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Hi new member here looking for advice. I’m having a nightmare with my installer and Solis and wondering if anyone can come back with any ideas.
5kw solis hybrid inverter, 7kw BYD battery and 6.3KW 20x 315w panels on the roof (two strings). system points SSE at 45 degrees.
On very sunny warm days the inverter shuts down all generation, current and voltage drop for about an hour as sun is highest in the sky and system then comes back online. I think it’s hyper clipping but Solis and installer disagree (Have no idea say it’s impossible) and want me to video it and check voltage off each strung next time it happens with a MM. I think the panel are producing too much power on these days over 6.5kw even though that would assume max manufacturing tolerance etc are met and the inverter is shutting down as it’s only rated max 6.5kw.
Anyone ever experience this before any ideas? Inverter has been swapped already issue remains. I’m asking them to install the new released 7kw Solis inverter to see if it fixes the issue or temporarily disconnect two panels and see if it goes away. System only installed since last September so this summer is the first one and a nightmare so far of inverter changes and arguments. See photos of the issue occurring.
 

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Thanks Marconi.
I have checked this and the inverter is in a cool plant room so not an issue the temperatures stay well below the threshold at all times per the monitoring app. Wish it was the problem but this has everyone stumped at the installer and Solis. I suspect Solis know what it is but won’t agree as this setup is common in Ireland and if they admit it could lead to a lot of future claims.

file:///C:/Users/Dom/Downloads/Solis-1P-(1-5K)-4G_V1.pdf

Re: Section 4 - Installation.

'On very sunny warm days....'

I wonder if the inverter is overheating because of inadequate ventilation? But, you don't report an OV-TEMP fault. The reference indicates the chassis of the inverter can reach 75C.
 
Hi - when the Invertor turns itself off does it record a Reason Code or some such? Is there a fault log?

Ive just read the manual, and there’s a list of fault codes ... unless you are saying it turns its self off but it thinks everything is fine and operational so there is no code etc?
 
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Hi Wilko, it doesn’t turn off it only stops accepting anything from the array. The power from the battery still comes through the inverter to the house while this is occurring. No fault codes or alarm messages at all on the inverter. (Apart from a code batname-FAIL that’s been there since day one even though inverter is setup for BYD battery installed but I’m told it’s not a problem) Solis say this cutting off the array is impossible and something must be tripping in the house but it most definitely is not. The inverter seems to be going into some sort of protection mode due to too much power from the roof or as I suspect hyper clipping as the voltage is outside of the parameters allowed so it shuts down the incoming power from the PV array. At a loss to figure this out they already installed a replacement inverter and no difference. I’m still under warranty but as the issue only occurs on the clearest sky sunny days of summer and summer is over I may not see it again until next year. Occurre approx 20 time this summer so far. Would be great if someone had seen this before or had the same issue.

Hi - when the Invertor turns itself off does record a Reason Code or some such? Is there a fault log?
 
Have you or your installer checked the inverter is set to the correct country code? I've had inverters supplied which were pre-configured for another country which has led to this kind of problem. (Solis was not the manufacturer though).
 
Are you familiar enough to go through the config files? Perhaps take a few pics ... There are many user configurable bits and it does sound like you are hitting a limit and shutting down.
 
Maybe..... The absence of fault codes is because the inverter is fault free and operating as designed. As does the replacement.

On really sunny days there is peak PV generation for long period of say 5kW. Some or all of this power is exported to the grid. Let me assume for now it is all exported.

The Solis inverter computer monitors the grid voltage to detect its presence and to act if the voltage is too high or too low. If it acts it is to disconnect the inverter from the grid terminating the export of power.

The Solis inverter measures the grid voltage and if over a rolling say 5 minute period the average voltage is greater than say 255V it acts and disconnects the inverter from the grid. Also, if the grid voltage exceeds say 260V momentarily it will also disconnect from the grid. These time periods and voltages can be preset and are sometimes mandated by the DNO to safeguard the grid's power quality with respect to voltage. It could be quite a problem when a few/many solar PVs are grid connected on the same local distribution line.

The inverter cannot actually measure the grid voltage Vg - see my attached diagram - because it is connected to the grid by cables with resistance - Ri, Rs and Rd.. To export power the inverter voltage Vi must be greater than Vg. Thus when exporting power the inverter output voltage Vg depends on the grid voltage at the time Vg and the volt drop between the inverter and the grid which is I x (Ri + Rs + Rd).

At peak power output of 5kW the current I is circa 5000/250 = 20A.

