Hello,

System : 5kW Sunsynk inverter, 2 x Pylontech US3000C, 4 x 460W panels (East-facing - MPPT1), 4 x 460W (West-facing - MPPT2)

I have a 3kW geyser connected to this AUX output, and I have set AUX LOAD ON to 100% and the AUX LOAD OFF to 80%.  I have set 'Solar Power' to 4000W .  I have noticed often when the batteries are 100% full, this AUX load is not active, and I'm hoping to understand which conditions could cause this behaviour.  This happens even when there is no load on the main "LOAD" output.

a) Could someone possibly explain what the "Solar Power" setting actually does?
b) Is this aux load functionality dependent on excess solar energy, or only on battery energy? 
c) If there is no load on the normal "LOAD" output, could the Sunsynk theoretically provide up to 5kW on this AUX port?

Thank you,

Ryan

I never played around with the AUX out on my 8kW Deye, but from what I read here and elsewhere it is a real b!tch to get to work properly.  My standard advise these days would be to put just about everything on essential, then manange actual use with discipline or timers, and keeping the AUX available for when we all inevitably wire in generators in future.

Another option is to wire the geyser as non-essential but after the CT coil - this way you get the same result as using the AUX port, i.e. use solar to power the geyser when sunshine and battery SOC allows.

Edited November 16, 20223 yr by Scubadude

2 hours ago, ryanb said:

System : 5kW Sunsynk inverter, 2 x Pylontech US3000C, 4 x 460W panels (East-facing - MPPT1), 4 x 460W (West-facing - MPPT2)

I have a 3kW geyser connected to this AUX output, and I have set AUX LOAD ON to 100% and the AUX LOAD OFF to 80%.  I have set 'Solar Power' to 4000W .  I have noticed often when the batteries are 100% full, this AUX load is not active, and I'm hoping to understand which conditions could cause this behaviour.  This happens even when there is no load on the main "LOAD" output.

a) Could someone possibly explain what the "Solar Power" setting actually does?
b) Is this aux load functionality dependent on excess solar energy, or only on battery energy? 
c) If there is no load on the normal "LOAD" output, could the Sunsynk theoretically provide up to 5kW on this AUX port?

If you've set the solar power setting to 4000W, but you've only got 8x460W panels attached (3680W max), then you'll never see the AUX activated. Nevermind the fact that you've got East and West-facing panels that are sub-optimal, but in total your panels can normally never generate 4000W.

The AUX depends on excess solar AND sufficient battery.

Try to see the logic as follows (and I'm not saying I'm 100% right, but just at least try it out):

1. The AUX functionality lies somewhere between essential load and non-essential load.

1.1 - If the grid goes down the non-essentials go down, but the essentials will still be feeding from the solar and battery systems.

1.2  The point of the AUX or Smart load is, if the grid goes down, you can still get useful power for some of your nice-to-have loads, but ONLY IF there is enough battery AND solar power available.

1.3 If you don't have enough of either solar or battery resource as per your settings, then the AUX will switch off, and only the essentials will remain, if the grid has gone down.

2. In your case I would try to set the AUX solar power setting to around 3000W (at least below your mid-day peak generation, whatever that is) and run the geyser on AUX at mid-day in the event that the grid goes down. It would have helped if you had more solar available, say 5000W peak, to give you a better chance, a longer time in the day when your solar production is well above the geyser load of 3000W. But in any case set the work mode for "zero export to CT" so that you can blend some solar power on most days if the grid is on, even if you don't get enough solar to run solely on AUX.

A bit long-winded, and partially based on Deye menu settings, but the ideas should be the same. Hope it makes sense. I'm not discussing the on/off scenario for when the grid is present, but menu option should exist also.

Edited November 16, 20223 yr by GreenFields
Disclaimer

Hi @GreenFields,

Many thanks for taking the time to respond in such detail - it really helped to clarify my understanding.

I have a few more comments and queries in response to your post (and all these questions pertain to scenarios while grid is not present) :

10 hours ago, GreenFields said:

If you've set the solar power setting to 4000W, but you've only got 8x460W panels attached (3680W max), then you'll never see the AUX activated

For clarity, is this "solar power" setting a minimum solar generation value? So in my case would the MPPTs need to be harvesting a minimum of 4000W before it considers switching power to the AUX port?  I always thought this was a maximum value, and hence my confusion.

10 hours ago, GreenFields said:

The point of the AUX or Smart load is, if the grid goes down, you can still get useful power for some of your nice-to-have loads, but ONLY IF there is enough battery AND solar power available.

So if the battery SOC is at 100% AND there is more than 3000W of PV generation, I would assume that the AUX port would be active.  Then, let's assume there was some temporary shading from a cloud.  Would you expect the AUX port to switch off during the shading?

I also found the attached document which was very helpful.

Best regards,

Ryan

 

 

 

AUX LOAD Sunsynk Explanation.pdf

7 hours ago, ryanb said:

For clarity, is this "solar power" setting a minimum solar generation value? So in my case would the MPPTs need to be harvesting a minimum of 4000W before it considers switching power to the AUX port?  I always thought this was a maximum value, and hence my confusion.

