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Advice Needed on Axpert Hybrid Solar Inverter setup.


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Hi all. 

I needed some assistance and was wondering if anyone will be able to assist. 

Please excuse my ignorance as I have no background electrical knowledge whatsoever. 

I recently had a solar inverter system setup at my business 3 weeks ago. I was informed that I could only use the system as a back up power supply during power outages as the power generated by the solar panels was not sufficient to power my business during the day and charge the lithium ion batteries... which were draining over the evening. To my knowledge it was set up for off grid use (SBU setting 1). Later it was switched to bypass mode as the batteries were almost dead every morning when coming in, so grid power is supplying all power. 

My current setup includes

1 x 5kva Axpert Hybrid inverter 

2 x leoch 4.8kw lithium ion batteries (9.6kw )

9 x 270w Solar panels - 3’s connected in parallel to prevent voltage drop. 

After reading on the forum, I see that you can setup this inverter using the SOL setting for option 1. I see others also recommend changing setting 16 so that source of charging isn’t solar only.

I just wanted to find out what settings I should select for all the various settings. My requirements are as follows : I have about 12 LED lights, 3 A++ rated fridges, alarm system, camera system and 2 desktops connected to the inverter. The rest is powered directly from the grid (plug points, geysers, Aircon etc). Current usage is around 1.8kw/h with maximum usage not exceeding 2.0kw/h. I would like the system setup so that I am using solar power during the day with the battery providing any additional load that the panels cannot meet. In the evening when there is no solar power I would want the grid to power the business and also top up/ charge the batteries so that the batteries are full should there be a power failure at night.

I hope I have explained the above clearly. Will appreciate any feedback on this matter. 

Many thanks. 

 

 

 

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3 hours ago, Vix said:

After reading on the forum, I see that you can setup this inverter using the SOL setting for option 1. I see others also recommend changing setting 16 so that source of charging isn’t solar only.

Yes, I think you've got it. The SOL Output Source Priority (setting 1) will run off battery (using solar where available) during the day, and switch the loads to grid at night (if present, obviously). You want a combination of solar and grid charging, so you can charge during the day from grid on rainy days, in case you get a blackout on such a rainy day. So the SNU (Solar aNd Utility) charge source priority (16) is what you want.

You want to run off the battery during the day when you can, since that's the only way to use your solar panels effectively.

But you will want to go to utility charging (and therefore utility supplying loads) pretty quickly, since your loads are about equal to your best solar power most of the time, so you can easily fall behind with a few clouds. So as soon as the battery voltage falls to about 3.33 VPC [ edit: that's 85-90% SOC ] (50.0 V, assuming I'm right that your Leochs are 15S), you want to get back to utility charging. So I'd set your Back to Utility voltage (setting 12) to 50, and back to Battery voltage (setting 13) to 52, maybe 53 V. You may need to play with these settings a bit to prevent too many switchings between battery and utility. I have no trouble with these, I never have a computer drop off for example, but you might get annoyed by lights flickering.

Edited by Coulomb
As noted, and added last few words re lights flickering.
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2 minutes ago, Vix said:

Also, can running the system this way cause any damage to the lithium ion batteries? Or perhaps reduce their life span?

Well, this way you'll be using your batteries (which does reduce life, compared to not using them at all :)), but keeping them fairly full. Just keep away from 54 V (3.6 VPC) for too long, as this will reduce life. That's why I suggest 52 V for setting 13, and only 53 V if you need to prevent too many switchings between battery and grid. The battery voltage isn't compensated for load or charging, so 52 V at the inverter may be less than 52.0 V at the battery (depending on your wiring, mainly). Hence 53 V for setting 13, which will be somewhat less than 53 V at the battery itself, might be OK.

So no, no damage, just using them per your stated need (highest priority is to be ready for a blackout).

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Thank you Coulomb! Really appreciate the feedback! Will try those settings and let you know how it goes.

