Detached Garage Adding Solar and EG4 3kW Inverter

[anuccite]

Couple Verification's about electrical setup for Non Grid tied (Feedback) system

I drew out a quick diagram

1) My main panel is in my house. Normal Ground/Neutral Bond Main panel
2) I have a detached garage on a 100amp Sub Panel. Ground / Neutral Seperate Ground Rods outside of building (as per code when built)

I am beginning my road to start adding Solar to detached garage loads

I plan to use a EG4 3kW Off-Grid Inverter. (one to Start, then add 2nd later in split phase)
To Start, I will not be using a battery (will add as budget allows)

30amp Breaker from Sub panel to Inverter (Ground and neutral still seperate) Black/White/Green

30 amp Breaker in Seperate Breaker panel (for inverter loads)

The Questions are:
1) Do I bring Ground back from the inverter to the Seperate Breaker Panel? and keep my ground neutral seperate
2) Grounding my panels, Where should that grounding be run to? My Grounding Rods?

 

[DIYrich]

I plan to use a EG4 3kW Off-Grid Inverter. (one to Start, then add 2nd later in split phase)
To Start, I will not be using a battery (will add as budget allows)

Make sure the off-grid inverter can run without a battery. Most can't.
Many Grid-tied inverters can run without battery.

If you disconnect the line from the House to the garage, then you can argue you are not grid-tied and avoid the utility hassle. It seems the way you have it wired, it is grid interactive, and thus subject to utility approval. Even though your inverter will not export to the grid.

 

[anuccite]

Make sure the off-grid inverter can run without a battery. Most can't.
Many Grid-tied inverters can run without battery.

I've seen a video posted by EG4 on this unit.... They say it can

 

[Rednecktek]

What are you trying to accomplish? If you're trying to take the garage completely off grid and disconnect it from the house you'll need a battery just to keep the unit alive when a cloud passes by or when the sun goes down. It seems that just running directly from the main panel is MUCH easier and cheaper and gives you more capacity.

If you're just looking to play with solar for the fun then your setup looks pretty good.

1) Do I bring Ground back from the inverter to the Separate Breaker Panel? and keep my ground neutral separate

The way your diagram goes the "Load Panel" would essentially be the main panel on your solar power system, so you'd leave the N-G bonding screw in there.

2) Grounding my panels, Where should that grounding be run to? My Grounding Rods?

In a perfect world you'd run a conductor from the panels all the way back to the garage's grounding rod. If it's really far away though a local grounding rod or plate would be a viable option.

 

[anuccite]

What are you trying to accomplish? If you're trying to take the garage completely off grid and disconnect it from the house you'll need a battery just to keep the unit alive when a cloud passes by or when the sun goes down. It seems that just running directly from the main panel is MUCH easier and cheaper and gives you more capacity.

If you're just looking to play with solar for the fun then your setup looks pretty good.


The way your diagram goes the "Load Panel" would essentially be the main panel on your solar power system, so you'd leave the N-G bonding screw in there.


In a perfect world you'd run a conductor from the panels all the way back to the garage's grounding rod. If it's really far away though a local grounding rod or plate would be a viable option.

Thank you, Great info
I don't think I want to take the Garage completely off the Grid, as I run some larger loads in there on occasion (Saws, compressors, and Dust collection), But Batteries are in my future. It's more of a Lower my energy bill when the suns shining (easten NC).

I have 2 fridges and a freezer, as well as my Office which has a mini-split that runs 24/7. The pool pump is also connected to that Panel.

I have about 1080 sqft of south facing metal roof on the Garage, and plan to purchase a pallet of used 235 watt panels from Santan, Giving me about 5600 watts.... 2 strings 445v. The Grounding Rod will be easy to get to, I just wasnt sure if that was the recommended method.

 

[Rednecktek]

But Batteries are in my future. It's more of a Lower my energy bill when the suns shining (easten NC).

OK, that makes sense. You're still going to want at least 1 battery involved, the last thing you want to happen is you're running a power tool, it shuts off (when a cloud passes by) and starts back up suddenly when you're fumbling with it trying to figure out why it died. Just because a unit CAN run without a battery doesn't mean it can ALWAYS run without a battery, like at night or winter or rain or or or or...

