4000TL: no output

[digital48]

I noticed yesterday that my SMA 4000TL spent 30 or so minutes producing 0 Watts. There are two arrays on the system and when I checked the inverter display it was showing one of them at 305V between the panels and the inverter and 245V between inverter and the grid. The red light was also on on the inverter.

Checking the error log, there are a few events over time of the type:

EventCode EventType Category Group Tag 1 Incoming Warning Grid Monitoring Grid fault 1 Incoming Error Grid Monitoring Grid fault 1 Outgoing Info Grid Monitoring Grid fault

This is a 3.99kWP set to G59/2 (the inverter shows ADJ when it's woken up) with DNO consent.

Can anyone explain what's happening and what might need to be done please? As you may have guessed, I'm a consumer and not an installer!

TIA

Edit: Apologies but the formatting I applied to the error report won't stick

 

[SolarCity]

Did the DNO ask that inverter be set up for G59 as a condition of installing? I've known them ask for alterations to frequency tolerances before but not for full-monty G59.

It could be that you have a high grid voltage as this seems to be the most common problem.

 

[digital48]

Did the DNO ask that inverter be set up for G59 as a condition of installing? I've known them ask for alterations to frequency tolerances before but not for full-monty G59.

I don't know that they asked for it, but they have agreed to it (I have a letter stating so) and, as far as I can tell, that's how the inverter is set up.

It could be that you have a high grid voltage as this seems to be the most common problem.

Is this something that can be 'fixed' on the inverter, or something I'll have to live with? It seems a pity to lose half an hour's generation on a bright sunny day!

 

[whinmoor]

What brand of panels do you have? There have apparently been compatibility issues between certain brands and SMA 4000TLs.

 

[SibertSolar]

Isn't the upper voltage limit lower for G59 than it is for G83?......would that exacerbate a high grid voltage "problem"?

 

[MorganPVI]

253v is the G59 voltage.

 

[digital48]

What brand of panels do you have? There have apparently been compatibility issues between certain brands and SMA 4000TLs.

Canadian Solar 190.

 

[Glen Powell]

This problem has stated raising its head from systems we supplied but not installed, I have a feeling it is down to wire sizing with the greater current going through the voltage increases (only a theory) this could then in turn give a grid fault.

The only reason I say this is when I ask what wire size has been used and over what distance I have not had a clear answer, it revolves around I will check the paperwork and get back to you.

 

[Gary K]

I don't know that they asked for it, but they have agreed to it (I have a letter stating so) and, as far as I can tell, that's how the inverter is set up.



Is this something that can be 'fixed' on the inverter, or something I'll have to live with? It seems a pity to lose half an hour's generation on a bright sunny day!

You could try turning everything off and back on at the isolator when you notice it happening- it seem to sort it temperarily for some people.

 

[Gavin A]

What brand of panels do you have? There have apparently been compatibility issues between certain brands and SMA 4000TLs.

it's not this, as the output is zero and it's showing a grid fault.

what size cable has been used, and what length of cable from inverter to mains?

chances are that it's an overvoltage issue with the mains. The inverter is supposed to cut out when the grid voltage goes above certain levels, and if it happens once in a blue moon it's not an issue. If it's happening more often than this, then you need to be having discussions with your dno about getting them to monitor it and hopefully adjust the tapping on the transformer.

If the cable from the inverter is too small / too long a cable run, then this can exacerbate the problem as the inverter has to effectively push the power out harder (aka at a higher voltage) to get it all through the cable, so worth double checking this first.

Also check the grid voltage reading on the inverter before the inverter starts feeding in, and immediately afterwards a few times at peak generation to see what difference the inverter makes to the voltage it's seeing.

 

[digital48]

what size cable has been used, and what length of cable from inverter to mains?

Looks like the thinnest is 2.5mm twin and earth from the generation meter to the isolator (there's much thicker in a white sheath from inverter to the meter) and the total length is around a metre.

Also check the grid voltage reading on the inverter before the inverter starts feeding in, and immediately afterwards a few times at peak generation to see what difference the inverter makes to the voltage it's seeing.

I'll try to catch it!

It does seem to trip after it's been pushing out at its maximum for the day (2.7kW?) for a while.