.

 

[Larry Oswald]

GE Transformer 9T51B0013 Type QB 3KVA 60Hz 1Ph 240/480 120/240 is a regular two winding input and output transformer that will transform a european or asian 230VAC inverter output into 240VAC and TWO 120VAC split phases. These transformers are available on EBay and Marketplace for under $200. I suspect they are widely used for commercial lighting. I have a1KVA 9T51B0010 in my experimental setup and two of the 3KVAs for a more permanent install next winter.

Is there a down side I am missing?

 

[timselectric]

GE Transformer 9T51B0013 Type QB 3KVA 60Hz 1Ph 240/480 120/240 is a regular two winding input and output transformer that will transform a european or asian 230VAC inverter output into 240VAC and TWO 120VAC split phases. These transformers are available on EBay and Marketplace for under $200. I suspect they are widely used for commercial lighting. I have a1KVA 9T51B0010 in my experimental setup and two of the 3KVAs for a more permanent install next winter.

Is there a down side I am missing?

Those are isolation transformers. They will work, but less efficient. Because they carry all loads, all of the time. But, if you are going to have the grid connected to the AC in, it's the safer way to go. But, you need at least 5kva per inverter.

 

[Larry Oswald]

Those are isolation transformers. They will work, but less efficient. Because they carry all loads, all of the time. But, if you are going to have the grid connected to the AC in, it's the safer way to go. But, you need at least 5kva per inverter.

Tim. Never thought about the throughput. [I have a EASun 3.6KW 230VAC output] For an AUTO transformer the connection is is to the AC out labeled as N and L (but in my case mislabeled, actually both floating). The autotransformer creates split phase and the only throughput is on the center neutral of an amount of the unbalance of the two 120VAC legs. Is this true?

So the secondary of my isolation transformer could be used in this way?

Can the 230VAC inverter output be used directly to any pure US 240VAC appliances like a water heater or pump? The latter is important for long term power outages for toilet flushing etc.

Can a 230VAC output be sent BOTH direct to some pure 240VAC circuits and also to an isolation transformer primary?

I am thinking mostly of stand alone no grid connection.

 

[timselectric]

Yes, to all.
You made it easy to answer.