Growatt Whole Home Backup (SYN-200) questions

[kscessnadriver]

I'm looking into an install using a one of Growatt's Whole Home Backup systems, due to a total lack of space in my pre-existing panelboard. Home is currently powered off of a Siemens 200A panelboard (with a 200A rated bus), 40 slot/40 circuit, which is completely full at the time. I had been contemplating moving some loads to a sub-panel, in order to free up slots for a potential backfed breaker, but by the time I screw around with that, coupled with a derate of the main breaker, I feel like installing the SYN-200 between my current meter and panelboard is probably the simplest method to get done what I want to do.

So, my question is, does anyone have any first hand experience in using one of these systems? It appears that the latest model allows for connection of up to 3 inverters into the system, which gives me room for down the road, should I choose to expand.

Initially I'd probably pair the SYN-200 with a MIN-11400TL-XH-US inverter. Any kind of battery install is something down the road quite a bit for me, maybe not at all

 

[1201]

Paging @MajicDiver

 

[kscessnadriver]

Paging @MajicDiver

I had a short conversation in a thread a few weeks ago about it, he didn't seem to know too terribly much about it, as it wasn't something he was interested in, from what I remember

 

[1201]

Can you do a line side tap instead? That's what I did with my system

 

[kscessnadriver]

Can you do a line side tap instead? That's what I did with my system

Probably an option, I'm just looking at it from the standpoint of why not use the SYN-200 for down the road capability. One of my biggest questions about the said whole house backup system is how do they use the generator input function. Is it only for battery charging or can it power the house in a grid down situation (with no backup batteries installed).

 

[MajicDiver]

Couple of comments:

1. I don’t know of any reason to use the SYN-200 unless you plan to install batteries and also anticipate you will want to normally be grid tied but want to automatically switch to off grid when grid goes down.

2. I avoid automatic stuff that adds significant failure points and/or complexity for people who may have to mess with it to get the lights back on in a pinch. I also don’t like the idea of a single box between me and the grid that my wife can’t figure out if something goes fubar when I’m gone. She would never figure out the SYN, she can handle opening 2 breakers and shutting one, all of which are easy to find and clearly labeled and instructions fit on less than a page in large print with pictures.

3. I personally prefer to be off grid, then if need to be on grid for some reason I open 2 breakers and and shut 1 breaker. My wife and sons have practiced. Again the syn would be confusing to many. They can easily get the house back up if something trips Inverters or something.

4. For us, and many houses, the utility feed is not in a location where you want to add anything you would like to keep cool (the auto transformer in the syn) or being an eye sore or take up limited space.

5. Before you buy a SYN, make sure the one you are getting actually supports 3 inverters- the first version only supported 1. I would not by it from SS for example because I don’t trust anything they say. I only buy panels and simple stuff from them when it’s cheapest. Renvu is an example of someone who will accurately tell you what you are getting, in my experience anyway. Santan also.

 

[1201]

Probably an option, I'm just looking at it from the standpoint of why not use the SYN-200 for down the road capability. One of my biggest questions about the said whole house backup system is how do they use the generator input function. Is it only for battery charging or can it power the house in a grid down situation (with no backup batteries installed).

Per the video I watched the generator will power the loads first and then charge the battery with any excess.

Also doing it this way won't you need quite a few of their batteries? They can get expensive. Whole house backup can get very expensive. I suggest consider doing it the right way which is a protected loads panel

 

[MajicDiver]

One of my biggest questions about the said whole house backup system is how do they use the generator input function. Is it only for battery charging or can it power the house in a grid down situation (with no backup batteries installed).

There are a couple of webinars on the Growatt USA YouTube channel that discuss this. One of them is below link. A little after 45 min I think,

 

[kscessnadriver]

Couple of comments:

1. I don’t know of any reason to use the SYN-200 unless you plan to install batteries and also anticipate you will want to normally be grid tied but want to automatically switch to off grid when grid goes down.