In relation to the AUX, yes, it is a minimum solar value.

7 hours ago, ryanb said:

So if the battery SOC is at 100% AND there is more than 3000W of PV generation, I would assume that the AUX port would be active.  Then, let's assume there was some temporary shading from a cloud.  Would you expect the AUX port to switch off during the shading?

You should check it out for yourself. I don't have mine connected, so I cannot speak from personal experience. But note that the AUX has a start and a stop battery level. Say you set it to come on if battery charge is 100%, it will deactivate once battery is depleted to a lower value, say 80%. That suggests that in the interest of stability it might not deactivate for every passing cloud, but rather draw from battery. I just don't know for sure.

On 2022/11/16 at 10:05 PM, ryanb said:

 

I also found the attached document which was very helpful.

AUX LOAD Sunsynk Explanation.pdf 387.35 kB · 10 downloads

Hi Ryan,

 

Thanks for posting this. Would love to hear if you got this working according to this explanation? I have been talking to my installer and he has recommended this approach for powering the geyser on excess PV.

21 minutes ago, domparry said:

Thanks for posting this. Would love to hear if you got this working according to this explanation? I have been talking to my installer and he has recommended this approach for powering the geyser on excess PV.

Hi Dom, yes it does work.  The advantage of powering the geyser on the output side of inverter, is that you can still heat your water during load shedding.

Hi all

Just wanted to check if I understand this correctly and if others have got it working correctly (specifically for a geyser)..

The AUX port will switch on/off depending on your settings when grid is not available.

When the grid is available, is the AUX always on using the grid plus spare PV and battery only when within the parameters? As opposed to being switched off when not within parameters.

Thanks

Maybe I can clarify my question a bit more..

I want to connect my 150l geyser with 3kw element to the aux/smart load of an 8kw SS/Deye inverter. Ideally, I want this to be powered from the grid at all times, EXCEPT when there is excess PV. In that case, it should use the PV. Let's also say I'm happy to use battery when battery is above 80%.

If I tick "on grid always on", set solar to 0, and battery on 100%, battery off 80%.. would this achieve what I'm looking for?

4 hours ago, solazzz said:

Maybe I can clarify my question a bit more..

I want to connect my 150l geyser with 3kw element to the aux/smart load of an 8kw SS/Deye inverter. Ideally, I want this to be powered from the grid at all times, EXCEPT when there is excess PV. In that case, it should use the PV. Let's also say I'm happy to use battery when battery is above 80%.

If I tick "on grid always on", set solar to 0, and battery on 100%, battery off 80%.. would this achieve what I'm looking for?

Have you managed to find a definitive answer to this? I too am wrestling with the idea of aux load vs non-essential (but connected to still use pv) vs connecting geyser to essential and just using a geyser timer. 
 

I would also like to use aux only when there’s enough pv. But say at night, and I want to switch geyser on for an hour, that it rather use the grid in that instance. 

The aux does not achieve what you're looking for..

Essential on geyser time could work better, depending on exact needs. And setting the inverter to use grid during the times that you set the geyser to run in the early AM or late PM.

On 2023/06/17 at 9:34 AM, solazzz said:

Maybe I can clarify my question a bit more..

I want to connect my 150l geyser with 3kw element to the aux/smart load of an 8kw SS/Deye inverter. Ideally, I want this to be powered from the grid at all times, EXCEPT when there is excess PV. In that case, it should use the PV. Let's also say I'm happy to use battery when battery is above 80%.

If I tick "on grid always on", set solar to 0, and battery on 100%, battery off 80%.. would this achieve what I'm looking for?

Depending on your settings PV can already be prioritised when there’s excess; though leaving the geyser on non-essentials and allowing the CT to handle this might be more suitable in your case. This is what I do; works great.

 

Take a look here regarding Aux/SmartLoad:

 

Edited July 12, 20232 yr by JayMardern

Hi guys, 

Just wondering re the aux load: i understand that this will work during loadshedding if the pv and SOC parameters are met. Does this however impact the kw's your inverter can push out eg if I have a 10kw setup (2 x 5kw inverters) and connect a geyser to the aux port, will the additional 2 or 3kw add to existing load and possibly trip the inverter? 

 

22 minutes ago, Solarmaxi said:

Hi guys, 

Just wondering re the aux load: i understand that this will work during loadshedding if the pv and SOC parameters are met. Does this however impact the kw's your inverter can push out eg if I have a 10kw setup (2 x 5kw inverters) and connect a geyser to the aux port, will the additional 2 or 3kw add to existing load and possibly trip the inverter? 

 

Yes, it does add to you essentials load.

14 minutes ago, PowerUser said:

Yes, it does add to you essentials load.

Thanx👍🏼

Not what I wanted to hear though 😕

On 2023/07/16 at 11:20 PM, PowerUser said:

Yes, it does add to you essentials load.