As for all the other settings can I leave them the same? (I’m assuming they are on the default settings).

The attached pic is the Leoch batteries which I have:

 

B5580CBE-9B9D-4328-913A-570B2D1F5981.jpeg

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4 minutes ago, Vix said:

As for all the other settings can I leave them the same?

Some of the defaults are pretty annoying. I'd turn off the beeping (setting 18 bOf), turn off auto return to main screen (setting 19 kEP), turn on overload bypass (setting 23 byE), and you should check that the float and absorb voltage settings (27 and 26) agree with the manufacturer's recommended values.

Check out Chris Hobson's Axpert Settings 1.1: https://powerforum.co.za/files/file/4-axpert-settings/ .

 

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1 hour ago, Vix said:

Any idea what could be the problem?

Was it a Residual Current circuit Breaker with Overload protection (RCBO)? (Like a two position breaker, but with a "test" button). If so, it might be wired before the inverter, and needs to be wired after it. But I would have thought that you would have had that problem before now.

Or is it an ordinary circuit breaker that connects to your inverter's AC input?

Otherwise, I have no idea why it would be breaking now when not before.

Perhaps put the settings back to what they were, to convince yourself that it really is related to the inverter (it might be a coincidence).

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4 hours ago, Coulomb said:

Was it a Residual Current circuit Breaker with Overload protection (RCBO)? (Like a two position breaker, but with a "test" button). If so, it might be wired before the inverter, and needs to be wired after it. But I would have thought that you would have had that problem before now.

Or is it an ordinary circuit breaker that connects to your inverter's AC input?

Otherwise, I have no idea why it would be breaking now when not before.

Perhaps put the settings back to what they were, to convince yourself that it really is related to the inverter (it might be a coincidence).

I have no idea. Unfortunately not sure what circuit breaker is used. 

Definitely wasn’t tripping (as it was fine for the last 3 weeks) when I had the initial setting 1 on Utility, setting 12 was on 48V and setting 13 on 54V. Also had setting 16 non CSO.

I have attached some pics to show you the setup. 

This morning after the mains were tripped about 4 times, I increased setting 12 to 53V (from 52V) as I noticed it was switching a lot. Will monitor from here on. 

2ADA9F02-32A9-45BD-A27A-8C0C46881D50.jpeg

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On 2019/02/01 at 2:30 PM, Coulomb said:

Some of the defaults are pretty annoying. I'd turn off the beeping (setting 18 bOf), turn off auto return to main screen (setting 19 kEP), turn on overload bypass (setting 23 byE), and you should check that the float and absorb voltage settings (27 and 26) agree with the manufacturer's recommended values.

Check out Chris Hobson's Axpert Settings 1.1: https://powerforum.co.za/files/file/4-axpert-settings/ .

 

Do you perhaps know what the float and absorb voltage settings should be for the battery I have as above? 

Could this be causing the tripping? 

Also it has been quite overcast today... minimal sunshine. Could this be a factor contributing to the problem? 

 

Many thanks. Sorry for all the questions. Just not sure what to do. 

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9 hours ago, Vix said:

I have no idea. Unfortunately not sure what circuit breaker is used. 

Can you take a photo of inside the Distribution Board, and indicate which breaker is tripping?

9 hours ago, Vix said:

Definitely wasn’t tripping (as it was fine for the last 3 weeks) when I had the initial setting 1 on Utility, setting 12 was on 48V and setting 13 on 54V. Also had setting 16 non CSO.

So your Output Source Priority (setting 1) was Uti, that means the unit would be in bypass mode all the time, not running the inverter. So it looks like something causes the tripping when the inverter is running. It's still possible that you have a Residual Current Device (with or without Overload protection) before the inverter, and that this only trips when the inverter is running.

Quote

I have attached some pics to show you the setup. 

Is it one of the breakers near the inverter that is tripping, or one in the main Distribution Board further away?

