The Siemens SENTRON 3VM9988-0AB13 is a tripped signaling switch with changeover contacts, type HQ, designed as an electronic accessory for 3VM circuit breakers. It occupies 7 mm of DIN-rail width and carries a thermal current rating of 0.3 A. This is a signaling accessory, not a main power path component — it reports the breaker's tripped state via a changeover contact set. The 0.3 A rating covers the signal load, not a motor or heater circuit.
Switching capacity and contact ratings
The changeover contacts are rated 0.3 A at 12 V and 24 V under AC-12 and AC-15 duty classes — the same 0.3 A holds across both resistive and light inductive AC loads at those voltages. For DC switching, the ratings drop: 0.1 A at 12 V and 24 V under DC-12 (resistive), and 0.07 A at the same voltages under DC-13 (solenoid/contactors). The minimum operating voltage is 24 V DC. The 0.07 A DC-13 rating is the limiting case — if the switch signals a DC contactor or solenoid, stay under 70 mA at 24 V. The AC-15 rating at 0.3 A covers most PLC digital input and indicator lamp loads.
Isolation and environmental specs
Rated for overvoltage category III and pollution degree 3, with a surge voltage resistance of 4 kV. Pollution degree 3 means the part tolerates conductive pollution or dry non-conductive pollution that becomes conductive under condensation — typical for control panels in industrial environments without climate control. Overvoltage category III covers fixed-installation downstream of the main distribution board.
Physical fit and wiring
Dimensions: 7 mm wide, 30 mm deep, 56 mm high. The 7 mm width is a single modular DIN-rail unit — it snaps into the same rail as the 3VM breaker it signals. Stripped length is 15 mm (0.6 in) for the connection wires.