 

On 2023/07/16 at 11:36 PM, Solarmaxi said:

Thanx👍🏼

Not what I wanted to hear though 😕

We should submit a feature-request to Sunsynk to ask for an option to power off Aux automatically if it’s in use prior to tripping the inverter - and only trip if that doesn’t lower it back to a safe level!

@Solarmaxi How’s your experience with parallel inverters? Solid?

 

50 minutes ago, JayMardern said:

 

We should submit a feature-request to Sunsynk to ask for an option to power off Aux automatically if it’s in use prior to tripping the inverter - and only trip if that doesn’t lower it back to a safe level!

@Solarmaxi How’s your experience with parallel inverters? Solid?

 

Well, the inverter tripping is exactly some sort of protection against damaging the inverter. 
Now, this is like asking for another protection before the protection occurs (tripping).
I don’t even know how one submits features requests to SunSynk but I doubt any positive outcome will be achieved for such feature. 

On 2023/07/12 at 4:39 PM, JayMardern said:

though leaving the geyser on non-essentials and allowing the CT to handle this might be more suitable in your case. This is what I do; works great.

That would be my answer too, also how mine works.

The only real good uses of the AUX Out is when it is connected to something like underfloor heating  if you have other forms of heating, or as a secondary way of heating a geyser, for example if your geyser is primarily heated using hot water panels, and the element is connected to the AUX out to make use of any extra solar.

So just to clarify.

"AUX LOAD ON"  means put the aux loads on when then battery is above the set percentage. So setting the aux load on to 50% means it will only put the aux loads on when the battery state of charge is above 50%.

"AUX LOAD OFF" means put the aux load off when the battery is below the set percentage. So setting the aux load off to 50% means it will put the aux loads off when the battery state of charge is below 50%.

Also, aux loads will only be supplied with solar power, and not with power from the battery. I there a way that the aux load can use power from solar and battery and not from the grid?

The only way I found to have the aux load be supplied from battery power is to put the grid power off.

The two images below illustrates what happens when the grid is on or off.

38 minutes ago, Johannf said:

"AUX LOAD ON"  means put the aux loads on when then battery is above the set percentage. So setting the aux load on to 50% means it will only put the aux loads on when the battery state of charge is above 50%.

"AUX LOAD OFF" means put the aux load off when the battery is below the set percentage. So setting the aux load off to 50% means it will put the aux loads off when the battery state of charge is below 50%.

 

This is correct

 

38 minutes ago, Johannf said:

Also, aux loads will only be supplied with solar power, and not with power from the battery. I there a way that the aux load can use power from solar and battery and not from the grid?

The only way I found to have the aux load be supplied from battery power is to put the grid power off.

When grid is available, AUX follows the same supply rules as UPS, which (when on-grid), is governed mainly by the table in the System Mode-System1 screen. Think of AUX as just an extension of UPS, separated by a Relay/Switch, which is powered on/off according to the Aux screen settings. If you drop the battery percentages in System Mode-System1 and specify a maximum allowable battery power draw under 'Power' for the appropriate time-slots, the inverter will supply both Load and Aux from PV supplemented by battery, within those limits; and will only hit grid when those limits are reached. You can then use this to cycle the battery down during the day (I go all the way down to ~15%), and then target closer to 100% as sunset approaches.

Edited December 20, 20241 yr by JayMardern

On 2024/12/20 at 6:04 PM, Johannf said:

The two images below illustrates what happens when the grid is on or off.

Some battery is being used when the grid is available. 544 watts. What is controlling how much battery is used?

Edit: answer: the time of use settings for power for the current time slot, right?

Edited December 21, 20241 yr by Haysdb

On 2024/12/20 at 6:36 PM, JayMardern said:

This is correct

 

When grid is available, AUX follows the same supply rules as UPS, which (when on-grid), is governed mainly by the table in the System Mode-System1 screen. Think of AUX as just an extension of UPS, separated by a Relay/Switch, which is powered on/off according to the Aux screen settings. If you drop the battery percentages in System Mode-System1 and specify a maximum allowable battery power draw under 'Power' for the appropriate time-slots, the inverter will supply both Load and Aux from PV supplemented by battery, within those limits; and will only hit grid when those limits are reached. You can then use this to cycle the battery down during the day (I go all the way down to ~15%), and then target closer to 100% as sunset approaches.

This is what I’ve been thinking: I can’t prevent smart load from using battery when the grid is available but I can limit how much power can be drawn from battery for each time slot in time of use. During peak solar production hours I can force use of the grid by limiting battery power. 

I think of the smart load as semi-essential loads. They’re loads you’d like to keep running in case the power goes out but only up to a point. Like, if I can keep them running with 20% battery, ok, but if it costs more than that it’s not worth it.

I tried way too hard to use smart load for something it’s not suited for - an EVSE (EV charger). It finally seeped through my thick skull that’s just simply non-essential. I’ll never want to charge my EV from my home battery.

If smart load could provide ONLY excess solar at a trigger point of 1320 “excess” watts (6A), then it’d do what I want, but that’s not what it does.

Edited December 21, 20241 yr by Haysdb