400-amp Service - Selective Cricut Battery Backup

[mbaker_wv]

Hello everyone,

I'm new to the forum and encountering an issue when attempting to search for previous posts – I keep getting an 'Oops, error has occurred' message. Any suggestions? I'd like to explore similar discussions.

My wife and I own a 2200 sqft, single-level rancher-style home built in late 2020. The front faces due south, while the back faces due north. We typically experience 2 or 3 power outages a year, lasting anywhere from 30 minutes to 12-16 hours.

While we're not looking for a comprehensive home backup solution, we aim to keep essential circuits active during outages, including lighting, refrigerator, well pump, and sump pump.

Here's the challenge: We have a 400-amp service with 2-200 amp panels installed in the basement. This setup was intended for a future pole barn, planned for installation when building costs decrease. I want to connect a few circuits from each panel to a battery storage solution. Additionally, I'm considering installing 4 to 6 ground-level solar panels to charge the batteries gradually. The goal isn't to charge the batteries in a single day but to maintain essential circuits and allow a few days for recharging.

My question is, how challenging is it to separate these circuits and connect them to the proposed system? Do I need a separate sub-panel, or is there a transfer switch available for this purpose?

Thanks in advance for your insights!

mbaker_wv

 

[BentleyJ]

Sounds like there are few circuits in each of the 200A Panels you are considering as critical loads. Without a picture or diagram of the specific electrical system all we can do is list some options. All options below assume at least 1 battery back up inverter is installed, perhaps even 2.
1) Add a critical loads subpanel. The best case scenario is the 2 existing 200A panels are side by side with enough wall space to add the critical loads subpanel next them such that existing wiring is long enough and the breakers could simply be moved into the new back up panel. Otherwise the circuits of interest could be pulled out of the 200A panels and placed into a junction box so extension wires could be spliced on to reach the new subpanel.
2) Move all the critical load breakers into one of the existing 200A panels and use a battery back up inverter only on that panel.
3) Add something like a Sol-Ark load control panel to cut large unnecessary applliance loads in the existing panel(s) during a power outage.
4) Replace one or both existing 200A panels with Leviton Panels and Smart Breakers with shunt trip option. This is another way to achieve load control in an outage.
EDIT: 5) Check out Reliance transfer switches. This is basically a variation of Item #1.

 

[mbaker_wv]

Thank you BentleyJ
I was thinking the solution would be with a new subpanel, but I didn't know how the technical side of this would work if we took these circuits from their home panel and just moved them into the new sub panel. I would want the circuits to remain energized off grid power until power went out. The solar cutover could be manual or automatic, im not opposed to either option. I'm fairly new to battery calculation but i feel like 2 100ah batteries should keep things online 12-16hours.
Please feel free to comment on design below and if this would be doable or if others would do it another way.

mbaker_wv