1 minute ago, Jacques Ester said:

I also have 12 x 335W panels connected.

Getting between 2300w and 2500w. 2 days ago I got 3kw for about 2 hours🤔

Running 3S4P

Drives me crazy🥴

Yip, if you are running 3S then that does not solve the issue as well.  but it is frustrating! Loosing 1000+ Watts is crazy if you ask me! I have even gone as far as providing extra cooling for the King now it does not go over 38 'C but still does not make any difference. 

 

Just thinking out loud here. More questions than answers. As always I'm open to correction by those who know better.

The inverter is rated at 5000VA/5000W.

Now is there any significance to the fact that in the image below someone is pushing an apparent power of 4460VA, 6413VA and 4505VA. That's basically near the full rated capacity of the inverter in terms of VA, or even surging above it.

What is the rating for power factor on this inverter? My Deye for example is rated at 0.8 leading to 0.8 lagging. Here I'm seeing a power factor of (2167/4460=0.48), (2176/6413=0.33) and (2378/4505=0.52) or thereabouts.

Where I'm headed with this is to ask if it makes any difference what type of loads you are running? If you turn off all other plugs and run a purely resistive load of around 4kW through the inverter's MPPT, let's say a kettle and a toaster together, will the inverter be able to push closer to its rated MPPT power in terms of Watts? For that matter, what happens if you turn off all the plugs and the mains, and you only charge the battery off from the solar? Can you charge near to 4kW from the panels?

On the flip side, if you are running highly inductive loads, are you doomed to living with a lower real power generation from solar? Will the reactive power be drawn from and returned to the battery? is it traded with the grid? Does the King inverter's AC-DC-AC conversion step preclude it from passing through reactive power components from the grid like a GTI or maybe the Axpert MKS could?

Edited October 6, 20223 yr by GreenFields

2 hours ago, GreenFields said:

 

Where I'm headed with this is to ask if it makes any difference what type of loads you are running? If you turn off all other plugs and run a purely resistive load of around 4kW through the inverter's MPPT, let's say a kettle and a toaster together, will the inverter be able to push closer to its rated MPPT power in terms of Watts? For that matter, what happens if you turn off all the plugs and the mains, and you only charge the battery off from the solar? Can you charge near to 4kW from the panels?

 

For me it does not matter, if I turn off all plugs and run a resistive load or only charge battery, I have never passed 2400Watts on my system.

3 hours ago, GreenFields said:

Now is there any significance to the fact that in the image below someone is pushing an apparent power of 4460VA, 6413VA and 4505VA. That's basically near the full rated capacity of the inverter in terms of VA, or even surging above it.

As long as the time above 5000 VA is short, it should not matter too much. Imaginary power mostly travels to and from the load back to the bus capacitors; not much of it should end up coming from the battery. But 6000 VA is still 120% of the inverter's rated continuous capacity, so that's an overload. In theory, the inverter should be able to provide up to 10 000 VA for a few seconds; in practice, it probably won't.

3 hours ago, GreenFields said:

Does the King inverter's AC-DC-AC conversion step preclude it from passing through reactive power components from the grid like a GTI or maybe the Axpert MKS could?

If the King is in bypass mode, then the utility can provide the extra VARs (Volt·Amperes Reactive). But usually the King will be in line mode, where indeed the double conversion will prevent it from having the utility act as a buffer. But my recent understanding is that even in bypass mode, 6000 VA is considered 120% of rated VA, and hence is an overload situation, which will eventually result in a fault code. My understanding is that all Axpert models have this limitation, not just Kings.

On my Axpert King 4000/5000 system i have seen a max of 1.7kw earlier in the year but since then its always around 1.3/1.4kw and last week it went to 1.5kw.

i have tried various loads with the kettle, oven, hairdryers, aircons etc or just to charge the battery and it does not go higher.

It runs in SUB mode but on occassion i have used SBU and always in the same range.

on setting 16 i use SLB/UDC and have tried other settings with no change.

I have a 2s4p 480w panel setup. will be adding another parallel pair at month end .

I have a 4s3p setup with 12 x 135AH agm batteries.

Max i have seen the batteries charge at was around 26/28amps and the inverter is set to 60amps for max charge on setting 02 and 2amps for setting 11 for utility.

seeing more and more posts with reference to pv output being lower than expected and it seems to be a issue.

On the forum in a previous post and while back it was suggested my panels could be the cause being cheap chinese ones.

A few months ago i tried 2 x500w solar panels from a friend to compare to my chinese panels but wasnt much in it to blame my panels as the culprit. was getting 300/310w from 1 x 2s string and his panels 325/33w with voltage around the 64-68v mark.

 

@razzor13bt

Did you ever measure with a voltmeter (on DC) between the "+" and ground (PE) and the "-" and ground (PE) of your strings?

