Why I get a voltage drop from my solar panels on the early morning and late evening

[BruceB]

Re: Why I get a voltage drop from my solar panels on the early morning and late eveni

BruceB
I don't think that will sort the problem. I don't know what the start up voltage is on this inverter but the specs I have certainly sugest you will struggle to achieve even operating voltage from this array. Thats why the inverter has been derated and why there is a problem.

It's the wrong inverter, period

You might be right. I have not installed Fronius and based my answer on other (SMA & Power One) inverters. Having now had a look at the Fronius manual it appears that the startup voltage is 150V and is not alterable by the user or installer based on the settings available in the published manual. It is possible Fronius service partners who have done the course have access to more detailed settings. I'll leave that for others to pick up and bow out.

 

[moggy1968]

Re: Why I get a voltage drop from my solar panels on the early morning and late eveni

OK, thats good info Bruce. At 150V start up voltage it shouldn't have needed changing by the installer then. mY data sheet for the Fronius IG gives an operating voltage of 350-700V, which is much too much for this system.

Either way, it's the wrong inverter though. I would suggest a change to a smaller inverter will solve the problem but really the system needs checking out by a decent installer.

 

[cham cham]

Re: Why I get a voltage drop from my solar panels on the early morning and late eveni

OK, thats good info Bruce. At 150V start up voltage it shouldn't have needed changing by the installer then. mY data sheet for the Fronius IG gives an operating voltage of 350-700V, which is much too much for this system.

Either way, it's the wrong inverter though. I would suggest a change to a smaller inverter will solve the problem but really the system needs checking out by a decent installer.

I look at the manual on this inverter. The start-up voltage is 150v to 400v I check on the inverter total. It shows on the screen. The total maximum voltage comes from the array is 304 volts. The minimum recoded 271 volts. So it well above the start-up voltage of 150v
In the morning the voltage come to the point if 150v. The inverter is waked up. At the point of connection at 150v the voltage drop back to below 100v turn the inverter off. then in few second the voltage increase back again to the point of 150v it start the inverter again at that point the voltage drop again below 100v cause the inverter to turn off.
When it’s become brighter than the inverter is not dropping the voltage below 100v and stay connected until connect to the grid. At the last few minutes before connect to the grid. a message appear on the screen. Low DC power or DC power low. After a few second of that message then it connects to the grid.
The only problem I got is at early morning. And late afternoon. The voltage drop from 150 to below 100.
I think the inverter is wake up half an hour early it supposed to in the morning. And stay connected on for half an hour longer than supposed to. I don’t know if something wrong with panel for dropping the voltage or if something wrong with inverter.
When I turn on the inverter manually in the morning half an hour later then it supposed to wake up. It connects straight to the grid none of this problem of on and off.
I don’t want to change something that end up something else is wrong. I mean if the system is under power If add a few more panel to the system do you think it will fix this problem.

 

[whinmoor]

Re: Why I get a voltage drop from my solar panels on the early morning and late eveni

Do you have space on your roof for more panels? I wonder why the previous owner didn't max out?

I think you need to identify the original installer (if they are still trading) and politely request a site visit to discuss the issues. They should have registered the installation with Building Control at your local council. You should also have an official MCS certificate which gives their name. Surely you got some paperwork about the PV system when you bought the property? If not, it might be worth discussing with your solicitor/conveyancer.

If you tell us where in the UK you are located, someone from this forum might be able to offer assistance.

 

[Earthstore]

Re: Why I get a voltage drop from my solar panels on the early morning and late eveni

Your FIT provider should have a copy of your MCS certificate, the installer should be on there, of course it depends on how helpful your FIT provider is....

 

[moggy1968]

Re: Why I get a voltage drop from my solar panels on the early morning and late eveni

as above!! You need some one to visit you.

looks like I am barking up the wrong tree then with start up voltages

 

[stodsy]

Re: Why I get a voltage drop from my solar panels on the early morning and late eveni

do you live in a rural place if so the transformer in your area might need tweeking get in touch with the dno you can buy a vphase transformer for your house this will help as well

 

[Earthstore]

Re: Why I get a voltage drop from my solar panels on the early morning and late eveni

do you live in a rural place if so the transformer in your area might need tweeking get in touch with the dno you can buy a vphase transformer for your house this will help as well

It will not help with the PV, the PV has to be connected in before the voltage optimiser.

 

[cham cham]

Re: Why I get a voltage drop from my solar panels on the early morning and late eveni

Do you have space on your roof for more panels? I wonder why the previous owner didn't max out?

I think you need to identify the original installer (if they are still trading) and politely request a site visit to discuss the issues. They should have registered the installation with Building Control at your local council. You should also have an official MCS certificate which gives their name. Surely you got some paperwork about the PV system when you bought the property? If not, it might be worth discussing with your solicitor/conveyancer.

If you tell us where in the UK you are located, someone from this forum might be able to offer assistance.

Thank you for your reply
At the moment I can’t afford to replace the inverter or add more panels I just move in as you know of so many expenses to word the house but I did contact the solicitor he said he is going to come back to me when he hear from the previous owner. I don’t have any contact detail of the installer with house paper. I hope he did not install it himself. I did not new that I should have the paper work for the solar panel installation.
For the time been I just turn it on the DC half an hours later in the morning than it should start and I turn it off the DC half an hour early than it should stop in the evening With no problem. If there is any other better solution than this I love to hear it. I may turn it off all together until I got fund to get an electrician to repair it or upgrade.
I don’t think it anything wrong with the inverter because it works absolutely perfect during the day. Not even turn off once. I think this inverter is over power if I add more panels I think this problem may disappear. When I check in the Fronius Configuration Tool. I should have connected 11 panels 245 watts instead of 8 panels at the moment. what will be the maximum cost to fix this problem? I mean just the labour cost. So I can call someone at the right time and not been charge too much for the this job Thank you

 

[moggy1968]

Re: Why I get a voltage drop from my solar panels on the early morning and late eveni

It's not as simple as just adding some panels, your system has been registered (possibly!) as is and any new panels have to be registered separately. This isn't a DIY job. you need a qualified, and reputable, installer to advise you, which most that fit that description will be prepared to do with no commitment and may be able to advise you on your current install. As I said sometime ago, you need someone to see this in real life.