Array Earthing help please!!!!!!!!

[ian81]

Im after some advice, Weve installed about 10 systems all the same mitsubishi 225w panels x 6, sunnyboy sb1200 inverter. A representative of the scheme that these were installed for had thier own system installed by another company who earth bonded the array and said that all of our installs were incorrect and should be bonded. I spoke to NICEIC and they said if it was above 2m odd, according to regs cant remeber exact height without checking!!!, then we needent worry and NAPIT's response was almost exactly the same. I found out that they had ran a 10mm earth cable. im in a bit of a grey area at the moment as im not sure what is right and what is wrong. Some people are saying it needs to be done others are saying it doesnt !!!!!!!!! Any help would be much appreciated.

 

[yellowvanman]

Page 22 of the DTI guide to installing PV systems gives you a decision tree on whether bonding is required or not. If you haven't got a copy or can't find it then PM me for a copy.

 

[JamieK]

Hello Ian

My understanding is that the array only needs to be bonded if it is in the equipotential zone (i.e. there is a skylight on the roof and a person could reach out and touch the array) and you are using a transformer-less inverter.

In fact, all arrays must be earthed if you use a transformer-less inverter - I was told best way to avoid the earthing issue is to always user a transformer-ed inverter as then there is physical separation of the DC and AC voltage in the inverter and no fault path exists.