Hi,

Hope you are all well. I'm very new inverters and frankly, still really don't understand much. I've been reading up online to get an understanding over how my system functions but I am still missing some pieces and I believe that my installation is not operating optimally.

I have the Mecer 5kva inverter, with 9x300w solar panels and a single 4.8kw lithium ion battery.

The system is configured to use SOL as operating mode, with the rest of the options on default. During the early morning's, I see that the battery is full and that the unit is using power from solar indicated by the LCD screen but sometimes, around mid-day while there is still sun out I that the loads are using power from battery even though solar is available. It also shows no charging is occurring from the grid or solar.

Please can someone explain to me what's going on? Is this okay? Is the unit malfunctioning or the panels not functioning correctly?

the Axpert guys (me included) only set to SBU setting 1 if there are batteries.
this should overcome your concern. 

Seems the system is functioning fine but change setting 1 and assess.

Hold Enter for 3 seconds

change setting 1 to SBU

enter

Esc

 

 

Thanks Fazil. I had setting 1 set to SOL, it was originally set to UTL.

Attached is a picture of the LCD display.

16 hours ago, raglin said:

The system is configured to use SOL as operating mode

The SOL Output Priority setting seems to be for the situation where you want your batteries as full as possible for as long as possible, to be ready for load shedding for example. It should run in battery mode through the day, charging the battery from solar and powering loads as well. It should stay in float mode all day, so you should not have the LC Display as in the photo above where the panels aren't connected to anything.

Your LC Display also shows HS (Master), meaning that you are in a parallel setting. You only mention one inverter, so that is wrong, and may be confusing things. Perhaps it's time to check your settings against @Chris Hobson's list here: Axpert Settings 1.1 .

16 hours ago, raglin said:

sometimes, around mid-day while there is still sun out I that the loads are using power from battery even though solar is available.

This could be normal. It's not unusual for the solar charge controller to slightly over-charge the battery, e.g. when the sun burts out from behind a cloud. That means the charge current will go lower, often to zero, until the battery voltage comes down to the float setting again. If you happen to look at the LC Display at such a point, you'll see current coming from the battery and little to none from the solar charger. But this situation should only last for a minute or three.

If it persists longer than that, something is wrong. Plus, as I say, having the panels disconnected as per your photo is also wrong.

Do you have your panels configured correctly for your solar charger? You didn't tell us the exact model of inverter, so it could be one with a 145 V max Voc or a 450 V max Voc; it should say which near the bottom of the large sticker (the one with the bar-code) on the right hand side of the inverter.

If you have the 450 V model and all panels are in series, then you may be exceeding the 430 V maximum MPPT voltage, and that could explain the disconnected panels, especially around midday.

Thanks @Coulomb. I'll have a look at the settings. Based on the information you provided, I suspect the installation is incorrect but I'll take a look at the settings and apply those.

11 hours ago, Coulomb said:

The SOL Output Priority setting seems to be for the situation where you want your batteries as full as possible for as long as possible, to be ready for load shedding for example. It should run in battery mode through the day, charging the battery from solar and powering loads as well.

This is exactly what I'm looking to do.

 

11 hours ago, Coulomb said:

Your LC Display also shows HS (Master), meaning that you are in a parallel setting. You only mention one inverter, so that is wrong, and may be confusing things.

There is only one inverter.

 

11 hours ago, Coulomb said:

Do you have your panels configured correctly for your solar charger? You didn't tell us the exact model of inverter, so it could be one with a 145 V max Voc or a 450 V max Voc; it should say which near the bottom of the large sticker (the one with the bar-code) on the right hand side of the inverter.

I'm not sure about the installation. The electrician that did the installation didn't give me much details about it so I'm trying to work my way through understanding it.

Thanks. Based on the info you provided, I'm certain something is incorrect, just to figure out what.

 

11 hours ago, Coulomb said:

If you have the 450 V model and all panels are in series, then you may be exceeding the 430 V maximum MPPT voltage, and that could explain the disconnected panels,

Is there any way for me test this?

Yesterday, I did restart of the system shortly after I took the picture. The restart seemed to have made the panels kick in. It looked like it was functioning the way I expected it too.

 

 

9 hours ago, raglin said:

Is there any way for me test this?

Post a picture of the large sticker on the side of the inverter, and tell us a typical PV voltage reading (use the up and down buttons till you get to a "screen" with PV volts at the left).

So I changed the setting from parallel to single. That didn't fix the issue.

Here's the pic of the sticker:

 

And this is the invert PV input voltage at the time it was it decided to stop accepting PV input:

 

I did a restart again, and it seems after the restart it tends to work correctly up until this happens. Is there some logic with the switching? Or perhaps something related to the battery that could be causing this?

 

Also took a look at the settings guide, and the only part I'm uncertain about is the battery settings..

