[Frank777]

Sounds really interesting. The winter test is definitely an important one.

Any thoughts on how resilient the system is? Could it survive an EMP/Carrington event?

I'm not exactly sure how one would test for that. But I'm the kind of nutcase that would want some assurance I could get the system up and running after a serious electrical outage and the Tesla office is swamped with repair requests. The way the world is headed, I'm sure there are several governments who already have computer viruses-at-the-ready to take down batteries and panels should the winds of war blow in the wrong direction.

If I spend this kind of crazy money on home electrical generation, I want some guarantees I'll be able to use it when it's most needed.

[turtle]

I do not have a hardened system per se. What I do have though is the area most of my gear is in with surrounded by concrete on all sides because it is in the basement. So that will help, but the panels are of course exposed.

Since my system is all wired networking, I can just disconnect it from the network and would be able to ensure production without outside control. The Span Panel does have cellular built in, but that is "fixable" too.

[turtle]

I've order two "soft starters" for the AC compressors. They are supposed to reduce the initial spike and general current consumption. I only recently discovered these were even a thing but apparently they are "magic" to reduce the spike and prevent the compressors from tripping generators and batteries.

[turtle]

The install is done and man do they REALLY make a difference. Well, when wired properly that is.

To start off, my inrush on my 4 then 3.5 ton:
121.3 and 113.1


Then after install with 4 ton then 3.5 ton:


Now after learning with 5 starts overnight:


Start up inrush went from 121.3A to 34.5A on the 4 ton conventional condenser. This was a 71% reduction in inrush current!
Start up inrush went from 113.1A to 28.4A on the 3.5 ton heat pump condenser. This was a 75% reduction in inrush current!

Two Powerwalls have a max sustained output of 60A. Peak output is 64A. With these soft starters I shouldn't have any problems going off grid again and the condensers kicking on even with other loads. Maybe not the dryer or oven/stovetop too, but you get the idea.

Install was pretty straight forward. My step bit absolutely sucks and I kind of mangled the bottom of the heat pump electrical box getting the hole in it for the cable clamp. I was able to get the holes drilled and cable clamps on then feed the harness through. I terminated the ends of the harness in the house so I didn't have to fight it outside at the units. I still had to do two crimps out there, for the start winding (butt splice). All my terminals in the electrical box for the condenser had spade terminals so I just connected up with those. I did read that if the run winding has a higher than 18A rating that you should use a ring or fork termination instead of spade, so I did.

Everything was great except I accidentally put the orange wire on the common terminal of the cap instead of the herm terminal. Thankfully the soft starter just gave me an "F" on the install and told me to try again rather than burn up my condenser or something like that.


For right now the soft starters are not permenately mounted because I haven't figured out how exactly I want to do this. I don't like the idea of putting holes in my panel and sticking something in the ground seem overkill. For now I have the 4 ton one wedged above the freon lines and the 3.5 ton one zipped to the freon and power conduit.


If you're curious, this is the correct wiring for both of my units even though they are conventional and heat pump.


Yes, I'm thrilled with the results of these units!

[PB PM]

Our AC unit supposedly came ready for solar power, not sure if that means you could power it from solar independently, or whether it would have to be part of a whole home system. I'm sure we'd need a bunch of panels to run it.

[turtle]

It might mean it is ready to run from DC output of a panel (or string of them). Some of the mini split systems are built with that ready. I'm not sure about full size residential ones though, I'd have to see the specs to know more.

The kind of system I have means everything in the house in "normal" for power connections. My system just provides the voltage and amperage needed to run the loads.

[PB PM]

I don't remember the model, I'd have to dig into the manual. I just know it's a higher end Lennox AC unit from 2020. Thankfully electric power is only like 11 cents per kwh here, so unless the price sores I doubt we'll put solar on it anyway.