The DC measurement should be close to 0 Volts.

I had simmilar issues with a Voltronic licensed under EaSunPower.
I had 18 x 385w Panels in 2SP config and I could see peaks of 4,5-5kw.

Then I added 2 more panels on each string and voila ... power went up to 6kw. Seems Voltronic units don't like voltage lower than 360V.

Edited October 6, 20223 yr by Jaxone

6 hours ago, Jaxone said:

I had simmilar issues with a Voltronic licensed under EaSunPower.
I had 18 x 385w Panels in 2SP config and I could see peaks of 4,5-5kw.

Then I added 2 more panels on each string and voila ... power went up to 6kw. Seems Voltronic units don't like voltage lower than 360V.

How many panels are you using to get the current peak of 6kW?

11 hours ago, geert said:

@razzor13bt

Did you ever measure with a voltmeter (on DC) between the "+" and ground (PE) and the "-" and ground (PE) of your strings?

The DC measurement should be close to 0 Volts.

are you reffering to testing the panels in open circuit ? 

if i measure voltage on each string in the combiner box with all fuses isolatated i get very similar voltages within a volt or 2 .

when connected to the inverter and i measure each string under load the voltages are also very similar with a volt or 2.

if i check the wattage on the inverter display with 1 string at a time. i get very similar readings for each string.

when you say measure + or - to ground(PE) are you meaning the actual frame of the panels ?

If yes, then i have not done that but could check it over the weekend.

12 hours ago, geert said:

@razzor13bt

Did you ever measure with a voltmeter (on DC) between the "+" and ground (PE) and the "-" and ground (PE) of your strings?

The DC measurement should be close to 0 Volts.

My one inverter has 2 strings of 7 x 325W panels and the other inverter 1 string of 7 x 330W panels.

I measure about +40V between the string + and earth and -184V between the string - and earth. Is this a problem?

Here by us in South Africa we have to connect the panels with an earth wire to each other on the earhing point of the PV panel frame. I used 6mm2 between the panel. Then we have to connect that earth from each PV string to the AC electrical earth of the house in the AC distribution box. I used 10mm2 to connect the strings together and to the AC earth. The inverters are also earthed to the same AC earth. The earths of the batteries in the battery cabinet are also connected together and also connected to the same AC earth. The inverters and the batteries are connected together with a 10mm2 cable to the AC earth.

For lightning protection, I earthed the solar panels via a 16mm2 cable to an earth spike as well. I actually have to earth spikes, connected together with bare copper wire, all under ground, to increase the area of the earth.

In addition, I have DC surge protectors in each of my two DC combiner boxes.

4 hours ago, Scorp007 said:

How many panels are you using to get the current peak of 6kW?

I do not have the EaSun anymore, changed to a Deye 3 Phase.

9 minutes ago, Giel said:

My one inverter has 2 strings of 7 x 325W panels and the other inverter 1 string of 7 x 330W panels.

I measure about +40V between the string + and earth and -184V between the string - and earth. Is this a problem?

Here by us in South Africa we have to connect the panels with an earth wire to each other on the earhing point of the PV panel frame. I used 6mm2 between the panel. Then we have to connect that earth from each PV string to the AC electrical earth of the house in the AC distribution box. I used 10mm2 to connect the strings together and to the AC earth. The inverters are also earthed to the same AC earth. The earths of the batteries in the battery cabinet are also connected together and also connected to the same AC earth. The inverters and the batteries are connected together with a 10mm2 cable to the AC earth.

For lightning protection, I earthed the solar panels via a 16mm2 cable to an earth spike as well. I actually have to earth spikes, connected together with bare copper wire, all under ground, to increase the area of the earth.

In addition, I have DC surge protectors in each of my two DC combiner boxes.

I would say it is a big problem. Try to remove the earth wire from panels and see if you have any significant change.

@Jaxone why would this be a big problem? I need some explanation to understand why I should change it.

The wiring was done according tot South African wiring standards in order to get what we call here an electrical Certificate of Compliance (COC).

6 minutes ago, Giel said:

@Jaxone why would this be a big problem? I need some explanation to understand why I should change it.

The wiring was done according tot South African wiring standards in order to get what we call here an electrical Certificate of Compliance (COC).

That I understand , but if you have 184V between panels and earth , this means you have a 184v leak from panels to earth.

I disconnected the solar string from the inverter with the DC isolator in the PV combiner box. I then measured 3V DC between PV+ and earth and 8V between PV- and earth.

6 hours ago, Jaxone said:

That I understand , but if you have 184V between panels and earth , this means you have a 184v leak from panels to earth.

