Solar "Sub Panel" or other methods?

[dmkjr]

I've looked around and found a few people asking something similar, but it seems most people have the intent of replacing their main utility feed to go "off-grid".

I want the ability to select circuits that I can move over to my inverter(s) to provide power via my solar setup / batteries. I currently have a Reliance 10 circuit manual transfer switch and am using it for 10 different 120v circuits. Now, I need to be able to tie in more circuits so I'm debating. Do I add another Reliance 10 circuit manual transfer switch or is there another (potentially better) way to do this?

I have done all the work myself to date (and have it reviewed by a family member, electrical engineer). I'm confident in my ability, just not sure how you all are doing it. I saw a YT video today where a large install had 4 of the Reliance transfer switches so he could go back and forth from Utility and Solar/Battery setup from the inverters.

Thank you!

 

[Crowz]

Sounds like your wanting to do what I have running.

Meter > Main Breaker Box > Breaker installed in the Main Box > Inverter > Sub Panel > Breaker in sub panel box.

The breaker in the sub panel box provides a disconnect from the sub panel box and the inverter in case of problems or for maintenance.

Then move whatever circuits you want to run off the inverter from the main box to the sub panel box.

If you get low on space or have a spare breaker/mini box then add a breaker in between the inverter and the sub panel box. This will free up the slots the sub panel breaker mentioned before is taking up. But if you don't have one handy (Like I ran into) then just have a breaker in the sub panel box that the inverter feeds into. As long as that breaker is on the sub panel is live aka working.

 

[JustOnePanel]

It really depends on the use case. Powering the entire panel, a smaller critical loads panel or individual circuits as needed.

I started my solar journey a few months ago with a critical loads panel setup exactly as described above, then I quickly pivoted to a transfer switch setup for 2 reasons:

1. I realized that any hardware issue with the inverter(s) would most likely not be resolved quickly and all my critical loads would need to be re-wired to the main panel to make them functional again. Straight-forward work if I'm at the location, very complicated if I'm not.
2. I wanted the ability to flip individual critical circuit loads between solar/battery and grid

So the new setup is based on a 10-circuit protran off my main panel with 2 x EG4 3000s in split-phase serving as the "Gen" input to the reliance transfer switch. The EG4s get AC in from the main panel. If I needed to expand it I'd add another protran and 2 more inverters.

 

[Crowz]

It really depends on the use case. Powering the entire panel, a smaller critical loads panel or individual circuits as needed.

I started my solar journey a few months ago with a critical loads panel setup exactly as described above, then I quickly pivoted to a transfer switch setup for 2 reasons:

1. I realized that any hardware issue with the inverter(s) would most likely not be resolved quickly and all my critical loads would need to be re-wired to the main panel to make them functional again. Straight-forward work if I'm at the location, very complicated if I'm not.
2. I wanted the ability to flip individual critical circuit loads between solar/battery and grid

So the new setup is based on a 10-circuit protran off my main panel with 2 x EG4 3000s in split-phase serving as the "Gen" input to the reliance transfer switch. The EG4s get AC in from the main panel. If I needed to expand it I'd add another protran and 2 more inverters.

I have that setup at my old house. Its a reliance controls pro/tran 2 panel. Talk about a spaghetti looking mess. Unit works great but first time opening the box and seeing all of those wires was a bit daunting.

My solution at the new house was using two breakers in the sub panel at the top and a transfer switch lockout plate. Left hand breaker is power from inverter and right hand breaker goes to the generator plug.

Doesn't natively solve any inverter failures but does add a way to power the panel in a power outage/inverter failure from the generator.

 

[JustOnePanel]

I have that setup at my old house. Its a reliance controls pro/tran 2 panel. Talk about a spaghetti looking mess. Unit works great but first time opening the box and seeing all of those wires was a bit daunting.

My solution at the new house was using two breakers in the sub panel at the top and a transfer switch lockout plate. Left hand breaker is power from inverter and right hand breaker goes to the generator plug.

Doesn't natively solve any inverter failures but does add a way to power the panel in a power outage/inverter failure from the generator.

haha very true! You can route that spaghetti nicely around the panel but it's still a lot of spaghetti (22 wire runs specifically for the 10-circuit protran)

 

[ArthurEld]

I am looking forward to the day I have an inverter that can go between the meter and the main panel so it just runs everything. And all of the spaghetti and sub panels go away.

 

[dmkjr]

@Crowz and @pm443 Thank you for the feedback. I currently have basically the same thing as the ProTrans manual transfer switch. I just purchased another unit this morning but was looking for something a little cleaner than the multiple transfer switch boxes.

My next hurdle is the layout. Currently I have my inverter (6500ex), GEN input (for adding a generator should my mains and inverter/battery not able to provide juice), a Reliance 10 circuit transfer switch box, EG4 battery communication center -- all mounted to concrete board located next to my main house panel (which is flushed into the wall). I'm trying to think of the best way to keep it all uniform but everything is surface mounted except for the main breaker panel.

I'm thinking about adding another EG4 6500ex -- but I struggle with the need. My wife keeps our house at 69-70 degrees pretty much year round (maybe not in the winter 66-67). I'm worried about the battery capacity I would need to be able to support running 3 A/C units (pretty much the only need for 240v). I do have an oven (we hardly ever cook at home) and a dryer that is 240v. If I could get all of the 120v items off my main and supported by Soler, it would eliminate 75-80% of my electric bill. I currently have 5kw in panels installed, installing another 5kw within a week or two.