Advice Please

[Buckfast]

Called to a property today to carry out repairs etc. When completed customer asked me could i have a quick look at photovoltaic system. Received only one cheque in 2 1/2 years for generation. Invertor was not generating.
Invertor is an Eversol TL 1500 giving a fault of, 'Output Relay Fault'. The system has 8 panels mounted on garage roof and these are connected as two strings of four which are then connected in Parrallel at the DC isolation switch with only one +ve -Ve going to invertor. String one gave me 204 Volts and String two gave 196 Volts DC. The input supply to AC isolator ok at 240V. Tried rersetting invertor with same fault appearing. I would say invertor fault ?. But if invertor replaced could i not connect all panels in series ? as long as this was less than the max input DC voltage. Is there a reason why they would be wired in parrallel.

 

[Gavin A]

agreed, looks like inverter fault. can't see why not to connect in series as long as voltage is ok.... wired in parrallel erm installer whim?

 

[Buckfast]

Would an ABB UNO-2.0-TL-OUTD be a good quality replacement. I would prefer to use a more expensive inverter but better quality rather than a cheap and cheerful ?. Assuming each panel 250W ? would i be better going to a 2.5kW Inverter.

 

[Worcester]

Would an ABB UNO-2.0-TL-OUTD be a good quality replacement.

Maybe, we've replaced so many 3.6's with the 031 error (output relay!) this year, and with an average 7 week turnaround for a replacement from Italy, we now only install SMA.

I would prefer to use a more expensive inverter but better quality rather than a cheap and cheerful

Agree

 

[whinmoor]

The original inverter probably had a 5 year manufacturer's warranty. It's certainly worth investigating whether you can get a replacement.

To answer the question, yes, an ABB unit is a high-quality option.

The voltages seem rather high for just 4 panels. Can you confirm the brand and power of the panels?

 

[Buckfast]

The original inverter probably had a 5 year manufacturer's warranty. It's certainly worth investigating whether you can get a replacement.

To answer the question, yes, an ABB unit is a high-quality option.

The voltages seem rather high for just 4 panels. Can you confirm the brand and power of the panels?

Whinmoor, i went past job tonight whilst out walking dog and you are correct regarding voltages for panels. I really must learn to count, there are infact 10 panels (2*5 panel strings which are connected in parrallel). I have not looked at panels but assumed as installation 4 to 5 years of age that the panel would be no bigger than 250W each. This now leads me to think the reason original inverter failed is it has been driven to hard. 1.5kW invertor dealing with a possible 2.5kW. Would a 2.5kW invertor still be ok or would a 3kW be better being driven at 70 to 80% in summer months.

 

[whinmoor]

It will say on the MCS certificate what brand has been used and you should be able to work out the power class. There should be some paperwork somewhere. If it's under 5 years, I'd be looking to get a replacement under warranty ASAP. (Of course, you don't have to fit the replacement - you could keep it as a spare or sell it on ebay.).

You may get a Zeversolar as the replacement. This company is now owned by SMA.

 

[Buckfast]

It will say on the MCS certificate what brand has been used and you should be able to work out the power class. There should be some paperwork somewhere. If it's under 5 years, I'd be looking to get a replacement under warranty ASAP. (Of course, you don't have to fit the replacement - you could keep it as a spare or sell it on ebay.).

You may get a Zeversolar as the replacement. This company is now owned by SMA.

The problem with this is the customer i have never worked for before. They are a little dizzy to say the least, hence only one cheque for FIT since buying house over 3 years ago. They have no information whatsoever and the original owners of property now deceased. Without getting too involved removing panels etc the only information i have is number of panels (Got that wrong ?) and original invertor specification plate. Installation poor. Connected on 20A 60898B Mcb to load side of 30mA rcd supplying other circuits !. 2.5mm T&E in loft through insulation, invertor which appears under sized. Was hoping to just replace inverter, check with new inverter manufactures regarding rcd neccesity and if required moving circuit to its own rcd protected circuit to prevent the rcd second fault scenario. Also decrease mcb size and increase ac cable to 4.0mm.

 

[SolarRoofSols]

The problem with this is the customer i have never worked for before. They are a little dizzy to say the least, hence only one cheque for FIT since buying house over 3 years ago. They have no information whatsoever and the original owners of property now deceased. Without getting too involved removing panels etc the only information i have is number of panels (Got that wrong ?) and original invertor specification plate. Installation poor. Connected on 20A 60898B Mcb to load side of 30mA rcd supplying other circuits !. 2.5mm T&E in loft through insulation, invertor which appears under sized. Was hoping to just replace inverter, check with new inverter manufactures regarding rcd neccesity and if required moving circuit to its own rcd protected circuit to prevent the rcd second fault scenario. Also decrease mcb size and increase ac cable to 4.0mm.

If you contact MCS they should be able to get you a copy of the Certificate which will have the panel details on, OR the company they got the 1 FIT payment from, they may be able to access the information.

 

[gnselectricals]

Generally in my experience inverter is slightly undersized so runs flat out under the majority of conditions through the year as max generation from panels won't be seen through the year.

 

[whinmoor]

Can you measure the dimensions of the panels? If they are only about 80cm across, you probably have 190 - 210w panels. If they are around 100cm across, you've probably got 230-250w panels. (Unless, of course they are Sanyos).

If you can post photos on here, we may be able to help better.

 

[Buckfast]

Can you measure the dimensions of the panels? If they are only about 80cm across, you probably have 190 - 210w panels. If they are around 100cm across, you've probably got 230-250w panels. (Unless, of course they are Sanyos).

If you can post photos on here, we may be able to help better.

Thanks for all the input from everyone. I am going back to the property again next week to carry out more repairs. I will try to get as much information from customer etc then.

 

[Buckfast]

Just to update. Customer unable to get information regarding installation from MCS ?. He says he has had a lot of trouble with BG who say that although he owns property that he has to prove that he owns panels installed by previous owner. Has said that he just cannot be bothered with the whole thing and has asked me to remove all panels and metering equipment from property in new year.

 

[SolarRoofSols]

Just to update. Customer unable to get information regarding installation from MCS ?. He says he has had a lot of trouble with BG who say that although he owns property that he has to prove that he owns panels installed by previous owner. Has said that he just cannot be bothered with the whole thing and has asked me to remove all panels and metering equipment from property in new year.

When the house was sold - a handover form should have been signed by the previous owner - it should have been sorted out by his solicitor really - he may be able to take them to task on it? He'd be better off keeping them and looking into battery storage when the prices come down.