2. I avoid automatic stuff that adds significant failure points and/or complexity for people who may have to mess with it to get the lights back on in a pinch. I also don’t like the idea of a single box between me and the grid that my wife can’t figure out if something goes fubar when I’m gone. She would never figure out the SYN, she can handle opening 2 breakers and shutting one, all of which are easy to find and clearly labeled and instructions fit on less than a page in large print with pictures.

3. I personally prefer to be off grid, then if need to be on grid for some reason I open 2 breakers and and shut 1 breaker. My wife and sons have practiced. Again the syn would be confusing to many. They can easily get the house back up if something trips Inverters or something.

4. For us, and many houses, the utility feed is not in a location where you want to add anything you would like to keep cool (the auto transformer in the syn) or being an eye sore or take up limited space.

5. Before you buy a SYN, make sure the one you are getting actually supports 3 inverters- the first version only supported 1. I would not by it from SS for example because I don’t trust anything they say. I only buy panels and simple stuff from them when it’s cheapest. Renvu is an example of someone who will accurately tell you what you are getting, in my experience anyway. Santan also.

Honestly, that's exactly what I want, grid-tied, with a switch to off grid when it goes down. Points 2, 3 and 4 are all valid points and I totally understand where you're coming from. And yes, I would never buy it from SS, in fact, the only place I can find it in stock anywhere is at Renvu, which lists the part number in stock as the 3 inverter model. You can still find the single inverter model on their website, but it shows discontinued.

I like the idea of having batteries, its just not in the cards financially right now. A year or two from now, for sure its something I can make happen. Before I really started looking into solar, I was working on setting up a backfed breaker for my diesel generator, which obviously is a manual process. Using the ATS by Growatt would give me the ability to have it all automated (generator is capable of 2 wire start).

 

[kscessnadriver]

Per the video I watched the generator will power the loads first and then charge the battery with any excess.

Also doing it this way won't you need quite a few of their batteries? They can get expensive. Whole house backup can get very expensive. I suggest consider doing it the right way which is a protected loads panel

The loads I'd want to protect are the high draw loads, well pump, HVAC, etc... Its undoubtedly cheaper to have the diesel generator sitting at the house ready to go to backup the house than it is to buy enough batteries to run the house.

 

[1201]

The loads I'd want to protect are the high draw loads, well pump, HVAC, etc... Its undoubtedly cheaper to have the diesel generator sitting at the house ready to go to backup the house than it is to buy enough batteries to run the house

Oh so you are not even after a battery? How much is the syn 200? I saw something online and it looked like it's around $2000?

Sounds to me like an expensive way to avoid putting in a $60 subpanel

 

[kscessnadriver]

Oh so you are not even after a battery? How much is the syn 200? I saw something online and it looked like it's around $2000?

Sounds to me like an expensive way to avoid putting in a $60 subpanel

How does a sub-panel help me; I'm still limited on how much I can backfeed into my main panel, one way or another. The only other real option I see is modifying my current service into a service disconnect just after the meter (with the N/G bond), and then having 2 individual panels fed by that. By the time I pay an electrician (I'm not willing to play with stuff on the otherside of the main shutoff, requiring PoCo shutdown to accomplish) to do that, I'm probably nearly at the cost of the SYN-200. SYN-200 is about $1800, so coupled with a MIN-11400 inverter, I'm still way cheaper than a EG4 18kPV or a Solark 15K, which is what a SYN-200 + MIN-11400 basically emulates. Batteries aren't on the table right now, but within a year or two they likely will be, which is why I'm debating future proofing this install.

 

[1201]

How does a sub-panel help me; I'm still limited on how much I can backfeed into my main panel, one way or another. The only other real option I see is modifying my current service into a service disconnect just after the meter (with the N/G bond), and then having 2 individual panels fed by that. By the time I pay an electrician (I'm not willing to play with stuff on the otherside of the main shutoff, requiring PoCo shutdown to accomplish) to do that, I'm probably nearly at the cost of the SYN-200. SYN-200 is about $1800, so coupled with a MIN-11400 inverter, I'm still way cheaper than a EG4 18kPV or a Solark 15K, which is what a SYN-200 + MIN-11400 basically emulates. Batteries aren't on the table right now, but within a year or two they likely will be, which is why I'm debating future proofing this install.