The Voc of 104 V indicates 3S of 60 cell panels, perfect for Axperts with 145 V Solar Charge Controllers (SCCs) as yours is. So it doesn't seem to be a massive misconfiguration of the panels. There could still be some problems with the panels, causing the SCC to give up on them and declare them disconnected. [ Edit: so do the panels produce about 2.16 kW (80% of 9 x 300W) near noon on a sunny day? That would indicate that there aren't any high resistance connections. ]

The other possibility would be a rare faulty SCC.

I don't see how battery settings could cause this, but perhaps tell us the values for settings 05, 26, 27, and the cutoff voltage (I think it's about 29, AFK right now).

Edited April 20, 20197 yr by Coulomb

What batteries do you have?

What monitoring solution do you have?

What is your load like during the day?

I have the same Mecer inverter. But my solar aray doesn't show on the display. It is connected and does give power out. I have 4 X 300 watt panels connecred. 

 

Please help a newby

3 hours ago, Christoffel said:

I have the same Mecer inverter. But my solar array doesn't show on the display.

Are you saying that the whole PV icon (frame and "cells") is missing? As shown at the bottom left of this photo:

Or that the six "cells" inside the frame are missing?

In patched firmware, we use the solar panel as a mini "bar graph" to indicate the very rough solar power at a glance. One row of "cells" means about 1 kW ± 0.5 kW, two rows means 2 kW ± 0.5 kW, and 3 rows (as above) means 2.5 kW or more. With your 1200 W of panels, you'd only expect around 75% of that (900 W) in good conditions, so that would be one row. In less than good conditions (say before 9am), you'd get less than 500 W, so no cells would show at all.

To find out if you have patched firmware, scroll through the various display options using the Up button till you get to a screen with either "U1", "LC1" or "LF1" in the left set of alphanumerics. If it's "U1", then you have factory firmware (not patched). If it's one of the other options, it's patched.

If you didn't re-flash the firmware yourself, i.e. it came with patched firmware, this is a sign of a clone. I've not seen a clone claim to be one of the legitimate brands like Mecer, but I suppose anything is possible these days.

Edited November 18, 20196 yr by Coulomb

There is nothing there

So can I load the software on my laptop and update the firmware?

Where can i get the firmwareThere is nothing there

On 2019/11/18 at 11:05 PM, Christoffel said:

So can I load the software on my laptop and update the firmware?

No, unless you can get an even more up-to-date firmware from your supplier. 74.40 is the latest firmware available, and it only became available on this forum in the last few weeks.

On 2019/11/18 at 7:33 PM, Christoffel said:

But my solar array doesn't show on the display. It is connected and does give power out.

When you say "does give power out", do you mean power from the inverter's output (supplied by the battery or AC-in), or from PV?

In particular, what does the "PV voltage" screen show?

I note that your LC Display shows "HS". This is telling you that this is a MAster in a set of paralleled and/or 3-phase machines. If you have only one machine, you need to change the output mode to SNG (SiNGle machine). See FAQ question 4. I note that showing "HS" has been implicated in at least one problem on this forum.

Edited July 9, 20206 yr by Coulomb

I look at FAQ 4. My inverter is a stand alone.

The PV gives out Volts on the inverter. This morning before 6 it was 40 v. I measured it specially. When I go thrue the settings with up or down button it shows nothing (the PV voltage)

When eskom is switched on at my main db board the inverter runs the house and charges batteries. I run the house during the night from my batteries and eskom's power is switched off at night. Everything is working fine except it doexnt show my solar array (4× 300 watt panels)

I talked to mustek yesterday.  The guy also told me it's the newest firmware

I did change segging (28) but don't get a SnG in the centre. There is nothing now. And still no solar array. 

The inverter switched back to [HS].

STILL NO SOLAR PANELS ON DISPLAY

20 hours ago, Christoffel said:

When I go thrue the settings with up or down button it shows nothing (the PV voltage)

Ok. So you either have no PV input, or your Solar Charge Controller (inside the inverter-charger) is faulty.

Can you put a multimeter on the PV-in terminals? That will likely tell you which problem you have.

19 hours ago, Christoffel said:

I did change segging (28) but don't get a SnG in the centre. There is nothing now.

OK, that's good, that's what you want. No SnG will appear (there are only two 7-segment positions there anyway).

19 hours ago, Christoffel said:

The inverter switched back to [HS].

? That's strange.

Did you change setting 28 back to PAL?

What does setting 28 report now?

If I put a multimeter to the PV terminals on the inverter I get175.2 volt. But 0 amps

40 minutes ago, Christoffel said:

If I put a multimeter to the PV terminals on the inverter I get175.2 volt.

The maximum PV input voltage for these inverter-chargers is 145 V. They produce zero power above this voltage.

You mentioned 4 panels. I assumed that you would wire these 2S and 2P (two paralleled strings of 2 panels in series). It looks like you have them wired all in series.

So you just need to rewire them. You'll need fuses for each string.