Solax X1 SK-SU3700E inverter CT clamp

[kommando]

When faced with lack of support you need to start being a bit creative. So assuming a Gen 2 inverter of one model should be similar to another Gen 2 model from the same maker you can sometimes get info from other manuals.

https://www.solaxpower.com/uploads/file/x1-smart-g2-series-user-manual-en.pdf

Note in the settings you tell the Inverter what is connected as the Meter with the options (page 73)

Mode Select
For Mode Select, the user can choose from Disable, Meter, CT. The default setting is
Disable. When Disable is chosen, the function will be shut off.
When the user wants to enable this function, choose Meter or CT according to the actual
application, the meter or CT is used to monitor energy exported to the grid.

Also look at page 74 for checks on function.

First check that these options are in the settings menu.

 

[SeaGal]

First check that these options are in the settings menu.

I agree; good find! It seems counter-intuitive to me (as I mentioned before) that the Solax doesn't have a configuration for meter/CT type.

Though, when I queried that twice, the OP said...

firstly Solax early version inverters which mine is doesnt have any settings for CT or meter it simply has a RJ45 socket, whereby pins 1 and 8 are CT and pins 4 and 5 are meter modbus. But not both. The later version do indeed have settings to change

and..

Whether or not its enabled in firmware is a diff matter though, but theres def no CT/ Meter settings in inverter.

But yes, I'd say it's worth double and triple checking - if no joy then suggest to sniff the RS485 port. If the Solax isn't sending requests then it's not configured correctly (or not supported at all on that firmware).

 

[Gray17]

Thanks for replies Guys, checked out the inverter manual, it seems a lot newer model then mine.
Went through all settings with Solex Tech on my inverter as he thought the same should be a setting for CT/meter but def Not.
End result Solax say only their own Solex stamped SDM230 meter will work, Eastron say no it should work as same meter just got Solax logo but internally same? So its either a setting incorrect although both say baudcrate etc correct so should but doesnt.
Now they think it may be firmware related ie my firmware too old, Meter firmware too new? Solax wont update it as i didnt buy meter from them, and out of warranty, Eastron say shouldnt be needed Argh back going round in circles.
Anyway giving up with meter, its not meant to be! Going back to CT my friend has a later version Solax inverter that uses a 33.3ma CT but its not used as he has Chint meter on his, says i can borrow it to test on mine, if it works, reasonably accurate and doesnt lock out, then thats the way to go

Thanks

 

[SeaGal]

keep us updated

 

[Gray17]

Good evening Guys,
Well good news of a sort, fitted the loaned CT clamp, a genuine Solax 33.33ma unit supplied new with a series 4 inverter. The CT has a very short lead terminating in a RJ45 plug using same connection pins 1 and 8. You also get a RJ45 to RJ45 extender box too.
So downpowered inverter, disconnected old CT at the Cat5 joint and removed from the external meter cupboard made up a RJ45 to cat 5 extension fitted new CT arrow facing Grid and connected everything up ensuring correct connections.
Powered up inverter, after its test sequence it started generating.
First thing i noticed its a lot more accurate within 5w of home smart display, which is good, next i added my EV charger which put 1.5kw onto the load (this is varied by the Project EVs own CT) immediately the inverter yield increased to meet the new demand, next turned load off, within seconds the inverter went into export, but gradually decreased this to 5w again, so at this time it was running the home load and charging the batts too, but still importing 5w from Grid.
So i then changed export value to 10w thinking this would take up the 5w load and give me 5w export. Unfortunately this didnt happen, it went into 10w export, but then back to 10w import?
So increased inverter export value to 100w same result. What i iwas trying to achieve is home load, batt charging load and very small export to grid, but seems thats not possible, least with this inverter.
That said seems to be working a whole lot better.
Will monitor tonight see if it locks out after idle mode, in morning if not then happy days!

Update - The inverter didnt go into its normal idle mode last night, the display instead showed waiting? However Grid, Battery and PV all showed 0 under settings, so thats one difference, however woke up this morning and Everything back to normal, no faults showing, no lock out and PV generating supplying home load and charging battery as normal.
Maybe thats how it should work? Will evaluate over next few days and keep you posted.

 

[Gray17]

Morning Guys,
Needing some help please.
Well first off new 33.3ma CT clamp is 100% better then the old one, it reads within 40w of the smart meter display.
Whilst this is accurate enough from a data point of view, it prevents the inverter from sticking to the 0w export ive set. What i wanted was to have a 0w export or just a few W export so my solar is covering my home and battery needs, however if set to 0w it sticks at 40w import, if i change inverter settings to 50w export to cover the discrepency it then exports 100s of W? Sure it shouldnt do that. Suppose paying for 40w better then the 240w i use.
Anyway this is why i tried to fit the directly connected Eastron SDM230 meter, but for some reason could not get it talking to inverter using the RS485? This is recomended for my Solax Sk- Su3700E inverter but refused to communicate. So gave up as Eastron was saying it should work, Solax saying only our version will work?
Anyway i read a sticky from a guy who did this mod (SDM230) but with a Growatt inverter, interestingly like mine had no settings on inverter to change from CT to meter, but stated you have to go to your online account and on there is a setting to change.
Now unfortunately my inverter was used so the online account wont work, so i use the local mode, again no setting to change on the app.
Question does anyone have the Solax X1 version 2 SK-Su3700e or 3000e or 5000e etc model that has the cloud based online account and could check if that setting exists online?
Least that way i know what needs to be done to modify to meter use.
Also having an issue now whereby every morning the inverter thows a fault code EPS overload, now it does have EPS but its unused just has a socket with nothing connected to it.
Questions:
First off EPS is only used if the grid fails, it hasnt so shouldnt even come into operation so why the fault code?
Next theres no load on it so how can it see an overload to generate the code?
I have tried altering the battery charge and discharge settings but this hasnt made any difference.
I can reset the code but it comes back next day, should i just ignore it or be worried? Inverter seems to work ok even with code stored in memory.
According to the fault list EPS overload is when your trying to draw more power then the inverter can cope with, fair enough but mine has nothing connected to it, and hasnt lost grid power to even start using EPS mode?
Have to say wishing I'd bought new now!
Many Thanks