Solar Inverter Issues

[Horn&corn]

Our 28kw roof System is showing drop on output on a couple of strings sometimes. Showing full power when it’s dull but at mid day a couple drop down to About half Output. Any ideas or recommendations on someone to look at it?
Abb Trio inverter
north Wiltshire

 

[Chickcatcher]

I am also having issues 3 inverters work and then dont work "SMA" investigating further thanks to a "Smart" meter we have seen today voltages on the 3 phases varying over 30% L1 270, L2 260 and L3 200, volts Ukpower network on there way. perhaps a bit far for you but there is BeBa based at Hemel Hempstead.

 

[Exfarmer]

You certainly need some string testing done. I would be worried about the MC4 connectors.
Other issues have you checked the max voltage experienced tp by the system on the gris side.
We have had huge problems on one site where the grid voltage on one phase went up to over 300 volts.
I believe this was due to a nearby large PV which was on only on single phase. I have no idea how they got permission to build it.

 

[Deereone]

This problem occurs when another PV system supplying the same transformer is set up to push slightly more into the grid than your system leaving your system to cut out until their exported voltage drops enough to allow yours to fire up again. I blame the buyers for allowing more suppliers to 'feed in' than the system can take.

 

[Chickcatcher]

All sorted by UK Power neutral attachment close to the transformer was hardly hanging together by a thread. the connection described by the engineer as pretty poor. It had been there for around 30 years.

 

[Exfarmer]

All sorted by UK Power neutral attachment close to the transformer was hardly hanging together by a thread. the connection described by the engineer as pretty poor. It had been there for around 30 years.

Common issue little routine maintenance, just fire brigade work

 

[nonemouse]

What is minimum grid voltage the the power network has to supply? We have a 20kw solar system on single phase that’s been working for the last 9 years. The last couple of weeks we’ve been having problems of our inverters not powering up (say waiting for grid voltage) our supply voltage seems very erratic, lowest I’ve seen this morning is 218volts.

 

[Deereone]

216.2- 253v

 

[Exfarmer]

What is minimum grid voltage the the power network has to supply? We have a 20kw solar system on single phase that’s been working for the last 9 years. The last couple of weeks we’ve been having problems of our inverters not powering up (say waiting for grid voltage) our supply voltage seems very erratic, lowest I’ve seen this morning is 218volts.

I would guess they have had issues elsewhere with over voltage on that phase, so they have turned the taps down. I expect your inverter is calibrated too high .
Probably worth speaking to Local Network operator about the low voltage, but it is with in the allowable parameters

 

[nonemouse]

216.2- 253v

Thanks, so no doubt they will claim grid supply is fine, inverters seem to get up set when supply drops below 225v

 

[Exfarmer]

Thanks, so no doubt they will claim grid supply is fine, inverters seem to get up set when supply drops below 225v

What make and model are the inverters?

 

[nonemouse]

What make and model are the inverters?

5kw SMA inverters not sure on a model no without looking

 

[Exfarmer]

5kw SMA inverters not sure on a model no without looking

It may be possible to change the settings without too much trouble. I am not familiar with SMA but many you can alter the country in the set up. It may be the country is set to voltages which are different parameters to ours. Sadly I cannot help