sunny boy inverter?

[Mike90250]

Just remember, when faking a Grid with a small inverter, if you solar array is producing 4,000 watts and you are only consuming 2,000 watts, something is going to happen.

Whatever happens, be sure you understand how your small inverter will respond if it suddenly sees 2000 watts coming into it. Will it shut off ? Will it try to frequency shift to control the larger inverter ? Will the larger inverter respond appropriately ? Will all the magic smoke inside be released ?

[solardreamer]

Nothing illegal for sure, i am talking if it is an apocolyspe scenario, so yes , it is essentially making a grid tie system into an off grid system was my question...is it cheaper to just purchase an off grid inverter and swap it and add batteries than to try to trick the existing inverter?

I doubt it would be cheaper to purchase an entirely separate off grid system of similar size to the grid tied system.

[solardreamer]

I hope you are not posting something that could be unsafe or illegal. Because a grid tie inverter (even with a secure power outlet) is not designed to provide full power if the grid is down.

Don't see anything illegal. It's all done while disconnected from grid. grid tied inverters work just fine with full power provided you have appropriate equipment for an island grid. Just look at Tesla Powerwall when it's disconnected from the utility grid.

[SunEagle]

Nothing illegal for sure, i am talking if it is an apocolyspe scenario, so yes , it is essentially making a grid tie system into an off grid system was my question...is it cheaper to just purchase an off grid inverter and swap it and add batteries than to try to trick the existing inverter?

You are correct. An off grid system will be safer and better then trying to change a grid tie system into working without the grid. Still if we are talking about an apocalypse scenario then IMO having power is not going to help you if you need medications that are no longer being made.

[mudhole]

Nothing illegal for sure, i am talking if it is an apocolyspe scenario, so yes , it is essentially making a grid tie system into an off grid system was my question...is it cheaper to just purchase an off grid inverter and swap it and add batteries than to try to trick the existing inverter?

[SunEagle]

Yes you can with any decent pure sine inverter but you need a system that can handle the max watts from all grid tied inverters in your system and you will need to manage excess PV production when your battery is full. For long term outage, it's essentially an off-grid scenario and since you already have a hybrid inverter it's likely more practical to use your inverter in off-grid mode with batteries and generator to charge the batteries when there is not enough PV production.

I hope you are not posting something that could be unsafe or illegal. Because a grid tie inverter (even with a secure power outlet) is not designed to provide full power if the grid is down.

[solardreamer]

thanks!, my scenario is power outage for a year or something, i also have generator and fuel source that would last "awhile", also i have the emergency outlet on this inverter, i think the max is 2kw output, but was curious how to "trick" the inverter to think it was still grid tie

Yes you can with any decent pure sine inverter but you need a system that can handle the max watts from all grid tied inverters in your system and you will need to manage excess PV production when your battery is full. For long term outage, it's essentially an off-grid scenario and since you already have a hybrid inverter it's likely more practical to use your inverter in off-grid mode with batteries and generator to charge the batteries when there is not enough PV production.

[SunEagle]

thanks!, my scenario is power outage for a year or something, i also have generator and fuel source that would last "awhile", also i have the emergency outlet on this inverter, i think the max is 2kw output, but was curious how to "trick" the inverter to think it was still grid tie

You can't trick the inverter. It is designed not to work totally unless it is connected to what the grid can provide. It sucks but that is for a safety reason.

[mudhole]

thanks!, my scenario is power outage for a year or something, i also have generator and fuel source that would last "awhile", also i have the emergency outlet on this inverter, i think the max is 2kw output, but was curious how to "trick" the inverter to think it was still grid tie

[oregon_phil]

Since you have SMA equipment, you can look at Sunny Boy Storage 6.0. This step to add AC couple the SMA battery inverter battery storage/backup power for catastrophes is much more involved than your DIY solar panel installation. My guess is that it would be at least twice the cost of your solar panel install.

Take a look at the SMA sunny boy storage brochure for backup power solutions. That will give you a start. If you really want to get serious, pretend your power is off for two weeks.

In my case, I bought a generator and transfer switch instead of using my SMA 7.7 inverter with battery inverter & batteries. My catastrophes typically have NO sun so solar power plus batteries wouldn't work.

[mudhole]

quick update and question, my solar array has been working GREAT, my question is this, I am a grid tie system, sunny boy 5.0-41, in the event of a catastrophe, can i AC couple this with simply a small solar array into a battery then into an inverter to input into the main inverter at 240 AC? (if the actual Power line input goes out?) if so is there a minimum amps needed?

[RShackleford]

i have the sunny boy 5.0 -41, i am confused with the installation book, is the multi function relay necessary to compete the install?

I came across this searching for info on the multi-function relay (MFR) and I'm pretty sure the answer to your question is "no".

I am curious though, how do people here normally use the MFR ? It looks to me like the "fault indication" mode is the one that is applicable to vanilla grid-tie installations. Apparently you supply your own power source (30vdc max) and bulb, and can use the MFR to either light the bulb up when there is trouble-free operation, or when there's a fault (depending upon which two of the three MFR terminals you use); the former makes more sense to me, because it'd also let you know if the battery, connection, or bulb is at fault (because the "trouble-free" bulb would not illuminate). But this mode seems silly, because surely the LED display and the network interface will let you know if there's a problem, right ?

[oregon_phil]

Did you check the event log after reboot to see if there is an Event Message? Good job on getting a replacement unit on the way only two days after failure.

[mudhole]

well it is just bad luck for me i guess, the dc cut off is bad, they are sending a complete new unit.

[mudhole]

we lost power last night for a short period, today i was looking at the inverter kw being produced and at mid day with full sun it was 3200, normally about 4100 kw , so i opened up the inverter and checked the voltage from the panels, much lower than they should have been, 220, 180 volts (roughly), so i decided to turn off and back on , turned off the AC breaker, disconnected the dc at the inverter, then reconnected the dc at the inverter and then turned on the AC breaker, (and also logged in , set up a password and all that stuff). when the reboot was over, i had zero dc input on the lcd, so i checked the dc voltage and it was now 280 and 245, which is what it should be for the panels strings of 8 and 7 panels.

so the panels are creating power, the dc disconnect is connected, the ac breaker is on, but i am not getting any Kw being created...during the reboot it goes through all the mppt strings attached, they all say 0 watts.

any thoughts???