The Siemens 3RT1355-6AR36 is a SIRIUS-branded contactor in size S6, designed for switching loads in industrial control panels. It carries an AC coil rated 250-500 V, drawing 16 VA at both 50 and 60 Hz. The contactor includes two instantaneous normally-open auxiliary contacts, with ratings from 3 A at 24 V up to 4 A at 230 V and 2 A at 690 V.
Key Ratings and What They Mean
The AC coil accepts 250-500 V, covering common 277 V and 400-480 V control circuits without a separate transformer. Pickup voltage is 80% of rated value, dropout is 110% — meaning the coil pulls in reliably at 200 V on a 250 V tap and drops out cleanly at 550 V on a 500 V tap, avoiding chatter on a sagging line. The two NO auxiliary contacts are rated across a wide voltage range: 3 A at 24 V, 1.5 A at 48 V, 0.55 A at 110-125 V, 0.3 A at 220 V, 4 A at 230 V, 3 A at 400 V, and 2 A at 500-690 V. That covers PLC inputs, relay coils, and indicator lamps at whatever control voltage the panel uses. Operating temperature range is -40 to +60 °C during operation, with storage from -40 to +70 °C. That suits unheated enclosures in cold climates and warm cabinets near process equipment.
Mounting and Integration
Mounts via screw fixing on a vertical surface, with ±180° rotation and ±30° tilt forward/backward at 0° rotation. That gives flexibility for tight enclosures where the contactor must sit at an angle to clear other gear. Dimensions are 150 mm height, 120 mm width, 128 mm depth. Plan for 10 mm clearance above and below, 20 mm forward, and 10 mm at the sides for airflow and wiring access. The coil terminals are screw-type, accepting 1x or 2x conductors from 1 to 4 mm² solid or stranded. Operating times are 40-70 ms for both AC and DC coil supplies — consistent enough for sequencing interlocks without special timing logic.
Peer Comparison
Compared to the 3RT1055-6AU36, the 3RT1355-6AR36 is a size S6 contactor with a higher coil voltage range (250-500 V AC vs the smaller frame's typical 24-240 V range). The 3RT1355-6AR36 also carries two NO auxiliary contacts as standard, where the 3RT1055-6AU36 may require a separate auxiliary block. If your panel runs on 400-480 V control power, the 3RT1355-6AR36 eliminates a step-down transformer.