The voltage drop is of the order Vd = 20 x (Ri + Rs + Rd). If the total resistance was say 0.2 Ohms then the volt drop while exporting 5kW at 20 A would be 20 x 0.2 = 4V. The installation may need the inverter cable (Ri) to be upgraded to reduce its effect on Vd and thence Vi. Not so easy to do this for Rs and Rd.

On a lightly loaded grid in summer the grid voltage Vg may well be high. On very sunny days with high levels of export Vi monitored by the inverter which is Vg +Vd may break one of the inverter voltage checks - rolling average or momentary excess. And it disconnects for a while.

There is also another 'feature' in the solis inverter which may be enabled. This is the power-voltage reduction profiler.

See Page 33 of the Manual of :

https://www.cclcomponents.com/solis-4g-5kw-solar-inverter-single-phase-2-mppt

where you can see the volt-watt diagram. See how the power reduces linearly when the voltage exceeds V3. V1, V2, V3 and V4 and the associated %power output may be preset. But I note the default settings are 100% for each of V1-4 so unless someone has set this feature up I do not think it is having any effect.

What to do?

1. Examine the size/csa and length of the cabling between the ac output of the inverter and the intake. Do a volt-drop calculation for I = 20-25 A. Is it 'excessive'? Could you tell us the length and csa in mm2?

2. Take some voltage measurements Vi, Vd(at intake) and Vg (disconnect installation from grid to do this). Do this on cloudy days, normal sunny days and peak sunny days. Do the voltages suggest the inverter is working as designed to disconnect if Vg is too high the rules for which I described earlier? Is their high voltage drop between intake and grid or inverter and intake? Ampclamp the ac output cable to measure I.

3. Check tightness of all connections.

4. If you have a three phase supply check that the inverter is connected to the phase with the highest loading.

5. Check to see that phase to phase voltages are about the same.

6. Check phase to Neutral voltages - this helps to discover a low conductance neutral.


I have to finish for now but I noted that two pieces of data the inverter monitors (and records?) are Vg and I - perhaps you could keep an eye on it?

Or something along these lines.

Errata - in my diagram voltmeter Vg should be at Tx - but you spotted that already.
 

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Are there other/many other solar pv installations in your locality and of most relevance perhaps connected to the same power distribution lines as your home? It could be 'they' are 'pushing' you off the grid by raising your supply phase voltage up by their pv power exports.
 
Wilco thanks yes im comfortable doing that any specific info you think woud be usefull?

The data logger can be looked at to see the paramnaters of any day this happed so i can send screen shots if its helpfull just there is a lot of info in there so if you know what i shoud send let me know

Are you familiar enough to go through the config files? Perhaps take a few pics ... There are many user configurable bits and it does sound like you are hitting a limit and shutting down.
[automerge]1598557224[/automerge]
Marconi thanks for this it includes a lot of info so I think i will send it to the installer and ask him to check per your ideas.

The inverter i have is the hybrid model not he one you linked to see below although seems that it is almost identical in operation.


Maybe..... The absence of fault codes is because the inverter is fault free and operating as designed. As does the replacement.

On really sunny days there is peak PV generation for long period of say 5kW. Some or all of this power is exported to the grid. Let me assume for now it is all exported.

The Solis inverter computer monitors the grid voltage to detect its presence and to act if the voltage is too high or too low. If it acts it is to disconnect the inverter from the grid terminating the export of power.

The Solis inverter measures the grid voltage and if over a rolling say 5 minute period the average voltage is greater than say 255V it acts and disconnects the inverter from the grid. Also, if the grid voltage exceeds say 260V momentarily it will also disconnect from the grid. These time periods and voltages can be preset and are sometimes mandated by the DNO to safeguard the grid's power quality with respect to voltage. It could be quite a problem when a few/many solar PVs are grid connected on the same local distribution line.

The inverter cannot actually measure the grid voltage Vg - see my attached diagram - because it is connected to the grid by cables with resistance - Ri, Rs and Rd.. To export power the inverter voltage Vi must be greater than Vg. Thus when exporting power the inverter output voltage Vg depends on the grid voltage at the time Vg and the volt drop between the inverter and the grid which is I x (Ri + Rs + Rd).

At peak power output of 5kW the current I is circa 5000/250 = 20A.

The voltage drop is of the order Vd = 20 x (Ri + Rs + Rd). If the total resistance was say 0.2 Ohms then the volt drop while exporting 5kW at 20 A would be 20 x 0.2 = 4V. The installation may need the inverter cable (Ri) to be upgraded to reduce its effect on Vd and thence Vi. Not so easy to do this for Rs and Rd.