Quote

This morning after the mains were tripped about 4 times, I increased setting 12 to 53V (from 52V) as I noticed it was switching a lot. 

To stop excessive switching, you want a larger difference between settings 12 and 13 (when utility charging comes on, and when it comes off, respectively). With setting 12 too high, you'll be charging your battery a lot, which will waste utility power, and will reduce the life of the battery a little. So I'd increase setting 13 instead, or even reduce setting 12.

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On 2019/02/02 at 10:39 PM, Vix said:

Do you perhaps know what the float and absorb voltage settings should be for the battery I have as above? 

The brochure I downloaded didn't have a recommendation. So I suggest using the same absorb and float settings as the Pylontechs. Sorry, you'll have to search for that yourself. [ Edit: actually, the settings are different, see Virge's post below. ]

Two other settings come up, however. The minimum battery voltage should be 40.5 V, but I'd leave it at the default of 42 V, or even increase it anywhere up to the maximum of 48 V (for maximum battery safety, at the cost of slightly less run-time in the case of a long blackout). [ Edit: limit this to 46 V unless using LFP patched firmware; see this post below. ]

The other thing is that when paralleled, the maximum charge current should be 20 A per unit. So setting 02 (maximum total charge current) should be 40 A.

Quote

Could this be causing the tripping? 

I don't think so.

Quote

Also it has been quite overcast today... minimal sunshine. Could this be a factor contributing to the problem? 

I doubt it. Oh wait; the inverter part of the inverter-charger will be running when utility charging (the inverter is "run in reverse" for battery charging from utility). If my guess about the RCD before the inverter is correct, then less sunshine would mean more utility charging which would mean the inverter proper is running more of the time, increasing the chances of a nuisance trip.

The other slight possibility is problems due to a non-genuine (clone) inverter-charger; some of the clones look very similar from a distance (e.g. I can't tell from your photo). You could run through the genuineness section of this post (just the dot point above the first photo), or post a photo of the sticker(s) on the side of your machine. Include the nearest lid-to-case screw in the photo if possible. Cloned machines may have less suppression of electromagnetic interference, or other limitations.

Edited by Coulomb
"mains charging" -> "utility charging" for consistency
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Many Thanks for your most valuable input Coulomb.

As per your questions:

1. I will take a photo of the distribution board with the cover off post it up tomorrow. The main switch is tripping on the main DB board itself which is quite a distance (maybe 5 meters) away from the inverter. See attached pic below. The mains (on the extreme left) is tripping. 

 

2. Will try play around with the settings on setting 12 and 13 and also review the maximum charge current and minimum battery voltage settings. To my knowledge the minimum battery voltage is set at 42v and the maximum charge current is at 60A. Should I change it to 40A? 

3. Will take close up pics of the inverter and also post them up tomorrow. I hope it’s not a clone machine.

Kind regards,

Vikash 

 

 

C9D825EF-A430-430F-8582-F63A59201090.jpeg

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4 hours ago, Vix said:

1. I will take a photo of the distribution board with the cover off post it up tomorrow. 
 

But that photo you posted is the main DB already, correct?

Quote

 

The main switch is tripping on the main DB board itself which is quite a distance (maybe 5 meters) away from the inverter. See attached pic below. The mains (on the extreme left) is tripping. 

 

Well, there's your problem. Firstly, your main breaker is an RCBO (Residual Current circuit Breaker with Overload), which is a Residual Current Device combined with a circuit breaker. 50 A seems a little low to me, but I guess this is a business with no stove/oven or other high powered devices.

The other thing is that it's a 20 mA device; usually you see 30 mA in Australian homes, and 50 mA or higher in industry where there are many inverters for motor drives.

So this is a sensitive RCD before the inverter. This will often cause tripping. I'm surprised it hasn't been tripping before now, on the old settings.

