Position of rails/clamps

[moggy1968]

thats amoot point solarcity
On my inspection my assessor told me my system didn't need bonding (fronius IGTL inverter)

 

[SolarCity]

thats amoot point solarcity
On my inspection my assessor told me my system didn't need bonding (fronius IGTL inverter)

Fair enough. But he would need to be going by the upcoming guidance to say so as the existing guidance says systems with TL inverters must be bonded.

 

[sedgy34]

if the array isnt accesible it dont need bonding as its classed as floating any works to be done etc the system would be isolated so there you go guys.


could fit transformered inverters then you have voltage seperation

 

[moggy1968]

Fair enough. But he would need to be going by the upcoming guidance to say so as the existing guidance says systems with TL inverters must be bonded.

that was on existing guidence

 

[SolarCity]

if the array isnt accesible it dont need bonding as its classed as floating any works to be done etc the system would be isolated so there you go guys.


could fit transformered inverters then you have voltage seperation

Yet this is contrary to the current Dti guide.

- - - Updated - - -

that was on existing guidence

True, but we are still working to existing guidance, right

 

[wstevew]

Thread takes off again ;-)

Back to topic. Solarcity is right SMA recommended bonding the frame to fix the problem.

I'm not convinced it will fix it either. Neither is my supplier and that is why I believe they are supposedly in contact with SMA. But if the manufacturer insists their TL inverters should be bonded then perhaps it should.

 

[moggy1968]

yep, there is that cover all as discussed before, if the manufacturer says so then so be it!

 

[SolarCity]

I don't see how it would fix it either but my experience of the technical staff at the likes of SMA is that they tend to know their own products. I'd love to hear their explanation for why this should solve the issue.

 

[wstevew]

solar 19-06-2012 pictures by wstevew - Photobucket

Some photo's now, A few of the badly ground out tiles were left due to not having enough tiles having to replace.

 

[SolarCity]

Much better but still not as good as it could have been.

The flu in picture 11 still gives me a little shudder.

 

[Earthstore]

That looks better, no 7 still looks a little thin, but as you say they were short of tiles, so is the mounting side of things ok with you?

As to the bonding/earthing of the array, if SMA say that is what is needed, why don't they just do it, if it cures the problem then great, but if you do not do it and the problem reoccurs, SMA will ask why it has not been bonded.
It will not take them long or cost them much, so I can not understand why they do not do it?

 

[wstevew]

I got to see all the rails/brackets before the panels went on, the brackets are 2 piece, there is an aluminium plate that is screwed to the joist then the bracket is attached by a bolt. he sorted all the rails so all joins were butted up to the rivets. all the rails are even and clamps look attached well.


Originally I emailed SMA asking why would I get the event 601. Their reply suggested they should bond the frame and they should check with the frame manufacturer for appropriate materials. I forwarded this to them.

Then when they come out last week he said he was going to bond to the TWE in the AC Isolator and I told him not too as that was wrong. Then they went and brought some 4mm earth cable and started to run that, I told them to check with their technical man as I said I thought the cable was too thin. Then they started saying that there was no regs to say it had to be bonded and stopped.

I said regulation or not, If the manufacturer says it should be bonded then they perhaps they should. Next time I asked I was told their technical guy was going to call me once he had spoken to SMA, I still have heard nothing back.

I guess they want to know why SMA say it should be bonded, and how it will fix the problem.

"Gavin A" has his suspicions that it could be related to capacitor charge/discharge on the inverter. It happens approx 15 min before/after feed in. It doesn't happen every day so It could be related to the amount light the panels are exposed to before/after feed in.

 

[Gavin A]

another possibility is increased capacitance from the panels, as they get damp with dew.

I'm not really sure about the potential mechanism for this getting through to the grid feed, but bonding the frame would potentially give this a route to earth other than via the inverter.

It's been a while since I looked into this though, and it's stretching the boundaries of what I'm really trained for tbh - Bruce B would probably be a good bet on this, or any other electrical engineer types.

If it's this, then it probably would explain SMA's advice.

 

[Dan]

Don't mind me while I bump some threads in the solar PV forum. If they're not current or applicable topics, just ignore the threads; they'll drop off the page. If they are, feel free to chip in and chat solar stuff in the solar panels forum.