On a lightly loaded grid in summer the grid voltage Vg may well be high. On very sunny days with high levels of export Vi monitored by the inverter which is Vg +Vd may break one of the inverter voltage checks - rolling average or momentary excess. And it disconnects for a while.

There is also another 'feature' in the solis inverter which may be enabled. This is the power-voltage reduction profiler.

See Page 33 of the Manual of :

https://www.cclcomponents.com/solis-4g-5kw-solar-inverter-single-phase-2-mppt

where you can see the volt-watt diagram. See how the power reduces linearly when the voltage exceeds V3. V1, V2, V3 and V4 and the associated %power output may be preset. But I note the default settings are 100% for each of V1-4 so unless someone has set this feature up I do not think it is having any effect.

What to do?

1. Examine the size/csa and length of the cabling between the ac output of the inverter and the intake. Do a volt-drop calculation for I = 20-25 A. Is it 'excessive'? Could you tell us the length and csa in mm2?

2. Take some voltage measurements Vi, Vd(at intake) and Vg (disconnect installation from grid to do this). Do this on cloudy days, normal sunny days and peak sunny days. Do the voltages suggest the inverter is working as designed to disconnect if Vg is too high the rules for which I described earlier? Is their high voltage drop between intake and grid or inverter and intake? Ampclamp the ac output cable to measure I.

3. Check tightness of all connections.

4. If you have a three phase supply check that the inverter is connected to the phase with the highest loading.

5. Check to see that phase to phase voltages are about the same.

6. Check phase to Neutral voltages - this helps to discover a low conductance neutral.


I have to finish for now but I noted that two pieces of data the inverter monitors (and records?) are Vg and I - perhaps you could keep an eye on it?

Or something along these lines.

Errata - in my diagram voltmeter Vg should be at Tx - but you spotted that already.
[automerge]1598558210[/automerge]
whinmoor i believe its properly set see image below

PV Inverter cutting off array sunny days IMG_8030 - EletriciansForums.net




Have you or your installer checked the inverter is set to the correct country code? I've had inverters supplied which were pre-configured for another country which has led to this kind of problem. (Solis was not the manufacturer though).
 
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Sorry in advance everyone this is along thread with images.

Marconi,

I wanted to suppy some answers and images related to your post and see if I can figure this out see below in bold underlined.

Also I woud not be agianst havng someone login remotely and have a look at settings as this is possible on the Ginlong Solis webpage and via the app to interogate the inverter, I can supply password info on PM and pay for help if anyone thinks thay can identify this issue 100% so i can go back to the installer.


Maybe..... The absence of fault codes is because the inverter is fault free and operating as designed. As does the replacement.

On really sunny days there is peak PV generation for long period of say 5kW. Some or all of this power is exported to the grid. Let me assume for now it is all exported.

Each time it happens the battery is full.

PV Inverter cutting off array sunny days IMG_8033 - EletriciansForums.net


The Solis inverter computer monitors the grid voltage to detect its presence and to act if the voltage is too high or too low. If it acts it is to disconnect the inverter from the grid terminating the export of power.

So i assume if the battery was full and the house cannot take all the generated power from the roof it will discconnect from the Array as it in essence is no lonegr tied to the grid for excess power release?

The Solis inverter measures the grid voltage and if over a rolling say 5 minute period the average voltage is greater than say 255V it acts and disconnects the inverter from the grid. Also, if the grid voltage exceeds say 260V momentarily it will also disconnect from the grid. These time periods and voltages can be preset and are sometimes mandated by the DNO to safeguard the grid's power quality with respect to voltage. It could be quite a problem when a few/many solar PVs are grid connected on the same local distribution line.

We dont have DNO rules here in Ireland for PV system and we dont even have to advsie the network operator but the max array allowed is 6.3KW which is what i have. How do i check/change these presets in a solis inverter or is done at factory or as per the country code that is input? Wondering if using a country code from a country that has higehr voltage fluctuations above 260 could help


The inverter cannot actually measure the grid voltage Vg - see my attached diagram - because it is connected to the grid by cables with resistance - Ri, Rs and Rd.. To export power the inverter voltage Vi must be greater than Vg. Thus when exporting power the inverter output voltage Vg depends on the grid voltage at the time Vg and the volt drop between the inverter and the grid which is I x (Ri + Rs + Rd).

At peak power output of 5kW the current I is circa 5000/250 = 20A.

