Help me Install 3 EG4 Mini Split Solar Heat Pumps

[MrM1]

Weather here has been a drag on the panel install.

I continue to do the in-house under roof upgrades and anything else that can be done between the multiple times a day showers we have been getting the past 3 weeks.

Looking at the forecast, it seems I may have a window this week to install the 19 panels for the 3 AC's. But the time I actually get them installed, there will be nothing left to do but attach the MC4 connectors. Everything else is nearly done, tidied up and properly installed. When it's all done, it will be really good. So hoping for this week.

 

[Plum Crazy Rob]

The things you find on Alibaba. Did run across this picture of innards, MPPT upper left..

 

[Plum Crazy Rob]

Weather here has been a drag on the panel install.

That's OK. I have these new units here collecting dust for awhile, been off to Colorado some of June / will be most of July then a trip to CANADA ??

Which reminds me...for those that don't know, warranty registration for these is via the EG4 website if you didn't know - wasn't really paperwork with the units for that...

 

[RDuke]

Oh I did not know about the registration. I will have to take a look. I am dragging my feet about getting started on mine. I guess I will work on the grid side and get that going first. The heat and humidity has gone up in the southeast so it is pretty rough working outside now, so I am mostly doing research. I am wondering if anyone has gotten or plans to get their installation inspected for compliance. I am pretty sure I can install my safely, but I still have my doubts about what the inspectors want to see. The manual says you are supposed to have DC ground fault equipment installed. I have only found a couple of ways to do that. I even contacted EG4 support asking them for recommended equipment for it, but they declined to recommend anything. They did send me a document stating they are compliant with UL 1741 dated 16 Sept 2020. That document covers equipment for use with distributed energy resources. NEC 690.41 B2 says I need to have DC ground fault, and that the current carrying conductors (plural) have to be disconnected when faulted. 690.41 B3 says you have to have some kind of indicator of the fault, so I am not sure if I can just have a tripped breaker for an indicator (Midnight Solar GF breaker). They make reference to a number of examples like receipt of web based notification as an acceptable example. At least one good thing is that if you do not put it on your roof, you do not have to worry about rapid shutdown compliance, So I may put my panels on my old above ground pool deck which is very sturdy. We will see. There is a lot to learn that is for sure. So I am watching this thread to try to pick up as much as I can from you all.

 

[MrM1]

Oh I did not know about the registration. I will have to take a look. I am dragging my feet about getting started on mine. I guess I will work on the grid side and get that going first. The heat and humidity has gone up in the southeast so it is pretty rough working outside now, so I am mostly doing research. I am wondering if anyone has gotten or plans to get their installation inspected for compliance. I am pretty sure I can install my safely, but I still have my doubts about what the inspectors want to see. The manual says you are supposed to have DC ground fault equipment installed. I have only found a couple of ways to do that. I even contacted EG4 support asking them for recommended equipment for it, but they declined to recommend anything. They did send me a document stating they are compliant with UL 1741 dated 16 Sept 2020. That document covers equipment for use with distributed energy resources. NEC 690.41 B2 says I need to have DC ground fault, and that the current carrying conductors (plural) have to be disconnected when faulted. 690.41 B3 says you have to have some kind of indicator of the fault, so I am not sure if I can just have a tripped breaker for an indicator (Midnight Solar GF breaker). They make reference to a number of examples like receipt of web based notification as an acceptable example. At least one good thing is that if you do not put it on your roof, you do not have to worry about rapid shutdown compliance, So I may put my panels on my old above ground pool deck which is very sturdy. We will see. There is a lot to learn that is for sure. So I am watching this thread to try to pick up as much as I can from you all.

Ummmm yikes?!?

 

[justgary]

I am not sure if I can just have a tripped breaker for an indicator (Midnight Solar GF breaker).

A tripped breaker is a great indication of a tripped breaker, whether it is due to GF or overcurrent. It makes sense to me that it should count.

 

[RDuke]

I was originally going to put the panels on my roof, but I am still considering a shade trellis. If the trellis is attached to my house, I have to assume it falls under being on my home which technically sounds like I have to have arc fault and rapid shut down - 690.11 and 690.12 in the 2020 NEC which my state is on. Ground mount does away with some requirements it seems. I was just kind of shocked (no pun) that there were not many standalone arc fault and ground fault products. I assume the detection is typically built into modern inverters whether grid tie or off grid use.

I want it to be as safe as possible because I already had one fire started by solar. In 2017 a $5 solar LED flower overcharged the tiny battery, and it exploded setting my lawn on fire. Fortunately my wife saw it, and I put it out before it burned my house down. Talk about yikes.

 

[MrM1]

And for me ... it begins.

After going up on my roof a month ago, and discovering a whole host of problems that needed to be addressed. I finally got all of the issues taken care of, and Got all the roof mounts and rails installed.

The first part of the solar upgrade was to increase the size of my Battery Charging array to help keep my LFP bank charged. With the Added ACs x3 running off the inverter it was difficult to get enough power to charge the batteries and run the ACs (but that gets largely mitigated once the AC solar arrays are installed)

So here is the Charging Array Upgrade:
- began with 9 285w panels 5 years ago
- Added 9 more 290w panels and a 2nd Midnite Solar Classic 150 Charger 18 months ago
- This gave me a total of 6 strings configured 3s each
- Last week added 2 more strings of 3s (6 panels)
- So now I have 3100 watts of panels going into EACH Classic 150 for a total of 6200 watts of charging power

The Original 9 are closest in the pic, the next 9 are beside that, and the new 6 are on the bottom




This is all just for off grid Charging and AC support to the DC side of the EG4 mini splits. I will now run all EG4s in contentious AC limit mode from the Inverter. This will keep the MPPTs in the mini splits from going to sleep in the day if it gets too cloudy.

