10. GDT, Spark Gaps & Hybrid SPDs · Page 1 of 5
Spark Gap / Switching-Type SPDs
High-energy diversion for Type 1 duties.

How they behave
Switching-type elements go from insulating to conducting when voltage exceeds sparkover, diverting large lightning impulse currents.
Strengths
Excellent for high Iimp duties at service entrances.
Design notes
Follow-up current and coordination with upstream protection must be considered in the design.
