Really Need Some advise Urgently

[Earthstore]

That looks quite neat, well apart from the board that is, it should really have two AC isolators though, one for each inverter.

The tripping/high voltage that has been referred to is the AC voltage, if it is quite high coming into the house IE around 250v, and the AC cable to the inverters is too small it can cause the inverter to go over voltage, it is a very common install fault.

I hope this helps.

 

[crazygraham]

There is only the one ac isolator installed should there be a second one at the other side of the meter ?
I had asked for the gen meter to be in the electric box but was told it had to go up above.

 

[whinmoor]

At first glance it looks neat, tidy and symmetrical.

Two things jump out at me. Firstly, the lack of a fireproof board. We always use one when installing on wood. We tend to use plywood rather than chipboard.

Secondly, the DC isolators don’t look very far from the inverter. According to the installation instructions, there should be 300mm ventilation clearance above the inverter. Page 16 of this: View attachment SB30TL_40TL_50TL-IA-IEN120231.pdf.

You can see some of our installations as case studies on our website. We don’t normally attempt to conceal the cables when they are in a loft.

 

[crazygraham]

That looks quite neat, well apart from the board that is, it should really have two AC isolators though, one for each inverter.

The tripping/high voltage that has been referred to is the AC voltage, if it is quite high coming into the house IE around 250v, and the AC cable to the inverters is too small it can cause the inverter to go over voltage, it is a very common install fault.

I hope this helps.

Should there be one for each inverter then should I ask for another ?

They have used a 6mm cable from the loft to the consumer unit is that cable size ok?
And a 4mm cables for the dc array side.

 

[Earthstore]

The generation meter is normally mounted where you can read it easily, IE downstairs.
There can be a tiny advantage in having it close to the inverter though, and that is it does not suffer from any voltage losses in the cable, but most installers would install it where you can see it easily.

 

[Earthstore]

At a guess, and it depends on the cable length, 6mm should be OK, but without all the full spec you can not calculate it.

 

[MorganPVI]

SMA installation manual clearly states:

- Inverters to be mounted on heatproof surface, if not a brick wall then a fire proof board
- Each inverter must be on a separate MCB - therefore with this config you;d want 2 AC isolators
- RCD should be 100ma - if RCD is required

To be fair I was expecting a real dogs dinner, much neater than I'd have thought based on the OP's description. Cable sizing seems to be correct, better than the 1.5mm cable some muppet was running a 4000tl on in a previously posted horror story.

 

[BruceB]

I would agree pretty much with what has been said so far but with a couple of tweaks:

- Each inverter must be on its own mcb to meet the manufacturers instructions as already stated. A separate ac isolator for each (big red rotary knob), whilst useful is not essential and you could have one covering both inverters as they have done, because the inverters are right beside each other.

- If you have an rcd then it should be 200mA to meet the manufacturers instructions. Quote below is from the SMA rcd selection manual:
"For every connected inverter, a rated residual current of 100 mA has to be planned. The RCD's rated residual
current must at least correspond to the sum of the rated residual currents of the connected inverters. That means
that, if, for example, 3 transformerless inverters are connected, the rated residual current of the RCD has to be
a minimum of 300 mA."

As others have said, at first glance it is neat, which is a good sign.

 

[finchy]

As above .......

plus and the meter looks like its missing a Seal !

The installer must have missed the MCS Metering guidance

"5. Sealing

The meter and terminal cover should be sealed to ensure that the customer cannot​

access either.
"

 

[SPARTYKUS]

I would agree pretty much with what has been said so far but with a couple of tweaks:

- Each inverter must be on its own mcb to meet the manufacturers instructions as already stated. A separate ac isolator for each (big red rotary knob), whilst useful is not essential and you could have one covering both inverters as they have done, because the inverters are right beside each other.

- If you have an rcd then it should be 200mA to meet the manufacturers instructions. Quote below is from the SMA rcd selection manual:
"For every connected inverter, a rated residual current of 100 mA has to be planned. The RCD's rated residual
current must at least correspond to the sum of the rated residual currents of the connected inverters. That means
that, if, for example, 3 transformerless inverters are connected, the rated residual current of the RCD has to be
a minimum of 300 mA."

As others have said, at first glance it is neat, which is a good sign.

Neatness takes time, time is money. As said always a good sign in my opinion. also shows perhaps a little pride in their work.

 

[moggy1968]

I've never done a 2 inverter install, but am interested as to why 2 MCBs. That would require 2 meters. When we have discussed this before it was suggested to run the inverters in parallel at the isolator, then to the meter and on to a single MCB.

Looks a neat job, which, as above bodes well. there should be a second AC isolator at the DB, where you would usually also have the meter. I am guessing there is a space issue there.

6 mm cable is almost certainly fine.
The number od DC isolators suggests each array is split into 2 strings. I don't understand why they would do that. I would have thought each array to a single string to the inverter..

personally I would have gone for a single 2 MPPT inverter but thats just a matter of choice.

 

[sedgy34]

I suppose the 2nd ac isolator is there somewhere???? DC isolators could be classed as being a little close to the top of the inverters and so may cause a little bit of airflow restriction, doubt if it would be that bad on an east/west roof though. Gen meter by inverters has never really been our preferred location, especially if the client is elderly and can't climb into the loft every quarter to read the thing!

i agree with the 2nd ac isolator but everything else (behave)

 

[SolarCity]

I've never done a 2 inverter install, but am interested as to why 2 MCBs. That would require 2 meters. When we have discussed this before it was suggested to run the inverters in parallel at the isolator, then to the meter and on to a single MCB.

Not if you connect the meter before a consumer unit supplying the inverters only.

 

[crazygraham]

I've never done a 2 inverter install, but am interested as to why 2 MCBs. That would require 2 meters. When we have discussed this before it was suggested to run the inverters in parallel at the isolator, then to the meter and on to a single MCB.

Looks a neat job, which, as above bodes well. there should be a second AC isolator at the DB, where you would usually also have the meter. I am guessing there is a space issue there.

6 mm cable is almost certainly fine.
The number od DC isolators suggests each array is split into 2 strings. I don't understand why they would do that. I would have thought each array to a single string to the inverter..

Would the system preform better as one large string as aposed to 2 smaller stirngs ?

personally I would have gone for a single 2 MPPT inverter but thats just a matter of choice.

And yes it is very tidy job that has been done in the loft but only after I had stopes them when they started to do it and ask for it to be done very neat with everything planed out rather than just chucked on so with that they removed the inverters and sorted out the level of the back board.
I just wish the panels where as neat as it is the first thing you seen when you turn the corner into my street. I have been promised that all the panels will get removed and the rails will get lowered and levelled to a flawless standard.

I really want to get the photos up for you guys to see and comment. For all I know he used a cheaper fixing bracket or the wrong fixings and that could be why it is so high off the roof.

 

[BruceB]

To answer Moggy's point on why two mcbs, it is because if you only have a single mcb it might be too big to:
- provide fault protection for the cable to a single inverter;
- provide overload protection for a single inverter; and
- you would not have discrimination.

Now you can argue the detail of all those points in any particular situation, but I cannot think of any other reasons the manufacturers would specify it.

Another point on the installation is that it has been in done an over complex and expensive way (probably because that is what they had on the shelf). As it is east/west with neither side pushing out full power simultaneously then a single 5000TL inverter would have done it. Indeed depending on the precise panels used a 4000TL could do it according to sunny design.