How to Choose the Right Surge Protective Device (SPD) for Your Installation

Surge protective devices (SPDs) divert dangerous voltage spikes caused by lightning and switching surges, shielding your equipment from damage.

Types of SPD

• Type 1 – installed at the main distribution board for direct lightning exposure.
• Type 2 – the most common choice, protecting sub-distribution boards.
• Type 3 – point-of-use protection near sensitive loads.

Key parameters

Look at maximum discharge current (Imax), nominal discharge current (In) and voltage protection level (Up). Walax SPDs are available from 20kA to 80kA with replaceable modules for easy maintenance.