With No Lightning Protection System Present
Single Phase - Domestic Installation in High Rise Flats
This example shows a high rise residential block without LPS (Lightning Protection System) installed and the DNO (Distribution Network Operator) Supplied is via underground.
No LPS means that a TYPE 1 / CLASS I SPD is not required, how ever a TYPE 2 / CLASS II SPD should be installed to prevent damage to any electronics within the building from transient overvoltages created by non atmospheric conditions, eg: switching surges etc.
A secondary TYPE 2 / CLASS II SPD should also be considered due to equipment distance from original source of protection and the risk of damage should the incoming SPD sacrifices itself and leave the installation with no protection.
We would always recommend a co-ordinated approach where further, downstream protection is installed to prevent damage to sensitive equipment connected to consumer units.