Yes problem solvedIf! The PV out put voltage to high! I must put 2 in parallel.  And in series. 

My amps is still low. Shows 0 on inverter. But that was 5 this morning. I'm working till 1 then I'll change them 

 

Thanks for the help.

My mercer 5kva is not charging from the solar panels but can charge from the mains and there is no error message. The power is coming from the panels.

On 2019/04/20 at 12:13 PM, raglin said:

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..

Did you ever come right? My system (Axpert/Mecer 5KVA, 9x330W panels - 3x3 I think, Pylon 3000US 3kW) has been doing the same intermittently pretty much ever since it was installed.

Had a guy come check last week who thought maybe it was the solar holders since they were a but wonky. Replaced them, but it happened again today, so that wasn't it. 

Also the voltage hovers around 120 which is higher than would be expected since those panels are supposed to give off 35V each so 3 of them in series would be 105V.

Cutting off the PV completely and waiting for 30s or so, then reconnecting it seems to fix it for me (previously I would restart the whole inverter, but this is easier).

Oddly enough, after cutting off the PV the voltage display on the inverter slowly drops from 120V down, but it takes a long time to get to 0V. Don't know if that's normal or not.

 

Anyway, if you found a way to fix it, let me know. I'll update this post as well if I find new information.

13 hours ago, SolarFrans said:

Also the voltage hovers around 120 which is higher than would be expected since those panels are supposed to give off 35V each so 3 of them in series would be 105V.

You didn't say what model of 330 W panel. The first Canadian Solar 330 W panels I found specifications for have a Voc of around 40 V, so you'd expect 120 V under no or light loads. Vmp is around 34 V (at 25°C and 1000 W/m²), so that's more like 102 V or lower when running full power.

13 hours ago, SolarFrans said:

Cutting off the PV completely and waiting for 30s or so, then reconnecting it seems to fix it for me (previously I would restart the whole inverter, but this is easier).

Do you perhaps have one of the inverter models with a PV Voc max of 115 VDC? Most of the low voltage SCC models have 145 VDC max, but we've seen a few with 115 VDC.

13 hours ago, SolarFrans said:

Oddly enough, after cutting off the PV the voltage display on the inverter slowly drops from 120V down, but it takes a long time to get to 0V. Don't know if that's normal or not.

I believe that's normal. There are four capacitors at the PV input, which hold the PV voltage somewhat steady when the current waveform is chopping on and off. When not charging the battery / supplying loads, the only load is the electronics, which draws only about 2 W, or probably much less when not active. That would cause the reported voltage to slowly sag from whatever the panels charged the capacitors to before being disconnected, towards zero over many seconds or tens of seconds.

Good evening.I have the same problem with the MECER inverter as this gentleman.But my PV input V is 132,5V at the PV input on the inverter. i have 9 panels of 365W each, 3x 3 strings.

132,5V at midday.But no solar panels shows on the display,the setting for on SET 01 = SON.The 2 x 2.4kW Pylontech batteries also switches off after 5min.When I measure the Voltage at the Fuse Isolator terminals it is 49,99V, after AC is restored then the SOC on the Pylontech shows full(All green LEDS on).

7 hours ago, Solarsmit said:

132,5V at midday.But no solar panels shows on the display

That's quite high, already into the power derating zone (130 - 145 V). I'd say your panels are 72-cell, whereas Raglin's seem to be 60-cell. Note this post:

On 2019/11/22 at 3:04 PM, Christoffel said:

Yes problem solvedIf! The PV out put voltage to high!

I'd say you need to rewire to 2S. @raglin's problem seems to be different to yours.

It may be that the newer SCC firmwares won't allow SCC charging with more than a certain voltage; it used to be that they would start with a little under 145 V (at 145 V, the power is derated to zero). I don't have access to SCC firmware later than version 04.10 (machines have been delivered with 04.12 for years now).

Thanks for the info.But it still baffels me.I did the string calculations with the max PV inverter voltage of 145V and it indicated that I can use 3 max in a string.

Question : Do you use the max inverter PV input voltage or the MPPT max V of 115V?

1 hour ago, Solarsmit said:

But it still baffels me.I did the string calculations...

A lot of people seem to get this wrong.

1 hour ago, Solarsmit said:

Question : Do you use the max inverter PV input voltage or the MPPT max V of 115V?

You use the panel Voc to make sure it's below 145 V at your coldest mornings; I usually use 0°C, but some areas might need lower. As a rule of thumb, you can add 7% to the nominal 25°C value (i.e. use Voc x number-of-panels-per-string x 1.07).

You should also check that Vmp comes out below 115 V; that you can probably do at 25°C (just use the nominal ratings).

Thank you Coulomb.Then my calculations was correct.But the solar panel on the inverter does not show.

I contacted MECER,waiting for an answer.Will keep you up to date.