I don't know anything about South African regulations, so I don't know what will be possible. But I would hope that you could replace the RCBO main breaker with a 50 A ordinary circuit breaker and a 50 A RCBO after it. In fact, you could use the same RCBO, just put a 50 A ordinary breaker in front of it. Then the inverter breaker (the 30 A one, it should be adequate if you don't do a lot of utility charging while also running high loads) should connect after the main breaker but before the RCBO. It looks like your electrician will have enough room to shuffle the other breakers to the right to achieve this.

But then for safety, you need an RCBO at the output of the inverter. This could perhaps go into one of the small breaker boxes near the inverter; hopefully, there is one already there.

Quote

and the maximum charge current is at 60A. Should I change it to 40A? 

Yes.

Quote

3. Will take close up pics of the inverter and also post them up tomorrow. I hope it’s not a clone machine.

Yes. I was just looking at a Synerji work-alike (not quite a complete clone), and was not impressed with what I saw.

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5 hours ago, Coulomb said:

But I would hope that you could replace the RCBO main breaker with a 50 A ordinary circuit breaker and a 50 A RCBO after it

Yup, it's pretty common to split this up. You'd have a 50A (or 35A, or 60A, or however much your connection is rated for) double-pole breaker as a main switch (so it serves as both an issolator and overcurrent protection), followed by a 30mA RCD (no overcurrent protection since you already have the other one), followed by the rest of the individual breakers.

That board on that photo is extremely old. You can't even get those big old breakers anymore. It would likely turn into a "rip out and redo" thing.

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17 hours ago, Coulomb said:

But that photo you posted is the main DB already, correct?

Well, there's your problem. Firstly, your main breaker is an RCBO (Residual Current circuit Breaker with Overload), which is a Residual Current Device combined with a circuit breaker. 50 A seems a little low to me, but I guess this is a business with no stove/oven or other high powered devices.

The other thing is that it's a 20 mA device; usually you see 30 mA in Australian homes, and 50 mA or higher in industry where there are many inverters for motor drives.

So this is a sensitive RCD before the inverter. This will often cause tripping. I'm surprised it hasn't been tripping before now, on the old settings.

I don't know anything about South African regulations, so I don't know what will be possible. But I would hope that you could replace the RCBO main breaker with a 50 A ordinary circuit breaker and a 50 A RCBO after it. In fact, you could use the same RCBO, just put a 50 A ordinary breaker in front of it. Then the inverter breaker (the 30 A one, it should be adequate if you don't do a lot of utility charging while also running high loads) should connect after the main breaker but before the RCBO. It looks like your electrician will have enough room to shuffle the other breakers to the right to achieve this.

But then for safety, you need an RCBO at the output of the inverter. This could perhaps go into one of the small breaker boxes near the inverter; hopefully, there is one already there.

Yes.

Yes. I was just looking at a Synerji work-alike (not quite a complete clone), and was not impressed with what I saw.

Thanks Coulomb. 

Yes, the pic I posted was of the main distribution box. 

So I guess I need to have the circuit breakers adjusted as you have advised. Have called the electrician and he said he will come in the week. 

Is this picture below an RCBO for the inverter? It is found in the box just below the inverter. 

The mains must have tripped last night and the batteries ran till they were dead this morning. I have changed the settings this morning back to original settings and have not had a trip since (touch wood). It doesn’t seem to be tripping when it is set in Utility mode, with utility supplying the load and the panels just charging the batteries. 

29E9CCC3-9D5E-4104-B480-B5C319369CDF.jpeg

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4 hours ago, Vix said:

Is this picture below an RCBO for the inverter? It is found in the box just below the inverter. 

No, on the output you appear to have just a double-pole isolator and a surge protector.

4 hours ago, Vix said:

The mains must have tripped last night and the batteries ran till they were dead this morning.

If you want to prevent that, make the battery low voltage cutoff higher, say 46 V.  (This is setting 29). This will cost you a few minutes in long-blackout runtime. Being a lithium battery, running low doesn't matter as much as with lead acid, but it's probably worth doing, perhaps when everything is sorted out. I say 46 V rather than 48 V because otherwise it will affect settings 12 and 13. If you decide to use the patched firmware (you would use the LFP version), then this consideration effectively goes away. I forgot to mention this consideration in an earlier post; corrected now.