With the saws, compressors, and pool pump all needing 240v you're going to need a pretty substantially huge system to feed all that. It might be worth going with a 6Kw LF version right out the gate rather than throwing away the 3Kw when you go to upgrade because it won't (even in split phase) be able to support the startup surges of larger motors. Another option (budget willing) would be to get the 6Kw LF split phase from EG4 and start your loads panel at 240v right from the start. You'll have plenty of solar to feed it and adding batteries is just time and money later, but you'll be able to move some of the larger stuff over right away (like the mini-split or pool pump) since those are going to be the hardest hitters on your power bill.

 

[anuccite]

OK, that makes sense. You're still going to want at least 1 battery involved, the last thing you want to happen is you're running a power tool, it shuts off (when a cloud passes by) and starts back up suddenly when you're fumbling with it trying to figure out why it died. Just because a unit CAN run without a battery doesn't mean it can ALWAYS run without a battery, like at night or winter or rain or or or or...

With the saws, compressors, and pool pump all needing 240v you're going to need a pretty substantially huge system to feed all that. It might be worth going with a 6Kw LF version right out the gate rather than throwing away the 3Kw when you go to upgrade because it won't (even in split phase) be able to support the startup surges of larger motors. Another option (budget willing) would be to get the 6Kw LF split phase from EG4 and start your loads panel at 240v right from the start. You'll have plenty of solar to feed it and adding batteries is just time and money later, but you'll be able to move some of the larger stuff over right away (like the mini-split or pool pump) since those are going to be the hardest hitters on your power bill.

Food for thought.....

at night, or non PV days... I'm willing to give some money to the man, until I can add the batteries....

The saws and other tools i'd probably keep on Grid power, Just for that reason.... they are just occasional use.

The one nice thing about my pool pump, is that is has a variable speed motor, and there is not a huge surge (I will have to meter check that) once a day it ramps up to a higher speed for an hour . The mini split is 240v, so that is a consideration.

 

[Rednecktek]

The one nice thing about my pool pump, is that is has a variable speed motor, and there is not a huge surge (I will have to meter check that) once a day it ramps up to a higher speed for an hour . The mini split is 240v, so that is a consideration.

So it seems like your two biggest power-bill-culprits are the AirCon and the pool pump. That aircon is going to need a 240v unit to run so you won't get to offload that part of the power bill until you've upgraded to the second inverter and a battery. You don't mention the pump voltage but that might need 240v as well, the only 120v pumps I've ever seen that are 120v are for hot tubs, every pool I've ever worked with has been 240v.

Is this all going to be inspected? If not, have you considered DIY'ing a battery? It's MUCH cheaper than a pre-built which helps with the budget. The power coming in and out without a battery concerns me as an end user and power tool repairer person, motors don't like that much and it seems dangerous.

Granted I'm not as familiar with those units as I wish I could be. Will it draw power from the main panel to prevent power interruptions for night/clouds/rain? If it does then disregard my paranoia. ?

 

[anuccite]

So it seems like your two biggest power-bill-culprits are the AirCon and the pool pump. That aircon is going to need a 240v unit to run so you won't get to offload that part of the power bill until you've upgraded to the second inverter and a battery. You don't mention the pump voltage but that might need 240v as well, the only 120v pumps I've ever seen that are 120v are for hot tubs, every pool I've ever worked with has been 240v.

Yes, Pool pump is 240....

Is this all going to be inspected? If not, have you considered DIY'ing a battery? It's MUCH cheaper than a pre-built which helps with the budget. The power coming in and out without a battery concerns me as an end user and power tool repairer person, motors don't like that much and it seems dangerous.

Not inspected. But I just dont want to go through the hassle. The Eg4 batteries are fair in price. But i'm hoping to do things in phases

Granted I'm not as familiar with those units as I wish I could be. Will it draw power from the main panel to prevent power interruptions for night/clouds/rain? If it does then disregard my paranoia. ?

Yes, It seems like all the newer EG4 models have an option for "PV 1st, then Grid when needed" and also, "PV, Battery, Grid" I can Create a split phase with additional, as well as Parallel and series 2 sets (as budget allows)

 

[Rednecktek]

Aaahhh, that makes more sense then. So, having gone through all that, it looks like your diagram is pretty much good to go.