Inverters dropping out?

[matthew]

Just this spring, after months of grey weather, we have sun. Lots of it. But our inverters have occasionally been dropping out of supplying the grid. First the 30 kw one and today the 20kw.
Is this because the grid is to capacity? (And old)

I haven’t asked our installers or export purchasers yet, but wondered if the TFF collective may know.
Thks.

 

[200tdi]

Check the grid voltage, the inverter settings, and fault history
Anything over 253 per phase will cause a fault to register and a restart

 

[matthew]

Check the grid voltage, the inverter settings, and fault history
Anything over 253 per phase will cause a fault to register and a restart

That seems to be what’s happening. Will check later.
The fault isn’t constant, nor is it confined too one inverter. Intermittent. The worst sort.

 

[Bury the Trash]

That seems to be what’s happening. Will check later.
The fault isn’t constant, nor is it confined too one inverter. Intermittent. The worst sort.

do they have a cooling system / fans if so are they working effectively if they havnt been on for awhile.

 

[f0ster]

you might not get a fault on the inverter if it is high grid voltage, the fault is not with the inverter and so they just do a restart and check the incoming voltage before locking on to the grid again,
some inverters have a calibration facility so that you can adjust what voltage the inverter is seeing in case it is reading the incoming voltage incorrectly, plus or minus 5v.

 

[matthew]

do they have a cooling system / fans if so are they working effectively if they havnt been on for awhile.

No idea. Beyond my paygrade!
Will ask tomorrow.

you might not get a fault on the inverter if it is high grid voltage, the fault is not with the inverter and so they just do a restart and check the incoming voltage before locking on to the grid again,
some inverters have a calibration facility so that you can adjust what voltage the inverter is seeing in case it is reading the incoming voltage incorrectly, plus or minus 5v.

That seems to be what is happening. One inverter is fine (today) but the other trying to connect, then cutting off.
I will enquire of the installers- who are local fortunately, tomorrow.

 

[Exfarmer]

What make of inverters ?
as others say this is most likely over voltage with high sunshine at mid day.
with the rise of solar farms the system is getting over loaded at lunchtime .
it is quite likely your inverters will show grid voltage if you quiz them. I have seen 305 volts on one phase when neighbour installed a 30 kw system on his single phase property, do not know how he was given permission , think some one at DNO cocked up.
if you suspect over voltage DNO should install a monitor which will quickly detect problems

 

[matthew]

What make of inverters ?
as others say this is most likely over voltage with high sunshine at mid day.
with the rise of solar farms the system is getting over loaded at lunchtime .
it is quite likely your inverters will show grid voltage if you quiz them. I have seen 305 volts on one phase when neighbour installed a 30 kw system on his single phase property, do not know how he was given permission , think some one at DNO cocked up.
if you suspect over voltage DNO should install a monitor which will quickly detect problems

One original Aurora and a replacement ( under warranty) ABB.
Western Power is the DNO.

 

[Exfarmer]

I‘m sorry have no knowledge of either as to how to quiz them.
if you just play with the buttons you will do no harm and may gain some knowledge of what is happening

 

[matthew]

I‘m sorry have no knowledge of either as to how to quiz them.
if you just play with the buttons you will do no harm and may gain some knowledge of what is happening

WPD / National Grid - or whatever they're calling themselves today - will not look or check their voltage until an installer has checked the installation.
So, fortunately the installer is still in business - many are not - and is calling in wednesday.

If it isn't an inverter fault, then only they (installers) can contact the National Grid for a resolution. Not the owner of said installation who paid the Grid for a connection at an agreed capacity of exported power.

So we'll have to wait and see...

 

[Exfarmer]

WPD / National Grid - or whatever they're calling themselves today - will not look or check their voltage until an installer has checked the installation.
So, fortunately the installer is still in business - many are not - and is calling in wednesday.

If it isn't an inverter fault, then only they (installers) can contact the National Grid for a resolution. Not the owner of said installation who paid the Grid for a connection at an agreed capacity of exported power.

So we'll have to wait and see...

luckily when we had issues our DNO was happy to speak to me as the owner of the array. They did at the time suggest as did the guy who came out that it was he inverters reading faulty rather their voltage issues. When the chap looked first time he did not believe the voltage could have gone up as high as we said. but put monitoring equipment on. Came out a week later and saw the figures and nearly had a heart attack! He said it was the highest figure ( 305 volts on one phase) he had ever seen
I do seem to remember when we originally complained there was mention of a call out fee if we were wrong though.
My newer inverters will cut out instantly if there is voltage over 253 but have not had any real issues as they quickly reset

 

[sjt01]

luckily when we had issues our DNO was happy to speak to me as the owner of the array. They did at the time suggest as did the guy who came out that it was he inverters reading faulty rather their voltage issues. When the chap looked first time he did not believe the voltage could have gone up as high as we said. but put monitoring equipment on. Came out a week later and saw the figures and nearly had a heart attack! He said it was the highest figure ( 305 volts on one phase) he had ever seen
I do seem to remember when we originally complained there was mention of a call out fee if we were wrong though.
My newer inverters will cut out instantly if there is voltage over 253 but have not had any real issues as they quickly reset

