I am doing my first install and basically want it setup as per Victron ESS system. it will run on battery / PV expect if it gets to 20% SOC. i have looked at the seetings and manuals but i am a bit puzzled . Can anyone help me ?

You can manage the minimum battery levels with the 'Time Of Use' settings under Grid Setup. I have included pictures of mine as an example. PV will be used first, and it will utilise the battery as long as the current state of charge is higher than the set minimum for that time of the day.  When it hits the minimum it will use grid power. You can also use this screen to set charging from the grid (if you have a couple of cloudy days and solar is not enough to fully charge). Note that these percentages don't limit charging from PV (so even if it is set to 80%, it will attempt to charge the battery to 100% from PV as long as there is sunlight). It does however limit charging from the grid (so if it is set to 80% at 21:00 with grid charge ticked, it will only charge to 80%).

 

My 'Grid Sell' is unticked, so it does not export power to the grid. 'HM Load & Zero Export' is ticked, which means it pushes power back into the non-essential loads that are not on backup (in my case this is the geyser and stove).  It does this via the grid input (it is bi-directional), and you need to have the CT clamp fitted to use this option. It will attempt to zero grid usage by using PV and battery to push into the 'home load'. So if you use this option and you have very low minimum battery levels set, you could run your batteries flat by using your stove for example. I have my geyser timer set to turn on at 12:00, at which time my minimum battery level is 100% - so the inverter will push all excess PV into the geyser without using the battery.

 

If 'LD Load & Zero Export' is ticked, it will only power the backed up loads and not push any power back into the non backed up circuits.

 

I understand that the newest firmware looks slightly different, but it should be quite similar.

Also make sure that 'Time of Use' is ticked, and underneath that all of the days are ticked.

17 hours ago, Bernardf said:

by using your stove for example. I have my geyser timer

So the battery % is the minimum at the time in question?

This is actually the SoC ?

By 9am you battery is at 85% SoC?  How did it get there, no sun, no grid ticked from 60% SoC at 05:00?

Not very intuitive..

What would my settings be if I wanted to take the battery down to a low point of 30% SoC (70% DoD) between 23:00 and 06:00, the rest of the day it must be charged by the sun and if it has not hit 100% at 17:00 use the grid to charge?

 

These are the minimums that the inverter looks at in order for it to decide whether to use battery power or grid power to supplement available PV to power the loads (so during load shedding these minimums are not applicable as there is no grid power). 

In my example, from 09:00 to 12:00 the inverter will not use battery power if the actual SoC is less than 85%.  So if actual SoC is 70% at 09:30, it will power loads with excess PV (whats left over from what the battery is pulling from PV to charge) + grid. If actual SoC is 90% at 11:00, it will use PV + battery, but it will stop discharging the battery when it is down to 85%.  From 12:00 to 17:00 it will use PV + grid. After 17:00 it will start using the battery, but at 85% it will use grid power, etc.

As for your question, please see the picture below. The value you enter at 06:00 will depend on your preferences. If you put 100%, you will just use PV + grid from 06:00 to 17:00, and only use your battery in the 23:00 to 06:00 period.  If you put 30% at 06:00, your battery will still charge from PV up to 100%, but throughout the day it might be discharged and re-charged a little bit multiple times if your loads are higher than available PV. If the minimum is too low in the afternoon you have to consider that you might be caught out by loadshedding, for example if you have big loads in the late afternoon on a cloudy day, you could sit at 30% SoC at 16:55 (thinking that you'll grid charge after 17:00). Then Eskom might move up a stage and you have unplanned load shedding without sunlight and with only 30% battery. That's why my minimums are quite high for the early evening.

Good day

I want to set up. My sunsynk to use pv first then battery then grid for loads and to charge the battery. Will this settings work to accomplish this? 

23 hours ago, Charlesk said:

Good day

I want to set up. My sunsynk to use pv first then battery then grid for loads and to charge the battery. Will this settings work to accomplish this? 

In the latest software there is an option to give priority to load first. 

 

What will happen is that PV power will first go to the loads. When PV generation exceeds the load, it will then start charging the batteries. 

You will need to set time off use settings for when PV generation starts to decrease and it will then use batteries to supplement this until a certain SOC is reached. After this it will then go to the grid and then repeat the process the following day. 

