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Sunsynk aux load for geyser


Craigm
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I have been running my system for a few months now.

- 8kW Sunsynk inverter

-5kW array

- 2x 3.5kWh pylontechs

 

A generator changeover switch was installed in the house already, so I just had this routed into the Aux port. In hindsight, not worth it as I haven't needed to run it at all and I wouldn't mind taking it out if necessary.

I also have a geyserwise controlling the electric geyser (3kW). Geyser is connected to the non-essential side of the DB.

 

We've had some power cuts over the last few weeks which left me with cold water at kid bath time (wife was not impressed).  With loadshedding again this week, I run the risk of not having hot water if the grid is down when my geyser is scheduled to run. Yet I "throw away" plenty of power that I could be pumping into the geyser.

I have done some reading and consulted the manual, and it seems like the aux output might do the trick.  However, I am not sure how to go about setting it up wrt the changeover switch.  Is there a simple DIY "smart" solution, that will changeover depending on conditions? Or change it manually, but remotely?  For example, I want to heat the geyser from the sun early afternoon (or when batteries are charged and load is less than generation), but from the grid in the early hours of the morning (or when cloudy), but I don't want to have to physically flip a switch.  It must be "wife friendly" for when I am not home.

 

Any ideas on how to approach this or what products to look at? Wifi enabled (e.g. Sonoff type device) would be ideal, but I am not a sparky or a programmer, so I need something simple.

 

Cheers

Craig

Aux load diagram.PNG

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Hi @Craigm

I do not have my Sunsynk installed yet - so I do not have any practical experience. But from what I have been reading, the Sunsynk should (with the right settings and the CT coil in the right place) push excess PV to the non-essential loads (not on Aux). That way, you should not be 'wasting' any PV.

Where is your CT coil installed?

To my understanding (and the way I am planning my install) is to put the geyser on the non-essential side of the DB but after the CT coil. With the settings 'Zero Export' and 'Limit to Load Only' enabled, any excess PV should then be used for loads on the non-essential side. And you can use a Sonoff/GeyserWise to control what time the geyser should run 

I have to admit that I do not know what happens if no grid is available in this situation (but excess PV exceeds non-essential load)?

Maybe someone running the Sunsynk can confirm?

 

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1 hour ago, wolfandy said:

Hi @Craigm

I do not have my Sunsynk installed yet - so I do not have any practical experience. But from what I have been reading, the Sunsynk should (with the right settings and the CT coil in the right place) push excess PV to the non-essential loads (not on Aux). That way, you should not be 'wasting' any PV.

 

Correct. But when the grid is down, the generation is limited to the consumption on the essential load only, which means 4kW generation potential pushing out only 300W and the rest being "wasted".  When the grid is down, it only powers the essential circuits.

My question is specifically around the scenario when the grid is down. I currently run the geyser from 12:00 and 14:00, whether there is sufficient PV or not (pull from grid if there's a shortfall). But if the grid is down during this time, cold shower for wife and cold shoulder for me!

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1 hour ago, Achmat said:

It's all automatic and based on settings on the inverter. 

It will switch the aux output on or off depending on available pv or minimum battery. 

@Tariqhas his geyser on the aux and could shed some light. 

Thanks Achmat. I understand that for the daytime run. But how does the nighttime run work? I dont want to run batteries down to power the geyser, I'd rather pull from the grid. If that's possible.

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6 minutes ago, Craigm said:

cold shower for wife and cold shoulder for me!

Something definitely to avoid 😜

7 minutes ago, Craigm said:

My question is specifically around the scenario when the grid is down.

Then I believe Aux is your only option - but do not know enough how that behaves during nighttime (or only cloudy days - have heard of people ending up with cold water on cloudy days with their geyser on Aux)

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1 hour ago, Craigm said:

Thanks Achmat. I understand that for the daytime run. But how does the nighttime run work? I dont want to run batteries down to power the geyser, I'd rather pull from the grid. If that's possible.

You can set the aux to only run when batteries are above a certain SOC if the grid is down. 

If the grid is available it will use from the grid first before doing into batteries. 

 

Grid down scenario 

Daytime pv goes to load, aux and batteries 

Nighttime batteries powers load then optionally can send power to aux. Its batteries drop below a certain thrusting then only loads will get power. 

 

Grid available 

Daytime pv goes to loads, aux and batteries. If allowed, excess can feed back to the grid side. Overcast will be the same as nighttime below. 

Nighttime batteries powers loads then aux until set SOC is reached. This can be 100% then batteries will never be used for aux loads. Aux loads will then get power from the grid. 