Not always the case. It is the inverter causing this reading in the way it converts power from DC to AC. As mentioned if the inverter is disconnected from the panels this voltage goes away. I found this out while working on panel connections and could touch my + and -  with not even a tingle. As long as both are not touched. I had to work during good sun due to the time taken for the task.

On 2022/10/06 at 10:08 PM, geert said:

@razzor13bt

Did you ever measure with a voltmeter (on DC) between the "+" and ground (PE) and the "-" and ground (PE) of your strings?

The DC measurement should be close to 0 Volts.

Hi

Did the testing on the 4 strings.

Got the following.

All strings disconnected at fuses and reconnected one at a time and tested.

St 1. + 20v

St 2. + 0v

St 3. + 0v

St 4. + 19.5v

St 1. Gnd - 0v

St 2. Gnd - 0v

St 3. Gnd - 0v

St 4. Gnd -18.5v

Voltages pretty much match when string 1/2/3 are connected.

St 1. + 21v

St 2. + 21v

St 3. + 20.5v

St 1. Gnd -5.7v

St 2. Gnd -5.6v

St 3. Gnd -5.8v

With all connected I get a change in voltage.

St 1. + 22v

St 2. + 21.6v

St 3. + 22v

St 4. + 22v

St 1. Gnd -14v

St 2. Gnd  -14.3v

St 3. Gnd  -14v

St 4. Gnd -14.1v

@razzor13bt, if I remember correctly, you have 4 strings of 2 x 480W panels. The Vmp per panel is 41.4V as per your post on 29 June. If that is correct, then you should be getting around 80V DC between PV+ and PV- per PV string. Your Imp current per string should be about 11.6A as per the specification. The total power per string is 960W and the total PV power for the 4 strings should be 3840W. My estimate is that you should be getting between 70 to 80% of this or up to 3100W. If you multiply this by an average of 5.5 sun hours per day for Gauteng, then you be producing around 17 kWh (units) per day.

If "Gnd" above means "PV-", then if you measured between PV+ and earth (at the bottom right of your orange surge arrestor in your PV combiner box as posted by you on 17 June) and again PV- (Gnd) and earth on your PV combiner box, with the panels connected, the total voltage per string seems a bit low. For instance St 1 = 22 + 14 =36V, St 2 = 21.6 +14.3 = 35.9V, St 3 = 22 +14 = 36V and St 4 = 22 + 14.1 = 36.1V. Is this correct? If it is correct, I think this is below the operating range of the King, which is 60 to 115V DC. Previously you stated that you measure around 64V using 2 x 500W panels from a friend of yours. Even that 64V is close to the lower limit of the King.

This means that either the panels are under performing or you have a wiring issue on each string. I prefer to use 6mm2 solar wire between the panels and the PV combiner to reduce losses, but using 4mm2 should be fine. The MC-4 connectors should be properly secured/mated. You can feel the connectors and the wiring to find any hot spots. If it is warm, you should investigate.

I would remove four panels from two strings and test them on the ground or if you can, connect them together on the roof, but first disconenct it from the inverters. Put these foure panels in series. It will be 1920W and should produce around 160V when conencted. be careful not to touch the wires as this can be a shocking experience. You can connect a 2kW geyser element as a load. Measure the current using a clamp on amp meter while mesuring the voltage at the same time. Mulitply the current and voltage to determine the watts. Just be careful, do this quick as that element will get very hot. If you do not get close to 1920W, then try to change the angle of the panels and make sure they face to the sun to try to increase the power. This way you can confirm whether the panels are actually producing what they should or whether they are below par.

10 hours ago, Giel said:

I would remove four panels from two strings and test them on the ground...

That sounds very dangerous to me; I would not recommend it. I doubt that the geyser would happen to be the right load to get anywhere near MPPT from the panels, so it may not be terribly conclusive anyway.

Coulomb, why is it dangerous? I have done this test with a 3kW geyser element judt yo see if the element will hear up and had no issues?

Just all that UV with the DC arcs, things getting very hot very quickly... For someone with less experience, there is so much to go wrong. 

Any other simple/easy ideas to load test the panels in order to determine their yield?

when i have extra hands available . i will look at testing each panel.

Have 2 more panels arriving at month end, so will do it then.

from 8 x 480w panels will go to 10 x 480w panels =4800w - will allow for 20% oversizing from the 4000w the King is specced at.

Hope to get a bit more solar production during the day.

Long term i hope to change out the King to another brand .

Looking at Solis or sunsynk if budget allows.

 

 

 

On 2022/10/09 at 10:33 AM, razzor13bt said:

@razzor13bt

Maybe in stat of testing your solar panels, you could borrow another inverter somewhere and test, this will split your possibilities in half 

On 2022/10/11 at 9:44 AM, razzor13bt said:

Hope to get a bit more solar production during the day.

Any improvements seen yet?