I would also set it to not charge from the grid. 

 

Bernardf

Thank you for taking time to give this info for guys like me. Appreciated.

 HM LOAD & ZERO EXPORT   

LM LOAD & ZERO EXPORT    

what is the difference

Thanks

   

                   

would they normally, both be ticked at the same time ?

so if HM is ticked, will pv ALSO be pushed also to essentials ( LOAD output ) or would it use batteries ????, as on a Victron it pushes pv power to both essential and non essentials, the inverter sees it all as one load

Apologies for all these questions

 

Edited November 12, 20205 yr by Tariq
.

Actually, just bought a 3.6, not hooked up yet, was looking at @Bernardf's post.

again, you guys have been a big help, thanks 

Hi

 

If I have for example either the 3.6 or the 5 kW Sunsynk inverter, it wont have any batteries connected, but will have say 2.8 Kw of pv. Now if the pv is producing say 2 KW and the house load on both the essentials and non essentials side is 2.6 KW will it take the 2 KW from the pv and "add" the 600 w from grid.

Second question, lets say we have a power failure (load shedding), without a battery connected will the inverter turn off completely? If not what would happen in the above scenario, would it just drop the non-essentials side of the load and as long as I have enough pv to run the essentials would it run? What happens if the essentials side exceeds pv production?

If it turns off, what is the minimum size battery I would have to connect to keep it on using pv while grid is off.

how far can the CT be run from the inverter?
I would need the CT to be about 15m from the inverter to get to the cable between my meter and my non-essential load DB. Would this be doable?

9 minutes ago, RhysMcW said:

how far can the CT be run from the inverter?
I would need the CT to be about 15m from the inverter to get to the cable between my meter and my non-essential load DB. Would this be doable?

IIRC it can go up to 20m. Extend with twisted twin core cable, and try to keep it away from AC lines.

3 minutes ago, JustinSchoeman said:

IIRC it can go up to 20m. Extend with twisted twin core cable, and try to keep it away from AC lines.

Thanks @JustinSchoeman, that's good news, will just need to find a route away from the AC cables which will prove a challenge, but doable...

11 hours ago, Greglsh said:

Hi

 

If I have for example either the 3.6 or the 5 kW Sunsynk inverter, it wont have any batteries connected, but will have say 2.8 Kw of pv. Now if the pv is producing say 2 KW and the house load on both the essentials and non essentials side is 2.6 KW will it take the 2 KW from the pv and "add" the 600 w from grid.

Second question, lets say we have a power failure (load shedding), without a battery connected will the inverter turn off completely? If not what would happen in the above scenario, would it just drop the non-essentials side of the load and as long as I have enough pv to run the essentials would it run? What happens if the essentials side exceeds pv production?

If it turns off, what is the minimum size battery I would have to connect to keep it on using pv while grid is off.

Q1: Yes.

Q2: The Sunsynk cannot operate only on PV, so it will shut down.

Q3: Sunsynk support suggests that even a very small battery would be OK.

I would suggest that you watch the training video, it will answer a lot of your questions:

Edit: Thgis is a better video, it gets straight to the point:

 

Edited November 13, 20205 yr by YellowTapemeasure

6 minutes ago, Vassen said:

It’s just the ct cables cannot run in the same conduit as the AC as you end up with interference.

CTs are current sources and therefore the signal is very immune to noise. You shouldn't see any interference if you run the cables in the same conduit as the AC.

38 minutes ago, Vassen said:

For the actual cable, I could not find the twisted cable, so I bought 0.5mm single cable and braided it myself similar to the original. The twisting helps prevent / reduce  interference. 

I wonder if network cable, which is twisted anyway, would work or is the gauge too small? I seem to recall reading on the OpenEnergyMonitor site that they mention using network cable to extend the CTs and temperature probes.
Network cable seems to vary from gauge 22 (0.63mm) down to 28 (0.33mm) so possibly could work, you also get STP (Shielded Twisted Pair) that has a nice aluminium shielding to reduce AC cable interference when you need to run a LAN cable next to an AC cable, but then @Stanley mentions the interference should not be an issue anyway so probably not necessary...

1 hour ago, Vassen said:

My understanding based on what I have read is that the ct coils are based on Hall effect.

