If paralleling two single-phase Sunsynk/Deye inverters, does anyone know how the wiring is supposed to look for the Aux (or SmartLoad) port, for output purposes?

Is the full combined inverter output available to Aux; or is it limited to the maximum for a single inverter?

Assuming that Aux is just a relay-separated extension of Load, I'd assume it's combined - but I can't find any confirmation.

The Sunsynk Youtube channel seems to indicate that it can be done (https://www.youtube.com/watch?v=NUZOCu15GMU and https://www.youtube.com/watch?v=eWzLFR-s4K4 mention using a "single breaker" for Aux when paralleling) but don't go into further detail.

Other documentation ( https://www.sunsynk.org/post/copy-of-paralleling-inverters ) does indicate that the port can't be used as a generator input in this configuration but output seems to be OK.

Like all things Aux, there's a dearth of detail on how it actually works; I'm hoping someone who's done it before can chime in!

I think one must look at the logic of the OEM , when you think about the capabilities of such a parallel combination. When you parallel let's say 2 x 5kW machines you effectively have a single 10kW machine at the end of it. Changing settings in the master or slaves Work mode timer changes both. The Load & Grid Breakers are in parallel. Surely the same has to be said about the AUX port. The inverter seize to be individual 5kW machines & assume the role of 1 x 10kW powerplant. Meaning also that they will share the AUX load or even share the PV input if a said mictoinverter is added. 

 

15 hours ago, Steve87 said:

I think one must look at the logic of the OEM , when you think about the capabilities of such a parallel combination. When you parallel let's say 2 x 5kW machines you effectively have a single 10kW machine at the end of it. Changing settings in the master or slaves Work mode timer changes both. The Load & Grid Breakers are in parallel. Surely the same has to be said about the AUX port. The inverter seize to be individual 5kW machines & assume the role of 1 x 10kW powerplant. Meaning also that they will share the AUX load or even share the PV input if a said mictoinverter is added. 

 

Yeah I feel like this should be the case,

But it's not entirely that simple unfortunately: there isn't perfect feature parity in single-unit vs parallel mode on the Aux port; that link in my original post to their own documentation indicates:

Quote

Do not connect the 'AUX/Gen' input in parallel. This input can be used for Aux / Smart Load if required, but it is generally better not to use.

So we know we can't safely use it as an input anymore once we're running multiples; and using it as an output is listed as "generally better not to use"

Thus the reason I'm asking if anyone's actually done this as an output on single-phase and had success (and if there're any caveats myself and others should be aware of before pulling the trigger... i.e., what on earth does "generally better not to use" mean!) 😀

If you think it will blow up then observe good judgement & live without it. 

4 hours ago, JayMardern said:

Yeah I feel like this should be the case,

But it's not entirely that simple unfortunately: there isn't perfect feature parity in single-unit vs parallel mode on the Aux port; that link in my original post to their own documentation indicates:

So we know we can't safely use it as an input anymore once we're running multiples; and using it as an output is listed as "generally better not to use"

Thus the reason I'm asking if anyone's actually done this as an output on single-phase and had success (and if there're any caveats myself and others should be aware of before pulling the trigger... i.e., what on earth does "generally better not to use" mean!) 😀

It could also just mean unstable and then indicate rather not to do it. Not as serious as a blow up is my guess. 

I specifically emailed Deye about using the Aux port in parallel for a generator input and they said you can do this. 

I have since connected multiple large diesel gensets to paralleled Sunsynk 8 and 12kw inverters without issue. In fact, the inverters won't use the power from the generator if it is only connected to one inverter input in a parallel configuration.

I can't comment on the paralleled aux output but have seen the recommendation not to do so. So as a potential workaround if you want to use the aux as an output (which is basically on the load side anyway), is to use the aux port from one inverter as a contactor signal only to leverage the logic. Thus, you use aux port to switch on/off the contactor connected after the parallelel load breaker to power your "smart" loads.

Edited September 8, 20232 yr by AlexTZA

 

I specifically emailed Deye about using the Aux port in parallel for a generator input and they said you can do this. 

I have since connected multiple large diesel gensets to paralleled Sunsynk 8 and 12kw inverters without issue. In fact, the inverters won't use the power from the generator if it is only connected to one inverter input in a parallel configuration.

I can't comment on the paralleled aux output but have seen the recommendation not to do so. So as a potential workaround if you want to use the aux as an output (which is basically on the load side anyway), is to use the aux port from one inverter as a contactor signal only to leverage the logic. Thus, you use aux port to switch on/off the contactor connected after the parallelel load breaker to power your "smart" loads.

Thank you!

 

Using it just as a 230V Boolean signal (for an external contactor) is a great option assuming that it works at all. I wonder if newer software has sorted this out since on the Sunsynk link above they specifically say you can’t use it as an input; yet you’ve seen it work fine.

Could you DM me the email address you used to contact them regarding this? I’ll drop them a mail regarding using it as an output and share the feedback here.

@JayMardern - I've found its best to speak to Deye if there are any technical questions as I've found Sunsynk support to be somewhat...limited, especially around topics that are not clear. 

