Just a thought. Can I use a timer to switch my solar panels on and off? Got the system up and running again, followed the great advice from the forum members.

The reason for my thinking is; I have the crappy clone fake inverter and in the early morning  and late afternoon (between 06h00-07h00 and 16h00-17h00) the bloody thing does not know what to do.

It switches between solar and battery a dozen times when the pv input is trying to generate power (between maybe 40w to 60w) Not exactly sure, but around there.

Would it be better if I keep the panels off between 16h00 and 07h00 and have them switch on once the sun is up? I will bear with it if its cloudy or overcast or whatever.

So far pv has saved me about 250 units ( about R471.00). That's R471.00 eskom is NOT getting from me🙂.

Great forum as always. Thanks to Coulomb, SilverNodashi, The TerribleTriplet. (en die oom met die groot baard) Much appreciated.

It is possible but switching DC on or Off is quite expensive compared to AC as you get a problem with the ARC on DC. Would there be an option to switch the inverter on or off on the AC side? Then the inverter would not have any load on it and should be running ok'ish?

24 minutes ago, PaulF007 said:

It is possible but switching DC on or Off is quite expensive compared to AC

Indeed.

It may be possible to connect a tiny computer (say an Arduino) to the comms port of the inverter (I'm assuming it's an Axpert clone), and send some commands to change mode at the appropriate time of day. For example, set Output Priority to Utility for that hour or so, then back to whatever you usually run.

But if you're referring to the small internal relay that turns off the output of the solar charge controller around dusk, the above won't fix that. You could change Charge Source Priority to Utility first for that hour, perhaps also setting the maximum utility charging to 2 A for the duration.

Thanks PaulF007

Was just thinking about my plan and I read somewhere that everything must be switched on and off in a certain sequence. I could just maybe blow something up.

Instead of the DC side, switch the AC side between inverter and Eskom. I did that for years.

Geeez people... if you need to switch DC and it's not for safety function reasons, it doesn't have to be a mechanical switch. Use a large FET to do the switching 🙂

Of course this advice is not going to help if you're not at least half-electronics-literate. But there are quite a few examples for this that you can google.

Of course the proper way to do this is an N-channel FET in the positive line with a 15V source above that to drive the gate nice and hard, but it might be easier to hack it into the negative side.

8 hours ago, Warlok said:

Just a thought. Can I use a timer to switch my solar panels on and off? Got the system up and running again, followed the great advice from the forum members.

The reason for my thinking is; I have the crappy clone fake inverter and in the early morning  and late afternoon (between 06h00-07h00 and 16h00-17h00) the bloody thing does not know what to do.

It switches between solar and battery a dozen times when the pv input is trying to generate power (between maybe 40w to 60w) Not exactly sure, but around there.

Would it be better if I keep the panels off between 16h00 and 07h00 and have them switch on once the sun is up? I will bear with it if its cloudy or overcast or whatever.

So far pv has saved me about 250 units ( about R471.00). That's R471.00 eskom is NOT getting from me🙂.

Great forum as always. Thanks to Coulomb, SilverNodashi, The TerribleTriplet. (en die oom met die groot baard) Much appreciated.

What inverter do you have? Some of the inverters can be programmed to switch from solar to batteries or grid as a specified time. 

 

Switching DC requires big and expensive SSR's or MOSFET's and can be dangerous if not done properly. Someone, somewhere else, recently had some bad experience with some SSR's that burned out with much lower ampere than stated. And they were brought from a reputable store. 

9 hours ago, plonkster said:

Geeez people... if you need to switch DC and it's not for safety function reasons, it doesn't have to be a mechanical switch. Use a large FET to do the switching 🙂

Of course this advice is not going to help if you're not at least half-electronics-literate. But there are quite a few examples for this that you can google.

Of course the proper way to do this is an N-channel FET in the positive line with a 15V source above that to drive the gate nice and hard, but it might be easier to hack it into the negative side.