The voltage drop is of the order Vd = 20 x (Ri + Rs + Rd). If the total resistance was say 0.2 Ohms then the volt drop while exporting 5kW at 20 A would be 20 x 0.2 = 4V. The installation may need the inverter cable (Ri) to be upgraded to reduce its effect on Vd and thence Vi. Not so easy to do this for Rs and Rd.

On a lightly loaded grid in summer the grid voltage Vg may well be high. On very sunny days with high levels of export Vi monitored by the inverter which is Vg +Vd may break one of the inverter voltage checks - rolling average or momentary excess. And it disconnects for a while.

Is ther any way to see/measure VG and VD as form your diagram they seem to be other side of the intake which I assume is my meter cabinet?

There is also another 'feature' in the solis inverter which may be enabled. This is the power-voltage reduction profiler.

I had a look and cant tell if it is on or off see image. Is there any danger in turnng this off?

PV Inverter cutting off array sunny days IMG_8028 - EletriciansForums.net


See Page 33 of the Manual of :

https://www.cclcomponents.com/solis-4g-5kw-solar-inverter-single-phase-2-mppt

where you can see the volt-watt diagram. See how the power reduces linearly when the voltage exceeds V3. V1, V2, V3 and V4 and the associated %power output may be preset. But I note the default settings are 100% for each of V1-4 so unless someone has set this feature up I do not think it is having any effect.

What to do?

1. Examine the size/csa and length of the cabling between the ac output of the inverter and the intake. Do a volt-drop calculation for I = 20-25 A. Is it 'excessive'? Could you tell us the length and csa in mm2?
I will ask my installer but if it helps see atrached wiring diagram, test cert with cable gauges and image of AC cable well seated with 300/500V on sleeve etc

PV Inverter cutting off array sunny days IMG_8038 - EletriciansForums.net

PV Inverter cutting off array sunny days IMG_8037 - EletriciansForums.net

PV Inverter cutting off array sunny days IMG_8035 - EletriciansForums.net

2. Take some voltage measurements Vi, Vd(at intake) and Vg (disconnect installation from grid to do this). Do this on cloudy days, normal sunny days and peak sunny days. Do the voltages suggest the inverter is working as designed to disconnect if Vg is too high the rules for which I described earlier? Is their high voltage drop between intake and grid or inverter and intake? Ampclamp the ac output cable to measure I.

Thansk Im not in a position to do all of this due work etc but will ask installer

3. Check tightness of all connections.

Done everything is seated and tight

4. If you have a three phase supply check that the inverter is connected to the phase with the highest loading.

NA single phase only 11KW supply

5. Check to see that phase to phase voltages are about the same.

Not sure how to do this will ask installer

6. Check phase to Neutral voltages - this helps to discover a low conductance neutral.

Not sure how to do this will ask installer

Source URL: PV Inverter cutting off array sunny days - https://www.electriciansforums.net/threads/pv-inverter-cutting-off-array-sunny-days.189867/#post-1654050


I have to finish for now but I noted that two pieces of data the inverter monitors (and records?) are Vg and I - perhaps you could keep an eye on it?

I cant seem to see where this is monitired when i interrogate the inverter via the app i have the following avaialble Dc Volateg and Dc current PV1 and PV2, Total DC input power, AC volatge SVB, AC volatge TWC, AC Current RUA, AC Current SVB, AC Current TWC, Total Active power, AC output frequency, Grid Status, Grid Current RUA, Grid Voltage RUA, SOC/ SOH, and a few other which a just meters or battery related and likley not of any use.


Also does the below look correct, my app shows power flowing to the grid but I would have expected this backflow to have a setting in it.


PV Inverter cutting off array sunny days IMG_8027 - EletriciansForums.net


Or something along these lines.

Errata - in my diagram voltmeter Vg should be at Tx - but you spotted that already.
 
Thank you. Roughly how long is the 6mm cable run between the inverter and the consumer unit?
 
Cable is long as inverter is one side of property and consumer unit other it also has to go up and over into attic space and back down so approx 15m.

let me know if you would like access.

QUOTE="marconi, post: 1654139, member: 87486"]
I will study the inverter manual before deciding on whether to attempt remote access.

What else is in the plant room?
[/QUOTE]
[automerge]1598623935[/automerge]
there is a boiler in the room oil fired but not used during summer at all when the problem occurs also a nest controller and heating zone controller nothing that emits radiation and the boiler gives off little heat, the room is stable at 18-24 degrees all year round

I will study the inverter manual before deciding on whether to attempt remote access.

What else is in the plant room?
 