Ok Im trying to understand- when you say backfeed, do you mean from a generator or from a pv inverter? What's is the limitation?

If you move two circuits to a 30 dollar subpanel now you have space in main panel for a generator breaker with interlock no?

 

[kscessnadriver]

Ok Im trying to understand- when you say backfeed, do you mean from a generator or from a pv inverter? What's is the limitation?

If you move two circuits to a 30 dollar subpanel now you have space in main panel for a generator breaker with interlock no?

Sorry, I wasn't clear. I've got a generator backfeed breaker already installed with an interlock, no issues there. I'm limited in solar backfeed potential on the panel. 200A panel, 200A main breaker, 200A bus. Even derating the main to 175A, I'm not going to be able to backfeed solar into the panel more than with a 65A breaker. I'm looking at potentially doing as much as 20kW of solar, so I need the headroom to backfeed it to grid-tie.

 

[zanydroid]

Sorry, I wasn't clear. I've got a generator backfeed breaker already installed with an interlock, no issues there. I'm limited in solar backfeed potential on the panel. 200A panel, 200A main breaker, 200A bus. Even derating the main to 175A, I'm not going to be able to backfeed solar into the panel more than with a 65A breaker. I'm looking at potentially doing as much as 20kW of solar, so I need the headroom to backfeed it to grid-tie.

There are a lot of ways to achieve this. I’m backfeeding 20kW through a 40 year old 100A MSP

EDIT: I might be missing something but I think refactoring your MSP to achieve this is the same difficulty as DIYing a SYN-200 behind that MSP.

 

[kscessnadriver]

There are a lot of ways to achieve this. I’m backfeeding 20kW through a 40 year old 100A MSP

Are you feeding onto the panel or into a line side tap?

 

[zanydroid]

My MSP has a single breaker that is a 100A feeder. This goes into a 225A bus rating distribution subpanel (new install to support solar and electrification)

I have 100A of solar breakers feeding into this.

IOW I use the sum of breakers rule on MSP and 100%/120% rule on the subpanel

EDIT: this is known some places as Hawaiian Tie In

 

[zanydroid]

And when you say line side tap, do you mean line side of main disconnect (typical meaning, this requires POCO approval), or between main disconnect and that 200A subpanel (this does not require POCO approval, there are multiple ways to configure the tap into the feeder, best way depends on your existing conditions).

(And note many combos meter main are not convertible to subpanel)

 

[1201]

Sorry, I wasn't clear. I've got a generator backfeed breaker already installed with an interlock, no issues there. I'm limited in solar backfeed potential on the panel. 200A panel, 200A main breaker, 200A bus. Even derating the main to 175A, I'm not going to be able to backfeed solar into the panel more than with a 65A breaker. I'm looking at potentially doing as much as 20kW of solar, so I need the headroom to backfeed it to grid-tie.

Ok copy that. That makes things clearer. So help me understand- you have 20kw feeding into the syn 200, that will feed up to 20kw into the main panel correct? Or are you going to place the syn between the grid and main panel? Sounds like it would still be a lot of work and electrician expense to place it between the main panel and grid, or you still have a 20kw current source feeding the main panel and would still not be allowed.


Heck I don't believe you could even feed 20kw through a line side tap. I know my taps have a limit of 70a.

Btw, a syn200 + growatt 11kw is not similar at all imo to a solark 15k. It's not battery agnostic and the DC converter in the battery has a limit of 5kw ,I believe ,unless you buy multiples and that's $$$.

You should look into the new growatt that's coming out next month

 

[zanydroid]

Does the SYN-200 have the super janky transfer behavior of the cheaper growatt Autotransformer + ATS combo, or does it properly sync to grid before switching off EPS?