Do the inverters not maintain a downloadable log? Our CHP control system provides this log:
02-11-2023;04:54:24;546;;mains protection: delta undervoltage 1;30671;3;
02-11-2023;04:54:24;546;;mains protection: star undervoltage 1;30672;3;
02-11-2023;04:54:25;741;;mains protection: release delay for synchronizing;30662;3;
02-11-2023;04:54:33;736;Q;mains protection: release delay for synchronizing;30662;3;
02-11-2023;04:54:34;705;Q;mains protection: delta undervoltage 1;30671;3;
02-11-2023;04:54:34;705;Q;mains protection: star undervoltage 1;30672;3;
02-11-2023;04:55:26;806;;df/dt;30677;3;
02-11-2023;04:55:26;825;;mains protection: delta undervoltage 1;30671;3;
02-11-2023;04:55:26;825;;mains protection: star undervoltage 1;30672;3;
02-11-2023;04:55:28;738;;mains protection: release delay for synchronizing;30662;3;
02-11-2023;04:55:36;865;Q;df/dt;30677;3;
02-11-2023;04:55:38;739;Q;mains protection: release delay for synchronizing;30662;3;
02-11-2023;04:55:39;046;Q;mains protection: delta undervoltage 1;30671;3;
02-11-2023;04:55:39;046;Q;mains protection: star undervoltage 1;30672;3;
02-11-2023;04:55:49;046;;mains protection: delta undervoltage 1;30671;3;
02-11-2023;04:55:49;046;;mains protection: star undervoltage 1;30672;3;
02-11-2023;04:55:59;566;Q;mains protection: delta undervoltage 1;30671;3;
02-11-2023;04:55:59;566;Q;mains protection: star undervoltage 1;30672;3;

I guess the G99 function is built into the inverter, we have a separate G59 relay which also maintains an event log.

 

[matthew]

Possibly they do.
OH may be able to press buttons.
Me? I know nuffink.

 

[Exfarmer]

Do the inverters not maintain a downloadable log? Our CHP control system provides this log:
02-11-2023;04:54:24;546;;mains protection: delta undervoltage 1;30671;3;
02-11-2023;04:54:24;546;;mains protection: star undervoltage 1;30672;3;
02-11-2023;04:54:25;741;;mains protection: release delay for synchronizing;30662;3;
02-11-2023;04:54:33;736;Q;mains protection: release delay for synchronizing;30662;3;
02-11-2023;04:54:34;705;Q;mains protection: delta undervoltage 1;30671;3;
02-11-2023;04:54:34;705;Q;mains protection: star undervoltage 1;30672;3;
02-11-2023;04:55:26;806;;df/dt;30677;3;
02-11-2023;04:55:26;825;;mains protection: delta undervoltage 1;30671;3;
02-11-2023;04:55:26;825;;mains protection: star undervoltage 1;30672;3;
02-11-2023;04:55:28;738;;mains protection: release delay for synchronizing;30662;3;
02-11-2023;04:55:36;865;Q;df/dt;30677;3;
02-11-2023;04:55:38;739;Q;mains protection: release delay for synchronizing;30662;3;
02-11-2023;04:55:39;046;Q;mains protection: delta undervoltage 1;30671;3;
02-11-2023;04:55:39;046;Q;mains protection: star undervoltage 1;30672;3;
02-11-2023;04:55:49;046;;mains protection: delta undervoltage 1;30671;3;
02-11-2023;04:55:49;046;;mains protection: star undervoltage 1;30672;3;
02-11-2023;04:55:59;566;Q;mains protection: delta undervoltage 1;30671;3;
02-11-2023;04:55:59;566;Q;mains protection: star undervoltage 1;30672;3;

I guess the G99 function is built into the inverter, we have a separate G59 relay which also maintains an event log.

I think most inverters maintain logs. Accessibility from the buttons is not always that easy and notmally require access via a laptop to gain the full info. Older inverters may need an ethernet connection and some historic programme

 

[matthew]

Our installer came on wednesday, and as suggested, pressed several buttons.
Two of the three phases were not linking to the grid. So he says, the grid is OK and the inverter is fine, but the MCB (?) may be tired.
At the moment, touching wood, all seems fine. But if it misbehaves again, a new MCB (?) will be fitted.

Thanks for all your replies.

 

[Exfarmer]

Our installer came on wednesday, and as suggested, pressed several buttons.
Two of the three phases were not linking to the grid. So he says, the grid is OK and the inverter is fine, but the MCB (?) may be tired.
At the moment, touching wood, all seems fine. But if it misbehaves again, a new MCB (?) will be fitted.

Thanks for all your replies.

If the MCB is tired change it quick they should not expensive