The Siemens 3VA9988-0BF21 is a fixed-delay time-delay device from the SENTRON accessory range, designed specifically for use with 3VA undervoltage releases at 110V AC. It provides a minimum OFF-delay time of 100 ms, which means that after the undervoltage release trips, the load stays disconnected for at least that window before the release can reset — critical for ride-through coordination in a selective distribution scheme. This is a panel-mounted accessory, sized to snap into the 3VA breaker footprint alongside the release it serves.
Dimensions & Integration
The accessory measures 72.3 mm deep, 44.8 mm wide, and 57.5 mm high — a compact footprint that fits within the 3VA breaker's accessory bay. The 10 mm stripped length on the wiring tails matches standard ferrule and terminal-block preparation for panel wiring.