I usually send an email to [email protected] which is the main support email address listed on their website. It sometimes takes them a while to respond.

 

@JayMardern - I've found its best to speak to Deye if there are any technical questions as I've found Sunsynk support to be somewhat...limited, especially around topics that are not clear. 

I usually send an email to [email protected] which is the main support email address listed on their website. It sometimes takes them a while to respond.

Yup that’s precisely why I asked for Deye not SS’s contact. Because if their support is anything like Keith’s videos, then we can’t expect too much 😉

I love the hardware, love the firmware/software skin, adore the portal - but their documentation, support and videos are positively average.

 

I’ll revert back when I hear back; thanks again!

Great, looking forward to the feedback!

From Deye's service desk (this was quick!):

 

It's ok to use, no problem.And gen ports are paralleled,outputs maximun 10kw.

 

I'm assuming the documentation is out of date (likely there were firmware issues at some point that have since been solved)... this would also explain why using it as an input seems to be working OK now.

 

But looks like we're good to go! From their reply, we can see that the gen port (which is the Aux port) would be paralleled; and the maximuim allowable output would be the combined output of both inverters (5kW + 5kW in my example) - exactly as we'd expect. Fantastic news.

 

As load shedding gets worse and further impacts solar water-heating time, I do believe that it'll start making sense for pretty-much everyone using an electric geyser to move them from non-essentials (which are still powered by excess solar on these units) to Aux instead, to allow solar-based heating in the absence of the grid with a level of protection for the battery level that Aux offers.

This even makes it possible to do heating in phases when there's insufficient PV to do it directly; since with an appropriate battery level set, a 3-hour heat could be split over 6 hours that take place automatically as the battery level rises. (So for example, a battery range of 70%-90% would have the port activate at 90%, heat the geyser down to 70%, switch off, and then repeat again when the battery gets back up to 90%). It'd take longer but the fact that it's even possible - without depleting the battery completely - is great news.

Thank you for the information. 

Have anyone connected a paralleled Aux output on 2 x inverters connected in parallel with success? 

I have the Aux load on a single Sunsynk 5kW running with great success, about to also use it on 2 x 5kW connected in parallel, would just like some feedback from someone who have already done it successfully. 

Edited January 4, 20242 yr by Bushbaby

2 hours ago, Bushbaby said:

Thank you for the information. 

Have anyone connected a paralleled Aux output on 2 x inverters connected in parallel with success? 

I have the Aux load on a single Sunsynk 5kW running with great success, about to also use it on 2 x 5kW connected in parallel, would just like some feedback from someone who have already done it successfully. 

5 hours ago, Bushbaby said:

Thank you for the information. 

Have anyone connected a paralleled Aux output on 2 x inverters connected in parallel with success? 

I have the Aux load on a single Sunsynk 5kW running with great success, about to also use it on 2 x 5kW connected in parallel, would just like some feedback from someone who have already done it successfully. 

I posted in another thread that has the OP successfully running Aux/SmartLoad on a pair of paralleled 5kW’s:

Seemed to be working fine.

I also asked my installer before ordering a second 5kW Sunsynk myself (I’m about to do the same as you!); he confirmed Aux in parallel works on the Sunsynks as expected and he hasn’t run into any issues doing so.
 

On Videos They Say Its Not Advisable But I Have Installed A Few Units With The Aux Port Paralleled And Never Had An Issue 

 

I've been trying to get an answer on this for ages and see somebody actually do it before I commit to it myself.

Just found this video pop up on YouTube. He's done it successfully by the looks of it.

https://youtu.be/A14GhJvw8Dk

Might help someone else......

On 2024/07/18 at 11:39 AM, WTW said:

I've been trying to get an answer on this for ages and see somebody actually do it before I commit to it myself.

Just found this video pop up on YouTube. He's done it successfully by the looks of it.

https://youtu.be/A14GhJvw8Dk

Might help someone else......

I've done it my side,

The OEM (it's Deye in the case of the Sunsynk models) has confirmed that it's OK, I included their email to this effect in my post above. It would probably be a good idea to be on recent-ish inverter firmware, though.

We've been running parallel'ed Aux since February, and I've stress-tested with up to 8.5kW worth of load (both geysers on simultaneously - doesn't happen in normal use just during stress-testing - plus stove) via Aux on my 10kW system (2 x 5kW inverters). The Aux maximum is the same as regular Load; so as long as Aux + Load is under the inverter/battery limit, you're in business.

It works perfectly, and - having both geysers and the stove wired to Aux gave us hot water and hot food during our last extended outage. We used the Aux battery cut-offs to protect battery SOC (it allowed us to only heat the geysers/run the stove once the battery was full so that we had a full battery going into the evening while the grid was down).

The family was very happy to have a hot food with hot water whilst waiting for City Power to fix the fault. And on a cloudy day, we heated just the one geyser instead.

Edited July 25, 20241 yr by JayMardern

That's great to hear, thanks.

After watching the video I mentioned, I went out and rigged up an aux load in parallel to run my immersion/geyser, and as you say, it works perfectly.

It's comforting to hear that you've stress tested it like that, and that you've had it running for so long now. Thanks for the reply. 👍