Dulas Solar VC150, Handbook

Page: 15 / 156

15
LIGHTNING PROTECTION
MEASURES
LEVEL 1- NO PROTECTIVE MEASURES- NOT RECOMMENDED BY DULAS LTD
Failure to provide protection measures against lightning strike risks damage to the
equipment. In the event of lightning strike the roof mounted solar array, high voltage
may be conducted towards the refrigerator system. This high voltage may damage
the electronic components of the system.
LEVEL 2- LIMITED PROTECTIVE MEASURES (Normally Supplied)
We strongly recommend that at least this level of protection be installed-see figure 1.
Install an earth electrode (earth rod)(A) outside the building-the earth rod should be
at least 2m long. Connect the earth rod with good quality wire (at least 6mm
2
) to
battery positive (wire B) and with separate similar wire to the Solar array and support
structure (wire C). The earth wire should follow the shortest and straightest path
between the support structure and the earth rod.
LEVEL 3 - FULL LIGHTNING CONDUCTOR SYSTEM (Not Supplied)
Assess the risk of lightening strike. Look at other local building- are they fitted with
lightening conductors? Ask local people if TV aerials etc often get struck?
If the installation is at high risk of lightening strike then an additional lightening
conductor and separate earth rod should be installed-see figure 2.
In addition to level 2 protections, install a second earth electrode (D). The distance
between the two earth electrodes must be more than their length. Erect an Air
terminal of Lightning Conductor (E) next to the second earth electrode. The Air
terminal must exceed the height of the Solar Array such that the Solar Array falls
within 45
0
cone centered on the Air terminal-this is the area that is protected by the
Air Terminal.