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 Have removed the geyser from AUX, as the system does not work as designed anyway. Hot water is needed, whether it is a sunny day or not, now I have the geyser ( 2 kW element, set to 70 degrees) on the non-essentials circuit,connected via a CBI Astute WiFi switch, set to come on at 9:45 am, when there is about 2000 Watts of pv power available, and I keep the SOC at 65 %, so that battery does not get depleted if there is no sun, then uses the grid

  The nice thing with the CBI Astute switch I can change the timer settings and/or switch on/off the geyser, also, it is rated for 30 amps, mounts right in your db, no messing with a Sonoff AND a contacter

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First I connected the geyser to AUX, in the morning when both conditions were met, soc and pv, the system would switch on, then if AUX switched off due to pv or soc dropping below the limits, so far so good, but then if the limits were re established, AUX will not switch on again for the day. Thinking the geyser not coming on for the second time on the same day was due to the thermostat, so I connected AUX to the pool pump and it would not worked as designed and could not get any clear answers from Keith Sunsynk.

 

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Smartload starts when the power consumption in the house exceeds the threshold in the settings.

 

On my set up I've set it to go on at 90%, turn off at 60%, if the power consumption exceeds 1200 watts. This gets the geyser running for a full cycle at least once, or maybe more per day if there are some other power drawing loads running.

 

This means I would need to, at the very least temporarily, run the kettle or something to get the load past the 1200 watts so the smartload starts.

 

I find it heats the water up sufficiently during the day for my needs like this.

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This thread has been a proper rollercoaster for me...

I've been wanting to run my geyser off the AUX port on my (still to be purchased) system, but if it doesn't work, then I'm thinking of going the Axpert route... WAY cheaper... 

BUT, if it does work.... 🙄

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On 2021/05/18 at 6:56 PM, excitedphoton said:

Smartload starts when the power consumption in the house exceeds the threshold in the settings.

 

On my set up I've set it to go on at 90%, turn off at 60%, if the power consumption exceeds 1200 watts. This gets the geyser running for a full cycle at least once, or maybe more per day if there are some other power drawing loads running.

 

This means I would need to, at the very least temporarily, run the kettle or something to get the load past the 1200 watts so the smartload starts.

 

I find it heats the water up sufficiently during the day for my needs like this.

Hi do you mind explaining this a bit further. I have my geyser on aux as well but I have only seen it once pushing power to aux. So on the aux screen the power you specify is minimum load on the house so that aux is activated?

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I'm planning a similar set up to @Craigm, except I have a solar geyser.

Was also planning on setting up on the non essential side, but then have a problem if no grid.

What would be ideal is if I could have the pump and geyserwise controller on essential, and the element on non essential. This way atleast I will have hot water at night if no power in the day. Not sure if thats possible though?

Would still have an issue in the morning though.

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20 minutes ago, Mark M said:

I'm planning a similar set up to @Craigm, except I have a solar geyser.

Was also planning on setting up on the non essential side, but then have a problem if no grid.

What would be ideal is if I could have the pump and geyserwise controller on essential, and the element on non essential. This way atleast I will have hot water at night if no power in the day. Not sure if thats possible though?

Would still have an issue in the morning though.

I use a heat pump which is on the essentials load. Why would you want to put it on non essentials? I assume the pump doesn't use much power.

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3 minutes ago, phidz said:

I use a heat pump which is on the essentials load. Why would you want to put it on non essentials? I assume the pump doesn't use much power.

I want the element on non essential and pump and controller on essesntial.

Thinking is to have the element on non essential so that It doesnt drain all the battery and possibly cause a trip if loadshedding hits.

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1 minute ago, Mark M said:

I want the element on non essential and pump and controller on essesntial.

Thinking is to have the element on non essential so that It doesnt drain all the battery and possibly cause a trip if loadshedding hits.

oh i see, you will have to separate them on the db i guess

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After Numerous installs and lots of hair pulling ... yes im nearly bald.
This is what i've found and believe me its not what it says on the box .!!!!
CT coil installed on the grid side . When grid is on and excess solar available Meaning batteries are charged it supplies these devices and appliances by pushing power back to the CT --- AND DRAINS THE BATTERY.
The ideal situation is that batteries are charged and excess solar is available supply the CT Side of the grid and DONT DRAIN BATTERIES.
But sadly it does and uses battery power till its empty to keep these appliances alive if the grid is on and working .. in short whats the point other then selling excess power to the grid .

So moved on and decided to redesign again .
This time did an install using the Two outputs .
Load and GEn input ( known as Aux on the Sunsynk)
I was told by the engineers that it would work like this .

Critical loads on load would always be powered by the unit and when batteries are low using the system work mode table preset SOC% it will then go to the grid / and or charge if grid charge is ticked . THIS WORKS AS INTENDED ON ALL SETTINGS SCENARIO

Aux/gen input enabled with on at 95% off at 90% and power set to 1000w . Ticking always on grid . Smart load enabled highlighted 

Connected pool pump and geyser to this output and find that it does not work as it should .
If the System work mode (deye ) is ticked and the GEN input is enabled for smart load we end up getting a situation where the Smart load comes off solar but also uses battery below the 90% setting !!! Wrong ..