I have also bought a GROWATT 5kW inverter.I struggle with the LiFePO4 setup.They state I must select the Li in step 5 then it jumps to step 36.There is a selection of Protocols,when I select the first protocol and change it from 

L0 2 to L1 2 then the inverter goes into a fault mode.

Any ideas?

8 hours ago, Solarsmit said:

But the solar panel on the inverter does not show.

I believe that it won't show if the panel voltage is too high or too low.

Does it come on at say 8am when the panels have warmed a bit but are not yet in full sun?

What is the PV voltage at that time?

It is a client's installation.

Good day.I have a Growatt inverter 5Kw, I want to use Watch power to communicate with the inverter but when I insert the USB cable then my laptop inform me that it does not recognize the USB device.

What else can I do?

On 2019/11/21 at 3:34 PM, Coulomb said:

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.

On the 5KVA Mecer inverter with 145v solar. You chould have a series of 3 panels not more. Your Panels range between 30 - 40 v per panel (estimate) 3 panels should give you around 105 - 120v. If 4 conencted in series your inverter will go into fault mode as you exceeding max Charge V on your Mppt. 2x panels could work but your will be switching your mttp on and off from pushing out low voltage. 

 

On 2020/12/30 at 6:56 AM, Avi said:

On the 5KVA Mecer inverter with 145v solar. You chould have a series of 3 panels not more.

Experience has shown that this is only true if the panels are 60-cell. More commonly these days, they are 72-cell (sometimes even more, not counting "half-cells"). 145 V is an absolute maximum rating, it can't operate at that voltage. It turns out that at higher panel voltage, the Solar Charge Controller gets significantly hotter, so even if you "get away with" say 130 V (the maximum before the SCC starts derating), it will likely overheat and derate or switch off.

That's why my signature warns never to use 3S of 72-cell panels with this type of SCC.

I haven't been monitoring this for a while, though I did manage to get my settings right.

On my setup, it was related to incorrect voltages set for program 12 and 13, this cause the inverter to keep switching between normal operation (charging from solar, powering loads) and battery mode (no charge from solar, and only powering loads).

4 hours ago, raglin said:

I haven't been monitoring this for a while, though I did manage to get my settings right.

On my setup, it was related to incorrect voltages set for program 12 and 13, this cause the inverter to keep switching between normal operation (charging from solar, powering loads) and battery mode (no charge from solar, and only powering loads).

Hmm isn't that's odd? Shouldn't those just control switching from solar/battery to grid and back? Not from solar-only to battery?

At least, my manual says:

12 - Setting voltage point back to utility source when selecting "SBU priority" or "Solar first" in program 01.

13 - Setting voltage point back to battery mode when selecting "SBU priority" or "Solar first" in program 02.

 

But out of curiosity, what voltages did you set for these programs now? What battery are you using?

(I'm dying to get a similar problem solved. I'd bring it in for repair, but I'm afraid they'll just change a few bits and pieces and tell me it's fixed without actually attempting to reproduce the problem and test that it's actually fixed after the repair...)

 

Thanks!

On 2020/12/31 at 4:02 AM, Coulomb said:

Experience has shown that this is only true if the panels are 60-cell. More commonly these days, they are 72-cell (sometimes even more, not counting "half-cells"). 145 V is an absolute maximum rating, it can't operate at that voltage. It turns out that at higher panel voltage, the Solar Charge Controller gets significantly hotter, so even if you "get away with" say 130 V (the maximum before the SCC starts derating), it will likely overheat and derate or switch off.

That's why my signature warns never to use 3S of 72-cell panels with this type of SCC.

Could this be the problem in my case as well then? The reported PV voltage goes up to ~125V, but it seems that on warm, sunny days, the unit does tend to switch off the SCC around 1pm. Could be that the voltage + outside temperature pushes it over the edge?

Of course many other things also happen on warm, sunny days, such as the battery being fully charged before noon, the solar panels providing more power, etc. But just wondering if this is worth investigating?

I wouldn't know how to wire 9 panels in series of just 2 panels, though....? Can I have 4 strings of 2 panels and a single panel all in parallel?

 

Thanks again,
Frans

3 hours ago, SolarFrans said:

I wouldn't know how to wire 9 panels in series of just 2 panels, though....? Can I have 4 strings of 2 panels and a single panel all in parallel? 

No, to rewire as 2S you have to choose between 8 and 10 panels (i.e. wasting one or adding another one). It's possible that going down to 8 panels will actually result in more usable energy, at least in some circumstances.

12 hours ago, SolarFrans said:

But out of curiosity, what voltages did you set for these programs now? What battery are you using?

So had prog 1 set to SOL, only switch to eskom if it goes lower that 12

and prog 16 to OSO (only solar). I can't remember what 12 was, but I'm sure it was to high.