CTs and Hall-effect sensors are 2 completely different things, although both are used for measuring current. CTs are passive devices (they really are just transformers) where the current in the secondary (the only winding on the CT) is proportional to the current in the primary (the conductor through the middle). This makes the CT a current source. In order to measure the current, the measuring device will usually have a burden resistor at the measuring end so that the voltage across the burden resistor is proportional to the current and will not be affected in any way by cable length etc. as any other voltage drops or resistance in the circuit will have no effect on the measurement. The burden resistor is usually quite a low resistance (often a fraction of an ohm) meaning it is very difficult for noise to cause a measurable voltage across the burden resistor. Of course the design of the measuring circuit is also important to make sure it get's rid of / can handle common mode noise. Putting the burden resistor at the CT instead of in the inverter / measuring device would of course negate the benefit of the CT being a current source.

Hall-effect sensors are active devices (they have electronics in them that need to be powered) that measure current using the hall-effect, which means that they can measure both AC and DC current (unlike CTs which can only measure AC). Since they are active devices, their output depends on the circuit design. You can get these with a whole range of output options including current outputs (although this is most likely done using an opamp in a current source configuration).

So I guess it depends on what the Sunsynk uses to measure the current. Is it a CT or a hall-effect sensor?

3 hours ago, RhysMcW said:

I wonder if network cable, which is twisted anyway, would work or is the gauge too small? I seem to recall reading on the OpenEnergyMonitor site that they mention using network cable to extend the CTs and temperature probes.
Network cable seems to vary from gauge 22 (0.63mm) down to 28 (0.33mm) so possibly could work, you also get STP (Shielded Twisted Pair) that has a nice aluminium shielding to reduce AC cable interference when you need to run a LAN cable next to an AC cable, but then @Stanley mentions the interference should not be an issue anyway so probably not necessary...

Popular network cables which ought to work:

Cat 5E : 24AWG

Cat 6 : 23AWG

Cat 6A : 22AWG

Personally, I would use 22AWG, but wouldn't use a shield due to capacitance issues (requiring grounding on both ends. It's just too much trouble.) UTP should be fine.

If they are using CTs, then if you know the CT ratio you can easily calculate the current in the secondary for a particular primary current.

adding this for anyone that may have been following this thread for the CT extending discussion...

I've just recently purchased a Sunsynk 5kW 1P and installed it but needed to extend the CT cable.
My CT is about 17 meters from the inverter. I extended the cables using the same type of wire (0.5mm panel or flex wire) as the CT comes with, which I found at ACDC, and twisted them. I had to purchase 100m length of each colour as they don't sell that by the meter, but it's not that expensive thankfully.
My CT appears to be working fine.
The only "issue" I came across is the the CT readings on the Sunsynk did not show anything until I switched on the grid power to the inverter, which had me going for some time thinking the cable extension was not working.

Hello all. Late to the party on this conversation but having a Sunsynk 5KW and some lithium batteries means that we often discover things as we go along.

@bernardf posted his time of use settings. 

My unit is basically set to 100% from 8am to 6pm. So the batteries only charge during the day when there is sufficient sun. Then discharge in stages from 6pm to the following 8am all the way down to 30% SOC. I have ticked the load priority checkbox so when load is high during the day, it stops charging the batteries for a period of time to attend to the load and blend with grid if necessary. So on a good sunny day my 7kw of batteries are usually charged by 1pm. Thereafter the PV attends to the load for the rest of the day.

Not really concerned whether @Bernardf's settings are good or bad, i am more interested about the way the batteries work. So in his setup, theoretically, the battery could be charged and partially discharged multiple times in the day. If the load at any point in the day demands more than what PV can supply and if the the battery has the required SOC for that time of day, the system could engage the use of the battery to power the load in tandem with PV and maybe even grid. When load demand drops, PV may get back to charging the battery.

MY QUESTION IS: When the battery charges up to maybe 80% then allowed to discharge to perhaps 65% and then charge up again, is this not using up a charging cycle of the battery???

If this is true, then does it mean that multiple charge cycles are used up each day, and therefore reducing the lifespan of the battery???

With lithium batteries quoting in excess of 6000 cycles (based on DOD), the above scenario, if true, could mean that the batteries state of health (SOH) could deteriorate well before the claimed 10 years that most lithium vendors make. 

Any comments on the above???!!! Not sure if this has been discussed in another thread before.