Published: 7 April 2014
Category: Q&A
John asks this question, which concerns lightning protection and earthing arrangements for a building’s metal roof covering. It has been answered by SELECT (Theme – Fire, Safety and Security):
This Q & A is one of thousands posted in our Technical Expertise area, and answered on a daily basis by our Voltimum Experts.
Question: I’m currently installing the wiring system for a new build stand alone village hall. The roof covering for the hall is zinc coated steel sheeting with an eight-panel solar PV array on one side.
Does this type of roof covering require lightning protection?
Or does it need to be earthed to the mains earth terminal?
The reason for asking is there is no provision for any type of roof earthing on the architect’s drawing.
Answer: Although BS 7671 excludes lightning protection systems from its scope, there is a requirement in Regulation 411.3.1.2 to provide a protective bonding connection of such systems to the main earthing terminal of the electrical installation, in accordance with BS EN 62305.
As is pointed out in the IET Guidance Note 8 (Earthing and Bonding), the positioning of any such protective bonding is best determined by a lightning protection engineer.
Likewise, the need (or otherwise) for a lightning protection system to be provided for any given building should also be decided by a lightning protection engineer.
To see many more Q & A in Voltimum UK's Experts Area, please click on the link. Experts from leading organisations provide online answers to your technical questions on a broad range of subjects. Our searchable database of existing Q & As now contains over 3,500 entries; you can browse through them here.