Thanks Plonkster. Built my first little 8bit pc in st6 to do home automation. Control lights and so on. Used 8 relays to control the shebang. Actually was a school project. Got an F for that because it wasn't the norm, (everybody else had what a normal st6 child had). Good times (1981) Also thought what it would like to be able to have a device I could hold in my hand to do everything, like the smartphones of today. But, wrong time, wrong place. Thanks for the advice. Will give it a go.

23 minutes ago, Warlok said:

The barcode number is the same . So the 2 clones is from the same factory . So the odds is very high that the SCC is also going to disconnect by cloud movement . 

8 hours ago, SilverNodashi said:

What inverter do you have? Some of the inverters can be programmed to switch from solar to batteries or grid as a specified time. 

 

Switching DC requires big and expensive SSR's or MOSFET's and can be dangerous if not done properly. Someone, somewhere else, recently had some bad experience with some SSR's that burned out with much lower ampere than stated. And they were brought from a reputable store. 

Can I maybe use a contactor wired to a simple electronic timer? I'm going to blow something up, just wait and see.....

Edited May 6, 20197 yr by Warlok
Forgot something

4 minutes ago, Warlok said:

Can I maybe use a contactor wired to a simple electronic timer? I'm going to blow something up, just wait and see.....

Put this in between the panels and the pv input? Simple, 08h00 on and 16h00 off?

Lack of responses are that we've been down this track before, most of us "old" members.

There is what I did.
What Plonskter said.
What Siilver said.
Then there is ICC.
Then there is getting a better inverter - before spending a lot of time, money and effort on the unit.

Another point to ponder: Now you find 8-4pm are the benchmarks, but what if there are not ideal weather, then the unit gets confused the whole day.

Whatever you do, focus on the SOC - if it is lead acid. 
For that you need a BMV. Use the BMV's relay to switch the inverter between AC and panels. Then the weather has no impact.

Thanks Tripple T. I'm sure my second inverter will be a much better choice after all of you guys help. I'll just ride this one like a rental till it explodes.

20 minutes ago, Warlok said:

I'll just ride this one like a rental till it explodes.

Man I laughed! 🤣

2 hours ago, Warlok said:

Built my first little 8bit pc in st6 to do home automation. Control lights and so on. Used 8 relays to control the shebang. Actually was a school project. Got an F for that because it wasn't the norm

I did something similar, but only in std. 9. Used a good old PC. Turbo Pascal back in the day. Parallel port with a bunch of relays. Everyone thought it was very cool... 🙂

 

4 hours ago, Warlok said:

Can I maybe use a contactor wired to a simple electronic timer?

If the contactor is rated for DC. The one you posted a picture of didn't appear to be DC rated.

It might be a lot easier to install a cheap external MPPT instead, and leave the buggy internal solar charge controller alone.

10 hours ago, Warlok said:

Ok so that's an Axpert, or a clone. You can use ICC to schedule the time to grid and time to solar. Or you can write your own Python code for this. There are some free scripts on  Github that can read the Axpert data, using a Raspberry Pi. 

On 2019/05/07 at 2:22 AM, Coulomb said:

If the contactor is rated for DC. The one you posted a picture of didn't appear to be DC rated.

It might be a lot easier to install a cheap external MPPT instead, and leave the buggy internal solar charge controller alone.

Thanks man. 

Point #2 on the sticker have me worried a bit. "DO NOT disconnect pv panels or batteries while load is connected"

Sometime I should just RTFM

On 2019/05/06 at 12:37 PM, Guest said:

Instead of the DC side, switch the AC side between inverter and Eskom. I did that for years.

Instead of the DC side, switch the AC side between inverter and Eskom. I did that for years. (How can i try this ????)

4 hours ago, Shahxad said:

Instead of the DC side, switch the AC side between inverter and Eskom. I did that for years. (How can i try this ????)

Hi Shahxad you could add a contactor on the Eskom supply power to your inverter and control the contactor with a timer or sonoff switch. What is your reason for switching it off?