32. GDT for 230VAC Mains Primary Surge Protection

Meera is designing a multi-stage surge protection device (SPD) for a 230VAC industrial power input. 

The GDT will serve as the first stage (primary) protection to handle high-energy lightning surges before the MOV (second stage) clamps the remaining transient. 

Because the GDT is across the 230VAC mains, it must not fire during normal mains voltage including worst-case grid tolerance. 

Key requirements: 

• Mains voltage: 230VAC (peak ~325V, worst-case with tolerance ~360V) 

• GDT spark-over voltage: 470V (above worst-case mains peak, fires only on surge) 

• Surge current: ≥10kA (8/20µs) for heavy lightning surges on mains 

• 2-pole GDT (Line-Neutral) 

• Through-hole package for power-stage mounting 

The company's AVL specifies Littelfuse, so the part must be selected from Littelfuse on DigiKey. 

Help her select a suitable GDT from Littelfuse on DigiKey.