[Kickaha]

Originally Posted by turtle It might mean it is ready to run from DC output of a panel (or string of them). Some of the mini split systems are built with that ready. I'm not sure about full size residential ones though, I'd have to see the specs to know more. The kind of system I have means everything in the house in "normal" for power connections. My system just provides the voltage and amperage needed to run the loads.

That's the goal I'm heading towards.

HOWEVEH... I had a coworker a decade ago whose hobby was reducing his home electricity use without impacting his lifestyle. He went so far as to install a low voltage network in his walls, 5V / 12V DC, and bypass the transformers in his home electrical equipment. His AV rack was completely DC, for instance. Ran 20°F cooler in the AV closet, and used 15% less power. He put in high efficiency transformers in several locations, and ran low voltage lines where he needed.

Bonus, was that it was solar ready. He spliced in the battery bank to the DC system, and could run straight battery -> DC devices with no losses from conversion. Last I heard, he was doing the same with his lighting in his home, converting it to 5/12V LEDs.

Hell, he probably has his oven running on DC at this point...

[turtle]

You know, this building I'm doing for my greenhouse is kinda going that direction. I ordered the wrong bulbs for my kitchen and they will end up being my lighting for my greenhouse. I should have ordered 120VAC LEDs but got 12VDC instead.

Well, my greenhouse is going to be 12VDC with a buck converter for 5VDC circuits too.

I could imagine doing that through the whole house on a new build, but less so on an existing unless it were a single floor ranch with no firebreaks in the walls.

[turtle]

Today became the day I tested my soft starters off grid. Once my PV system got installed my only option with my electric company was to go Solar Time of Use. This means I don't get true 1:1 net metering, I have a minimum electric bill of $30, and to top it off, the electric company can call up to twenty "Critical Peak" pricing periods per year. The heat has made today and tomorrow two of those twenty days.

So at 1800 when the critical peak started I disconnected from the grid to ensure I don't accidentally pull from it at $.26kWh. I left everything running normally in the home, including the climate control. Both condensers have been running off and on since and not once have I noticed the lights flicker let alone drop my electrical system. This really was the answer I was looking for!

Just because, screen caps of the stats:
Grid off:


Batteries charging and consumption showing no condensers running:


One condenser kicked on and is pulling from the batteries:


Consumption showing both systems running:


Stats from the EasyStarts:


The "240V Subpanel (Left)" is the circuit that houses the breakers for the main floor 4 ton system.

I should also add that I did "properly" mount the EasyStarts on the condensers:

[turtle]

This is my production for today. We maxed at 15.2kW (inverter capacity):

The peak output is actually 64A. Truth be told it will spike even higher but for a SUPER short period. Milliseconds. One example I saw even tonight was with the basement system running the main floor one kicked on and I registered 11.5kW... my max continuous is 10kW. It leveled out though at 7.6kW:

That screen cap was taken right before the 50% mark and the Panel shed most of my loads. Just before we ended critical peak we lost the bulk of the loads due to shedding by Panel:


The big thing to note here is the Gateway doesn't have a clue how much time we actually have because it assume all loads and calculates remaining charge based on current use. As in, right now. No historical or trends. Panel is able to base remaining charge on trends and knowing it is about to make it hot in here by shedding my climate control and other "Nice to have" circuits.



We are back on the grid and will call this a complete success! I'm so happy with these EasyStarts! Really, I'm impressed.

[drewprops]

Did you have ANY electrical experience prior to launching this (absolutely fascinating) project???

...

[turtle]

Not residential power. I was a weapons guy in the Navy so I learned basic electronics and electricity (BEE) but in my specific system I dealt with 15kVAC and around 600VDC in my RADARs. So I had a good baseline but had to learn so much about residential power. Then add solar on top of that.

Solar is really an area where I don't have to deal with much with my particular system. The panels feed DC to the inverters and they output AC. So everything I deal with is AC at 120/240V with 60Hz (or 66Hz when frequency shifting happens). In other words, normal North American electrical systems.