28/05/2026
Unlike AC circuits, PV DC systems have no natural zero-crossing point — making DC arcs extremely hard to extinguish.
When selecting DC SPDs for 1000V / 1500V PV systems, relying only on Imax (40kA) is not enough.
Here’s what you must verify:
Thermal Disconnection Mechanism:
MOVs can go into thermal runaway under TOV or prolonged stress. Without a dedicated arc-extinguishing thermal trip, your SPD could become a fire hazard inside the combiner box.
Iscpv Rating:
Always confirm the SPD’s short-circuit current rating matches the maximum fault current of your PV strings.
