Motor starting in hazardous zones
The 3RW5075-2AB14: It carries ATEX, IECEx, and UKEX approvals, meaning it can be installed in explosive-gas or dust atmospheres where an uncontrolled motor start could ignite the environment — a common requirement in tire curing, chemical processing, and oil & gas applications.
Trip class and motor protection profile
The unit offers selectable trip classes per IEC 60947-4-2: CLASS 10A, 10E (preset), and 20E. Class 10A protects standard squirrel-cage motors during start-up, while 20E accommodates higher-inertia loads like centrifuges or large fans that need a longer acceleration ramp without nuisance tripping. It includes voltage ramp, soft torque, and pump ramp down — the pump ramp down feature gradually reduces torque during stop to prevent water hammer in pumping systems. Torque control is not available on this variant. The analog output is configurable as 4-20 mA (default) or 0-10 V, settable via the High Feature HMI accessory. An error logbook is available only with special accessories.
Fieldbus and control integration
This soft starter supports PROFIBUS, Modbus RTU, Modbus TCP, and EtherNet/IP, plus PROFIenergy in conjunction with a PROFINET communication module. The wide protocol choice lets it drop into existing plant networks without a gateway — whether the line uses Siemens S7, Rockwell ControlLogix, or Modbus-based SCADA. Remote reset is achieved by cycling the control supply voltage. Auto-reset is also available, which is useful for remotely monitored installations where a manual reset walk is undesirable.
Mounting and environmental limits
The unit is screw-fixed, not DIN-rail snap-on, with dimensions 230 mm height, 160 mm width, and 282 mm depth. Clearance requirements: 100 mm upwards, 10 mm forwards, 75 mm downwards, 5 mm at the sides, and 0 mm backwards — plan the panel layout accordingly to maintain airflow and service access. Shock resistance is 15 g / 11 ms, dropping to 12 g / 11 ms with potential contact lifting — relevant for installations on vibrating machinery or near press equipment.
The 3RW5075-2AB14 carries CE marking, UL approval, and CSA approval. The ATEX, IECEx, and UKEX certifications are listed as present, covering installation in Zone 1/21 or Zone 2/22 hazardous areas per the applicable directives.