It mates with 3VA1 and 3VA20 through 3VA25 breakers, wired into the control circuit to protect motor and feeder loads against brownout or loss-of-phase conditions that could stall a contactor or overheat a winding.
The 4 kV surge voltage resistance (overvoltage category III) means it withstands switching transients on the distribution side — typical for a panel fed from a 400/480 V transformer.
Physical integration and panel space
The 3VA9908-0BB25 measures 65.1 mm high, 25.7 mm wide, and 28.8 mm deep — a compact footprint that clips into the breaker's accessory slot without consuming extra DIN-rail width. The 10 mm stripped length (0.4 in) on the wiring terminals matches standard ferrule preparation for 1.5 mm² control wiring.