Want to make my Main panel my sub panel. What do I need to know?

[jazclrint]

Afternoon all. I'm not on here much but planning an upgrade to my current system that I want to do in small steps.

Here's what I have:

• In SW Florida
• 29 370W panels totaling 10.7kW. 21 on the East roof, and 8 facing west.
• Solar system is AC coupled with Enphase IQ8+ micro-inverters. (that survived the last hurricane, knock on wood!)
• Emporia Vue 2 with about 2 years of data
• 2 Chevy Bolts that we Uber with. We are on FPL's $32/month unlimited charging plan effectively separating EV charging from house usage.
• Many improvements to home efficiency: Heat Pump water heater, new variable speed pool pump, heat pump all-in-one Washer/dryer combo that works, smart LED bulbs and smartified ceiling fans to help with power reduction, and even a cordless robot pool cleaner which saves a surprising amount over the old vacuum. It's a bit hard to get super clean data (for so many reasons) but it looks like we have reduced the house's daily usage by at least 20kWhr a day (or almost half) from when we moved in 5 years ago.
• Oh, and I was an airplane electrician in the military. So I have electrical knowledge, just not in this stuff.

Here's what I want when finished:

• Whole home system where all we do is sell power to the power company, accept for the car charger. That is also storm ready and able to handle car charging in the future.
• about 30 more panels making the system about 20kW or more.
• Victron solar charge controller(s) and inverters (about 16kW worth) running the new panels
• close to 40kWh of DIY LFP battery.

For me, after a lot of thinking, the first step is to install a new Main breaker panel. I need to do this project in small steps. Pick a thing and get all the little things that make it right. Since I want to back up the whole house I don't see the sense in moving all the circuits over to sub panel. Why not put up a 12 slot 200A main panel ( I have 200A service) and move over the 5 power intense circuits over to it? All of them are 240V circuits, btw. Have 2 years of data from my Emporia Vue2 so I know how much each circuit uses. And I know I can run the rest of the house off of 2 Victron 3k UL inverters.

Here's the 5:

• Enphase solar circuit (240)
• Range (240)
• AC (240)
• Heat (240)
• Car charger (stays, forever?) (240)

The last 2 slots will be the wires carrying power over the old main/New sub panel. That circuit will then become the circuit for the first 2 3k inverters. Once I get the second (or 3rd?) set of inverters I can put all the circuits back accept the car charger (which is a subscription from my power company). And if you are wondering, I am planning on putting the inverters in after I get the first 3 stages of DIY FLP battery packs built and ready.

As far as my plan with the putting in a new main panel, what don't I know? What about permitting? Do I need one? I suspect I will where I'll also be moving the big power wires (service wires?) over to the new panel as well.

Thank you for your time,
Richard

 

[DIYrich]

You will need a permit.

I didn't see in your plan a device that keeps the enphase producing when grid is down, and an isolation switch.

If it were my project, I would put an 18kpv or 15k between the meter and the main panel, and have the enphase come into the inverter as AC PV via the gen/Smart Load port. The inverter will provide the "grid" to keep the enphase running, and has an isolation switch when the grid goes down.

 

[1201]

Thanks for the detailed write up and for your service.

So once you've moved those big loads off your future sub panel, how much power do the rest of the circuits actually use per month?

 

[jazclrint]

You will need a permit.

I didn't see in your plan a device that keeps the enphase producing when grid is down, and an isolation switch.

If it were my project, I would put an 18kpv or 15k between the meter and the main panel, and have the enphase come into the inverter as AC PV via the gen/Smart Load port. The inverter will provide the "grid" to keep the enphase running, and has an isolation switch when the grid goes down.

Thought so.

That's because that is further down the road, and I am trying to concentrate on the small steps before me. I am going to use Victron 3k UL inverters, and so far plan to add one set at a time. Victron has formulas for the amount of battery and inverter power needed to deal with AC coupled solar systems. Once I meet that amount I plan on moving the solar circuit back to the old panel which the inverters will power at that point. I thought that the Enphase system would keep working if setup like this. I also suspect that my IQ8's might be even smarter and pose less of a risk of over powering my system, should that ever be an issue when the grid is down. But as I have yet to actually DO anything and am miles from this point, I haven't bothered any professional experts with my questions. In the meantime, having the Enphase system between the grid and the inverter instead of after will work, keep things safe, and keep the system on full blast as it is currently. So, until I have built up enough battery and inverter power to saticfy Victron's requirements, and move the Enphase circuit to after the inverters, it will continue to shut off during a power outage. Which I am OK with. I'm not into shocking line workers. Starting with inverters and batteries first means I can use the ESS and switch to TOU pricing and save some money. Also, we'll have a bit of power if the power goes out. It is a delayed gratification plan, for sure.

 

[jazclrint]

Here's a code question, if anyone knows. To the left of my breaker panel about a foot or so are the hot and cold water lines for the washing machine running vertically from the attict. Can I cross over, perpendicular to those water lines with electrical conduit? If I could avoid this I would, but I can't really. Any ideas?

Also, has anyone built a system like this in an FPL (Florida Power and Light) area? In your experience, what are their requirements?

Thank you for your time.

 

[zanydroid]

Here's a code question, if anyone knows. To the left of my breaker panel about a foot or so are the hot and cold water lines for the washing machine running vertically from the attict. Can I cross over, perpendicular to those water lines with electrical conduit? If I could avoid this I would, but I can't really. Any ideas?

I did this at my home with EMT only 3 months ago. I believe I checked online for code compliance beforehand. And it also feels uber safe. Safer than in wall romex. I did secure to studs on both sides of the jump over the plumbing

You can ask on a general electrical code help forum for the answer.

 

[DIYrich]

Here's a code question, if anyone knows. To the left of my breaker panel about a foot or so are the hot and cold water lines for the washing machine running vertically from the attict. Can I cross over, perpendicular to those water lines with electrical conduit? If I could avoid this I would, but I can't really. Any ideas?

Also, has anyone built a system like this in an FPL (Florida Power and Light) area? In your experience, what are their requirements?

Thank you for your time.

Water and electric cross all the time. The problem may be how close the main panel is to the water. There may be a recent code update related to that. You would be grandfathered up to a certain point of improvements.

 

[jazclrint]

Thanks for the detailed write up and for your service.

So once you've moved those big loads off your future sub panel, how much power do the rest of the circuits actually use per month?

Ah, I haven't been worried about per month, but peak load pulled. 15 min peak load with the 48A EVSE and AC running full blast, and cooking for 5 in the kitchen this summer so far was just under 16kW. Assuming the charger was only pulling 10kW (peak it can pull is almost 11.5kW) that is 7kW for the house. Honestly, removing the A/C, Heat, and Range, will drop that 7kW dramatically. But I was going to make a 30A circuit from what will be the new Main panel to the old panel that will be the sub panel until I get the first set of inverters. But oversize the wires as the load will be constant and leave room to uprate the circuit breaker if needed.

Thinking about it some more and seeing real-world testing of a set of 3k inverters on YouTube, and with the data I have of my power usage, I suspect I could keep the Range on the old panel. But best not to push it.

A side note, I did realize I'll have to un-bond the Neutrals and grounds when I make the old Main panel a sub-panel.