And I think prog 13 was too low. It would charge up, switch to battery mode, deplete, then go back to charging from solar. Now that I'm trying to remember, I think the float and bulk charge voltages also impact how prog 13 functioned. I'm probably completely wrong, those are what I fiddled with after reading the internet, manuals, and the nifty guide from this forum.

Right now, I have 2x4.8kw, 100Ah batteries.

I have prog 1 to SBU

prog 12 to 48v (still tweaking, though this seems to be working sufficiently, given the evening and loadshedding considerations)

prog 13 to 54

prog 16 to OSO

prog 26 (bulk) to 53.2

prog 27 (float) to 53.0

1 hour ago, raglin said:

prog 26 (bulk) to 53.2

prog 27 (float) to 53.0

The recommended (by the consensus of this forum, not the manufacturer, they don't know what they're doing 😐) values are 52.5 V and 51.8 V respectively. The higher voltages in conjunction with overshoots can lead to panic switching off by the BMS, which isn't good.

1 hour ago, Coulomb said:

values are 52.5 V and 51.8 V respectively.

thanks, I'll update accordingly.

On 2021/01/15 at 11:09 AM, Coulomb said:

The recommended (by the consensus of this forum, not the manufacturer, they don't know what they're doing 😐) values are 52.5 V and 51.8 V respectively. The higher voltages in conjunction with overshoots can lead to panic switching off by the BMS, which isn't good.

I've set my bulk and float voltage to these values and so far the inverter is doing a lot better: it's no longer switching off the PV input when the battery is full! This issue has plagued me ever since we got our solar installed and this seems to have finally fixed it!

@Coulomb my man, if I'm ever in Brisbane I'm buying you a big-ass beer!

Pls explain the solar vs Eskom power?

is the change over automatic?

we are considering 8kw Mercer inverter with 2 x 3.6k Pylontech batteries 3000c

is this good setup?

20 hours ago, Nicolas4000 said:

Pls explain the solar vs Eskom power?

is the change over automatic?

we are considering 8kw Mercer inverter with 2 x 3.6k Pylontech batteries 3000c

is this good setup?

The Mecer (Axpert) uses battery voltages as thresholds for switching to solar/grid. E.g. I've set my lower threshold to 48V and upper to 49V. If the voltage drops below 48V (which is normally when the battery has about 10-20% charge left, but read on), it will switch to grid (Eskom). If the voltage comes back over 49V (like when the sun comes up and the battery starts getting charged again), it will switch back to solar+battery.

However, and this is the downside of the Mecer/Axpert inverters: a voltage drop on the battery also happens when you switch on an appliance that draws a significant load, like a kettle. This tends to temporarily drop the battery's voltage below 48V as well which then causes the inverter to think the battery is nearly discharged and switch to the grid. Once the kettle switches off, the battery's voltage recovers and the inverter switches back to solar+battery, but now you've run your kettle on grid power instead of solar/battery.

The alternative is to set the battery threshold really low, like 44V, and let an external "something" do the switching to/from grid using the actual battery state of charge that it gets from the battery's BMV. That "something" can be a Raspberry Pi mini-PC with ICC software on it, and I used this for a while and it worked really well when it did. But it stopped working for me and ICC's customer support appears to be non-existent these days, so buyer beware.

An all-in-one solution, i.e. an inverter that can read the SOC values from the Pylontechs itself and switch on actual SOC instead of battery voltage, is a lot more expensive, so you need to decide if it's worth it for you. If you want to absolutely minimize the amount of power you draw from the grid (with 2 Pylontechs you could theoretically run completely off-grid in the summer, assuming you already have a solar geyser and you can keep your nightly consumption to about 400W i.e. just a fridge and some phone chargers), then the Mecer isn't the right inverter for you and you'll need to look at a more feature-rich model (everyone seems really excited about the Sunsynk). However, if you want to just reduce your power consumption and protect against load shedding, this setup should do just fine.

 

In the case of load-shedding, the Mecer/Axpert won't try to switch to the grid as it detects that there's no voltage there, so it will keep using solar+battery even when battery voltage drops below 48V. So as long as you've got charge left on your Pylontechs, you're good.

There's another setting, the battery shut-off threshold (usually set a lot lower at like 45V), and the inverter *will* switch off when that is reached. Also, the Pylontechs shut themselves off out of safety when the SOC drops really low, like <5%. That's what would happen if your load shedding were to last longer than your Pylontech's charge can hold out for, and since your inverter is then running off of the battery, it will switch off, too. I've noticed that in that case the Axpert doesn't switch itself on again when power on the grid returns, you need to hit a red button on the Pylontechs which will switch them on again, at which point the inverter gets power again and switches on as well; then once it's started up it should pick up that the battery charge is low and switch to grid.

You can always start with the Mecer and upgrade to a higher-end inverter in a year or two and sell the Mecer off to someone else just starting out.

 

Hope this isn't information overkill 🙂 Let me know if anything's unclear or you want even more details.

 

~ Frans