What it is and what it does
The Siemens 3RT1016-1AP05 is a SIRIUS power contactor in size S00 — the compact frame that fits three across a 45 mm DIN-rail pitch. It switches motor loads up to 5.5 kW at 690 V AC-3, with a 230 V coil rated for both 50 Hz and 60 Hz. The three main poles use screw-type terminals, and the front face is IP20 finger-safe.
Key ratings and what they mean for fit
The 5.5 kW at 690 V AC-3 rating is the motor-switching duty — that's the number to match against your motor nameplate for a standard squirrel-cage induction motor. For the same motor on 400 V, the AC-3 rating drops to 4.5 kW. If your load involves plugging or inching (AC-4 duty), the contactor is rated 8.5 A at 400 V — significantly lower than the AC-3 current, so size up if you need frequent reversing or jogging. The 230 V coil pulls in reliably across 0.8 to 1.1 times rated voltage at 50 Hz, and 0.85 to 1.1 at 60 Hz. That means it holds in down to about 184 V at 50 Hz — useful if your control transformer is lightly loaded or you have long cable runs. Rated for pollution degree 3 and operating temperature -25 to +60 °C, so it's at home in an industrial panel without climate control. The 2000 m maximum altitude rating covers most installations without derating.
Mounting and wiring
Snaps onto a 35 mm DIN rail per EN 50022 and can be mounted side-by-side with zero gap — no derating needed for adjacent contactors at full load. The screw terminals accept 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or up to 2x (0.75 to 4 mm²) per pole. That covers most panel wiring from signal-level control wires up to 4 mm² power tails. The depth is 114 mm, so plan for at least 120 mm of enclosure depth to clear the terminals and any auxiliary block.
Coordination and protection
For Type 2 coordination (no damage to the contactor after a short circuit), Siemens specifies a 20 A gL/gG fuse upstream. For Type 1 coordination (contactor may need replacement after a fault), a 35 A gL/gG fuse is allowed. The auxiliary contacts (1 NO + 1 NC built-in) are rated 10 A at AC-12 for control-circuit loads, and derate to 6 A at 230 V, 3 A at 400 V, and 0.3 A at 220 V DC.