The Siemens 3VA9988-0AB23 is a SENTRON electrical alarm switch — a 7 mm wide accessory that mounts directly on 3VA1 and 3VA2 molded-case circuit breakers to provide remote indication of breaker trip or alarm conditions. It uses changeover contacts (type HQ) for signaling to a PLC, annunciator, or safety relay.
Switching capability by load type
Rated at 0.3 A across AC-12 and AC-15 at both 12 V and 24 V — meaning it can handle resistive and lightly inductive control loads at panel voltages. For DC circuits, the rating drops: 0.1 A at DC-12 (resistive), and 0.07 A at DC-13 (solenoid/relay loads) at 24 V. That 0.07 A DC-13 figure is the limiting case for most industrial control loops; if your PLC input or relay coil draws more, this switch won't break it reliably.
Insulation coordination and mounting
Overvoltage category III and pollution degree 3 — suitable for the fixed-installation environment inside a panel where the switch sees transient surges up to 4 kV. The 7 mm width means it snaps into the breaker's accessory slot without consuming additional DIN rail space. Depth is 30 mm, height 56 mm, so it stays within the breaker envelope.