 

[MrM1]

And finally ... After several weeks of roof repairs and additional rack installing, the 19 mini split panels started to go up yesterday

The Rack install For all 19 mini split panels
Every thing is South Facing. Pic was taken at 5:30pm EST. Mostly Still Full Sun on all 19



These 14 are for the two 24k units. 7 to each 24k


These 5 are for the 12k unit.



Yesterday we got the first 5 to the 12k mini split done.



And Today ... We make power, all-be-it Limited as the sky is pretty cloudy.
Still not to bad at 9:30am

 

[Plum Crazy Rob]

I am wondering if anyone has gotten or plans to get their installation inspected for compliance

I think we are all trying to be safe, but it doesn't appear any are inspected. I WOULD like to learn "officially " what is required. I say quote-unquote because it's become clear from inverter-array installs "your inspector may vary". As well as differences on what NEC code your AHJ has adopted.??

Also keep in mind manual clearly came from Australia, see refs to AS-NZ codes blah blah blah, etc.

 

[Plum Crazy Rob]

the 24 mini split panels started to go up yesterday

This is exciting!!

 

[MrM1]

This is exciting!!

Miss Type. Sadly it's only 19 panels. But it will give me a total of 43 for all charging and mini split powering

 

[MrM1]

Good news is, i just saw 825 watts coming in from the 12k array when I turned it down to 66F at 9:45am. That's Almost full needed power for the 12k before 10am

 

[Plum Crazy Rob]

I wish I knew enough about roof-mount to make a more intelligent comment. However I know some about the Solar mini split and the Texas heat is here today, 104 predicted ??

Hit 100 last week with 110 heat index and no problem, still ice box conditions under area covered with mini split

 

[MrM1]

I wish I knew enough about roof-mount to make a more intelligent comment.

Am I doing something that looks Unintelligent?

 

[MrM1]

Oh My ... here is a link to some really good and scary info out of Australia on DC Arch faults. Apparently anything over 80v dc is susceptible and there does not seem to be a good solution for these EG4 mini splits, especially if you roof top mount them. The needed operational voltage is just too high. What is anyone's take on this? How would you implement protection?

It does not seem that rapid shut down would help much. Turning off the mini split system or even an arch fault breaker at the mini split or at the roof entry point would not help on the roof once the arch starts.

What could you do to protect from this?

Solar fires

DC arc faults on solar PV systems have been identified as the root cause of over 250 domestic and commercial building fires in Australia

www.acsolarwarehouse.com

 

[Plum Crazy Rob]

Oh My ... here is a link to some really good and scary info out of Australia on DC Arc faults

I saw that link previously. Was there a main board discussion?? There should (or could?) be?? With the trend towards higher and higher voltage mppts...

(*reads article*) Only solution really microinverters and DC optimizers, would at least confine a fault to presumably a single panel - internal fault / short etc. Note PANELS seem to be trending towards higher voltages as well...

PS happily ground mounted here...However of course I have a DC disconnect mounted on my siding, etc

 

[Plum Crazy Rob]

Good news is, i just saw 825 watts coming in from the 12k array when I turned it down to 66F at 9:45am

Since you have an entire Solar system that can power these (or ordinary non-Solar units) already , I find it INTERESTING that you are as excited as I am to see mine running on Solar!! Lol ?

 

[MrM1]

Since you have an entire Solar system that can power these (or ordinary non-Solar units) already ...

But there is is my problem ... My Lil' Solar system CAN'T actually power all 3 EG4s AND the rest of my loads. It's only a 3800w inverter and my loads with out the EG4s gets up into 2800 watts. so with the EG4s I exceed this.

This is why I will run the on the inverter, but in AC Limit mode, so I do not over load the inverter. And this is why I went with AC/DC mini splits in the first place, to avoid an entire Inverter / Charge Controller upgrade. If was cheaper to add the AC/DC ACs than to install a much larger inverter.

 

[Zwy]

Oh My ... here is a link to some really good and scary info out of Australia on DC Arch faults. Apparently anything over 80v dc is susceptible and there does not seem to be a good solution for these EG4 mini splits, especially if you roof top mount them. The needed operational voltage is just too high. What is anyone's take on this? How would you implement protection?

Someone is painting with a broad brush to sell micro inverters in that link.

If you look at many of those photos, the majority are loose connection issues. Second place are components of questionable quality such as the isolators appear to be Chinese made clones/copies of the IMO. Another component issue is MC4 connectors, unless you have connectors from all the same manufacturer, there is a risk of a substandard connection, this really needs some standardization. Third is water penetration.

The best way to stop an arc fault is not create a condition where one could exist. That means using ferrules on multi strand wire, ensuring proper tightening of connections. Not sourcing cheaper components and using components that are compatible. Ensuring there isn't water penetration by using proper weather heads, drip loops and sealing of compartments/using properly outdoor rated components.

Fires occur in AC service panels/systems if proper methods aren't employed to prevent water intrusion, DC isn't different.