The screen image which shows 'Backflow Power' set to +0000W is odd because this it the limit set on exported PV power and it is/appears to be set to zero watts which might tie in with disconnection when the battery is 100% charged and if charging the battery is first use of PV energy ie: no battery charging and export at the same time.. Are you able to confirm from your generation meters that your installation has indeed exported power to the grid? On sunny days and low domestic load do you export? You could check this by turning off all the circuit breakers in the CU except for the one for the PV installation so any excess PV energy not being used to charge the battery is exported. Obviously best done when the battery is 100% charged if you can establish this. See 5.5.7.1 in manual.

Also, please confirm the state of the 'Off-Grid' mode see Fig 5.38.
 
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I spent ages chasing missed generation on my unit a long time ago was down to high DNO voltage in peek generation times, you may need to keep an eye on the supply, if i remember correctly no error was generated when mine stopped generating I could only see the problem in the PVoutput records

 
Uklad: That is a helpful post because it is a line of investigation at the moment - thank you Sir.
[automerge]1598627160[/automerge]

RonanIrl: I have used these plug in meters for untrained folk to check supply voltage. I need to check further but I think they report max and min values too ie: of power, frequency or voltage.

Anyway it would be a safe way for you to monitor the supply voltage and they are not too expensive. All you'd need to do is plug it in and select the mode for frequency and voltage.

RS PRO Wattmeter-energy meter for plug mounting | RS Components - https://uk.rs-online.com/web/p/digital-power-meters/1785370?cm_mmc=UK-PLA-DS3A-_-google-_-CSS_UK_EN_Automation_%26_Control_Gear_Whoop-_-Digital+Power+Meters_Whoop-_-1785370&matchtype=&pla-603078136763&gclid=Cj0KCQjw1qL6BRCmARIsADV9JtaSbVu2XipejALeE4RsCxyEs6atjfiyN41AqBpwCgSTW9rEtkJDX7gaAskbEALw_wcB&gclsrc=aw.ds
[automerge]1598627232[/automerge]
I spent ages chasing missed generation on my unit a long time ago was down to high DNO voltage in peek generation times, you may need to keep an eye on the supply, if i remember correctly no error was generated when mine stopped generating I could only see the problem in the PVoutput records


Uklad: What inverter type do you have please?
[automerge]1598628106[/automerge]
Cable is long as inverter is one side of property and consumer unit other it also has to go up and over into attic space and back down so approx 15m.

What is the length of cable in the attic space please?

How hot does it get in the attic space on the problem sunny days?
[automerge]1598628649[/automerge]
Please look carefully at the white cable to the inverter which wends its way to the CU via the loft. Imprinted on it should be a figure in mm2 - what is it?

And what is the BS number?
 
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Thanks Marconi and UKLad I will order one Of the monitors and set it up.

Im on a few days holidays as of this morning so away from home but will be back with more info next weekend

will be back with BS standard of the cable I just missed it in the images I sent can only see BS EN but number is missing.

I have a solis 5kw hybrid inverter

The attic doesn’t get over 27 in summer and approx 12m of the 15m cable run through it.



Uklad: That is a helpful post because it is a line of investigation at the moment - thank you Sir.
[automerge]1598627160[/automerge]

RonanIrl: I have used these plug in meters for untrained folk to check supply voltage. I need to check further but I think they report max and min values too ie: of power, frequency or voltage.

Anyway it would be a safe way for you to monitor the supply voltage and they are not too expensive. All you'd need to do is plug it in and select the mode for frequency and voltage.

RS PRO Wattmeter-energy meter for plug mounting | RS Components - https://uk.rs-online.com/web/p/digital-power-meters/1785370?cm_mmc=UK-PLA-DS3A-_-google-_-CSS_UK_EN_Automation_%26_Control_Gear_Whoop-_-Digital+Power+Meters_Whoop-_-1785370&matchtype=&pla-603078136763&gclid=Cj0KCQjw1qL6BRCmARIsADV9JtaSbVu2XipejALeE4RsCxyEs6atjfiyN41AqBpwCgSTW9rEtkJDX7gaAskbEALw_wcB&gclsrc=aw.ds
[automerge]1598627232[/automerge]


Uklad: What inverter type do you have please?
[automerge]1598628106[/automerge]
Cable is long as inverter is one side of property and consumer unit other it also has to go up and over into attic space and back down so approx 15m.

.



What is the length of cable in the attic space please?

How hot does it get in the attic space on the problem sunny days?
[automerge]1598628649[/automerge]
Please look carefully at the white cable to the inverter which wends its way to the CU via the loft. Imprinted on it should be a figure in mm2 - what is it?

And what is the BS number?
 

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