TL inverter

[mikemack00]

Hi

Im sure this question has come up a million times before, so sorry in advance for boring you, did try and search for 'TL inverter' threads but alas it came back with zilch.

ok preamble over, my question is : should we bond a pv array of a TL inverter. Some people say yes, others swear blind that you shouldnt, say it will act as a lightning conductor :banghead:

why is something like this such a grey area, it should be a straight forward yes or no answer. Also if you do need to bond it, what size earth should you use? 10mm?

God help me.

 

[yellowvanman]

Check out DTI Guide - there is a decision tree there to use.

Answer is yes bond and it does recommend 10mm (I think)

 

[jupestar]

i'm firmly in the lightning conductor corner, however i shall obey the DTI guide until they inevitably change it.

 

[moggy1968]

yep 10mm

 

[SibertSolar]

If you're worried about creating a lightning conductor then design-in some surge protection for the DC and AC circuits?

 

[mikemack00]

Thanks chaps, can I run the earth back to the main aerthing terminal in the consumer unit? or should I put in a separate earth stake?

 

[yellowvanman]

Thanks chaps, can I run the earth back to the main aerthing terminal in the consumer unit? or should I put in a separate earth stake?

Depends on the earth provided (TNS, TNCS etc) - again the decision tree in the DTI guide deals with that.

 

[mikemack00]

Yeah cheers yellowvanman, have printedof a copy of it, very usefull.

 

[mikemack00]

I can't seem to get away from this fronius tl inerter, I'm getting an AC over current fault code on the one i installed today 'error 301' just befor it trips out the main switch (rcd protected) of the sub db. have double checked polarity is correct, scratching me head now. Sigh. time for a drink.

 

[GaryM]

IIRC, error 301 is when the voltage of the array falls below an acceptable limit. Was it starting to go dark when you were commissioning?
Whats the rating of the RCD and does there really need to be an RCD protecting it?

 

[mikemack00]

It was cloudy but still lightish, just before 4pm. I dont normally use this rcd protected 2 way board but the assistant at the wholesaler practicly forced it on me. despite asking for a non rcd board. If it gets too dark for the inverter, does it bring up an error message?

 

[yellowvanman]

If the RCD is tripping there either a problem with the inverter or with your wiring. You did do your insulation tests before turning on?

Unplug inverter and turn on ac isolator/rcd etc. if it doesn't trip then the problem is in the inverter.

 

[SolarCity]

The low light error message flashes up on IG TL inverters just before the inverter starts up and just after it shuts off. Nothing to worry about.

 

[moggy1968]

although many inverters specify at least a 100ma RCD (sometimes 300ma) I've only once had a problem with 30ma ones and that was a very old main RCD on one of my first jobs (before I found out about the problems of shared RCDs!)
Generally I only use them when I can't get a garage board without one (there were shortages in the autumn) and the RCD is just acting as a main switch, as you can't use a type A RCD (the ones most commonly found on domestic boards) where the regs require an RCD to be fitted.