4 hours ago, Vix said:

I have taken pics of the inverter box itself but unfortunately I cannot upload it. It doesn’t allow me to upload more than 1 pic (or 3mb) per day :(

Today's picture was just 56 kB, so I don't think you're hitting the 3 MB limit. I expect that after you've had a certain number of posts, that limit will be more generous. You're at 11 posts now; maybe you can already post it (thanks to the post where you tell us you can't post it putting you over the threshold 🙂 ).

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  • 2 weeks later...
On 2019/02/03 at 12:18 AM, Coulomb said:

The brochure I downloaded didn't have a recommendation. So I suggest using the same absorb and float settings as the Pylontechs. Sorry, you'll have to search for that yourself.

Two other settings come up, however. The minimum battery voltage should be 40.5 V, but I'd leave it at the default of 42 V, or even increase it anywhere up to the maximum of 48 V (for maximum battery safety, at the cost of slightly less run-time in the case of a long blackout). [ Edit: limit this to 46 V unless using LFP patched firmware; see this post

Different from Pylontech

IMG-20190218-WA0000.jpg

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  • 1 month later...
On 2019/02/01 at 2:20 PM, Coulomb said:

Well, this way you'll be using your batteries (which does reduce life, compared to not using them at all :)), but keeping them fairly full. Just keep away from 54 V (3.6 VPC) for too long, as this will reduce life. That's why I suggest 52 V for setting 13, and only 53 V if you need to prevent too many switchings between battery and grid. The battery voltage isn't compensated for load or charging, so 52 V at the inverter may be less than 52.0 V at the battery (depending on your wiring, mainly). Hence 53 V for setting 13, which will be somewhat less than 53 V at the battery itself, might be OK.

So no, no damage, just using them per your stated need (highest priority is to be ready for a blackout).

Hi Coulomb, sorry for jumping in at this point, but is the Axpert King Inverter not a better "Hybrid Inverter" to have the ability to combine Solar an Utility (Eskom) rather than supplying Utility via the battery?

What are your thoughts on the Axpert King Inverter?

Jaco

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On 2019/04/01 at 12:34 AM, Jaco Venter said:

is the Axpert King Inverter not a better "Hybrid Inverter" to have the ability to combine Solar and Utility (Eskom) rather than supplying Utility via the battery?

I've not thought about the King very much, other than to note it as a possible future purchase. Your question prompted me to look at it a bit more closely.

I see that it still has a bypass mode, so if the load exceeds what the inverter can handle, it can still use a relay to supply the loads from AC-in. (I've corrected an earlier post where I thought it could not do that.)

Line mode seems to supply the loads from AC-in via the battery. In fact, the only difference between line and battery mode seems to be that the AC charger is active, and it can be active while the inverter is supplying the load partly from the battery and/or solar. So yes, that's an advantage: when the battery gets low, the AC charger can kick in, without the inverter having to turn off and turn into a charger.

Quote

What are your thoughts on the Axpert King Inverter?

It seems a good design. at least at first glance. It seems to be about the same price as the Axpert MKS.

But of course, there is no patched firmware at present. They have at least made a start: according to the manual the "r" is now rendered properly 🙂  But I fear that the premature float bugs will still be there.

[ Edit: I meant to add that Voltronic Power don't call the King a "hybrid" inverter; it's classed along with all the other Axpert models as "off-grid". It still doesn't have the ability to push power into the grid; if it did, it would need a world of approvals that would push the price up. Though I note that some of the clones manage this.

I note that line mode on the King comes close to achieving much the same thing: as long as the load doesn't exceed what the inverter can supply, you can blend solar, battery, and AC-in power to supply the load. ]

Edited by Coulomb
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