What it is and what it does
The Siemens 3RB3016-2SB0-ZX95 is a SIRIUS solid-state overload relay, size S00, designed for motor protection in control panels. It's rated for a thermal current of 12 A and a rated value of 690 V, with a trip class of CLASS 20E — meaning it'll let a motor pull starting current for up to 20 seconds before tripping, which covers most standard induction motor starts without nuisance trips. The electronic overload release gives you temperature compensation from -25 to +60 °C, so it won't drift on a hot summer day out on the plant floor.
How it fits and mounts
Mounts directly onto a contactor via the fastening method specified — no DIN rail needed, though it can sit in any mounting position. The footprint is 45 mm wide, 79 mm high, and 73 mm deep, so it takes up about the same panel space as a standard contactor add-on. Wiring is via screw-type terminals on the main current circuit, accepting 1x 0.5 to 4 mm² or 2x 0.5 to 2.5 mm² solid or stranded copper. The screwdriver tip needed is a Pozidriv PZ2 with a shaft diameter of 5 to 6 mm — keep that on the cart, not a flathead.
Ratings and what they mean for the line
The auxiliary switch is integrated and carries its own ratings: 2 A at 24 V, 4 A at 120 V, 3 A at 230 V. That's the signal side — the one that tells the PLC or the HOA switch that the relay has tripped. The main contacts are M3 screw terminals. For vibration, it's rated 1–6 Hz at 15 mm amplitude and 6–500 Hz at 20 m/s² for 10 cycles; shock resistance is 15g for 11 ms on the main contacts, though the signaling contact in tripped position drops to 9g. That means if you're mounting this on a contactor that's on a vibrating pump skid, the trip signal might chatter under heavy shock — something to watch if you're relying on that 97/98 contact for a safety interlock.