After speaking to the engineers and technicians numerous attempts ive still not gotten a firm answer from them .Seems the feature is part of the advertising but doesnt work .

The only way to get it work is to have a contactor relay connected and disable always on grid so that the unit powers up the smart load output when its ready example conditions are met . Soc is above and solar in excess ..  And the contactor enables pulls the unit off grid onto inverter and runs till it reaches the turn off point and contactor disables ?

In which case why then are we trying to use a feature that doesnt work !
IF any one can help assist and shed some light it would really help .

 

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19 minutes ago, Zimnismoboy34 said:

After Numerous installs and lots of hair pulling ... yes im nearly bald.
This is what i've found and believe me its not what it says on the box .!!!!
CT coil installed on the grid side . When grid is on and excess solar available Meaning batteries are charged it supplies these devices and appliances by pushing power back to the CT --- AND DRAINS THE BATTERY.
The ideal situation is that batteries are charged and excess solar is available supply the CT Side of the grid and DONT DRAIN BATTERIES.
But sadly it does and uses battery power till its empty to keep these appliances alive if the grid is on and working .. in short whats the point other then selling excess power to the grid .

So moved on and decided to redesign again .
This time did an install using the Two outputs .
Load and GEn input ( known as Aux on the Sunsynk)
I was told by the engineers that it would work like this .

Critical loads on load would always be powered by the unit and when batteries are low using the system work mode table preset SOC% it will then go to the grid / and or charge if grid charge is ticked . THIS WORKS AS INTENDED ON ALL SETTINGS SCENARIO

Aux/gen input enabled with on at 95% off at 90% and power set to 1000w . Ticking always on grid . Smart load enabled highlighted 

Connected pool pump and geyser to this output and find that it does not work as it should .
If the System work mode (deye ) is ticked and the GEN input is enabled for smart load we end up getting a situation where the Smart load comes off solar but also uses battery below the 90% setting !!! Wrong ..

After speaking to the engineers and technicians numerous attempts ive still not gotten a firm answer from them .Seems the feature is part of the advertising but doesnt work .

The only way to get it work is to have a contactor relay connected and disable always on grid so that the unit powers up the smart load output when its ready example conditions are met . Soc is above and solar in excess ..  And the contactor enables pulls the unit off grid onto inverter and runs till it reaches the turn off point and contactor disables ?

In which case why then are we trying to use a feature that doesnt work !
IF any one can help assist and shed some light it would really help .

 

What inverter do you have?

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  • 4 weeks later...

In yesterdays Sunsynk video, the aux/smart load seems to be supplied directly from the battery and not directly from solar.

But I assume if there is solar capacity available the batteries would charge at their max rate and if you only had e.g. a 0.75kW pool pump attached to the smart load they would concurrently discharge at that 0.75kW?

The UPS side however can take power directly from solar.

 

So for the sake of argument what would happen if I have the 8kW inverter with:

UPS loads of 4kWh

Smart loads of 2kWh

solar production of 7kWh

Max battery charge/discharge rate is 5kWh

 

If I'm understanding correctly the following would happen:

UPS loads of 4kWh supplied fully by Solar, so now I have 3kWh of solar production left to use,

Batteries will charge at 3kWh and concurrently discharge at 2kWh to supply the smart load. So the smart load will be running and the batteries will effectively still be charging at 1kWh.

Is that correct and can anyone confirm that it works as such in practice?

 

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13 minutes ago, Robbo said:

In yesterdays Sunsynk video, the aux/smart load seems to be supplied directly from the battery and not directly from solar.

But I assume if there is solar capacity available the batteries would charge at their max rate and if you only had e.g. a 0.75kW pool pump attached to the smart load they would concurrently discharge at that 0.75kW?

The UPS side however can take power directly from solar.

 

So for the sake of argument what would happen if I have the 8kW inverter with:

UPS loads of 4kWh

Smart loads of 2kWh

solar production of 7kWh

Max battery charge/discharge rate is 5kWh

 

If I'm understanding correctly the following would happen:

UPS loads of 4kWh supplied fully by Solar, so now I have 3kWh of solar production left to use,

Batteries will charge at 3kWh and concurrently discharge at 2kWh to supply the smart load. So the smart load will be running and the batteries will effectively still be charging at 1kWh.

Is that correct and can anyone confirm that it works as such in practice?

 

I don't think it's possible for the battery to charge and discharge at the same time.

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Got some clarity from Keith, the problem lies in terminology, where it says SOLAR POWER (W), should be LOAD LIMIT, this is where you enter the maximum wattage of the load, eg I have a 1100 watt pool pump, so i should input lets say 1150 watts, now when the battery is within the percentage limits , smart load should switch on and when either the load exceeds the 1150 or battery soc drops to the cut off percentage , then the smart load should switch off,

it has nothing to do with available excess solar power, will try it today to see how it works.

Edited by Tariq
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