Hugh,

No direct knowledge, but you may find something relevant in the IEE Wiring Regs 
at http://www.theiet.org/publishing/books/wir-reg/17th-edition.cfm, in 
particular Regulation 131.6 (EMC related) and Section 712 (photovoltaic 
systems).  

I don't have a copy (not much use in France) so can't quote from it.  Do you 
have access to a suitable library?

73
John Rabson 
F5VLF
58800 Cervon
France
JN17vg