1. SPD shall be installed as close as possible to the protected equipment. The distance shall be less than 10m. 

2. SPD must be reliably grounded. The ground wire of protected equipment shall be connected to SPD first and then grounded through SPD.

3. SPD shall be connected to the main equipotential bonding bar in a distance as short as possible. For example, for power supply SPD, the length of grounding wire (“L” in the figure below) shall be less than 0.5m. 

4. The cross-sectional area of the grounding wire should be big enough to match the discharge capacity of SPD. 

5. When installing series SPD (mostly signal SPD), attentions shall be paid to the direction of SPD. The output of SPD shall always be connected to the equipment protected.