ATEX-certified soft starter for hazardous-area motor control
The Siemens 3RW5515-3HA14 is a soft starter rated 200-480 V with ATEX and IECEx certification, meaning it can be deployed in Zone 1/21 and Zone 2/22 hazardous areas where flammable gases, vapors, or dusts may be present — the certification covers the starter enclosure and its internal arc-fault containment, not just the motor circuit. Trip class is selectable CLASS 10A / 10E (default) / 20E / 30E per IEC 60947-4-2, which sets the maximum permissible stall time before the overload protection trips — CLASS 10A protects standard squirrel-cage motors with short acceleration times, while CLASS 30E suits high-inertia loads like centrifuges or crushers that need a longer ramp.
Fieldbus integration and control flexibility
Supports PROFIBUS, Modbus RTU, Modbus TCP, and EtherNet/IP on the same unit — no separate communication module needed for these four protocols, which simplifies BOM and reduces panel wiring when the starter talks to a PLC or DCS over a single fieldbus drop. Analog output is configurable as 4-20 mA (default) or 0-10 V, providing real-time motor current or torque feedback to the control system without an external transducer — useful for trending load changes or verifying that the breakaway pulse cleared a jam. Event list and error logbook are stored onboard, so a commissioning engineer can pull the last 4 parameterizable fault records via the fieldbus or the local HMI without needing a laptop — speeds up fault diagnosis on a line-down call.
Motor protection and starting features for demanding loads
Service factor 1.15 allows the starter to handle continuous overload up to 115% of the motor nameplate rating without tripping — critical for applications like pumps or fans that occasionally run above the FLA during process upsets. Torque control with a breakaway pulse delivers a short, high-torque burst at start to break loose sticky loads (e.g., conveyors with frozen bearings or mixers with settled solids), then ramps down to the set torque limit — reduces mechanical shock compared to a fixed voltage ramp. Pump ramp down and DC braking are built in — pump ramp down avoids water hammer on pump stop by gradually reducing voltage, while DC braking stops the motor quickly without a mechanical brake for applications like centrifuges or saws.
Mounting and panel integration dimensions
Overall dimensions are 275 mm height x 170 mm width x 152 mm depth, with required clearances: 100 mm above, 75 mm below, 10 mm forward, 5 mm sideways, and 0 mm backward — the zero backward clearance means it can be mounted flush against the back panel, saving depth in a shallow enclosure. Solid connections accept two conductors per terminal: 1.0-2.5 mm² and 2.5-10 mm², which covers standard motor power cabling up to 10 mm² for the line and load connections without needing a separate terminal block.