Surge Protector Installation Spacing And Energy Matching Issues
Spacing and Energy Matching Issues
When installing a surge protective device (SPD), consider the energy matching between the two stages. Generally, when SPDs are installed at multiple locations on a line and accurate data is unavailable, the line length between a voltage-switching SPD and a voltage-limiting SPD should not be less than 10 meters, and the line length between voltage-limiting SPDs should not be less than 5 meters. The following points should also be noted:
When a surge protector uses a low-high configuration, the second-stage SPD is almost useless. However, a high-low configuration can provide current shunting.
As the distance between the two poles decreases, the current shunting effect of the front stage decreases, while the current and energy passing through the rear stage increase. When the distance is too close, the front stage becomes almost ineffective. In this case, decoupling measures should be implemented between the two stages. For example, installing an inductive impedance device between the two surge protection device can provide decoupling.
