3RW3018-1BB14 Soft starter 7.5 kW, 200-480 V, series 3RW30, Siemens

Siemens SIRIUS 3RW30 Soft Starters — Ultra-Compact Ranges for Basic Starting Duties

The Siemens SIRIUS 3RW30 soft starter family is engineered for three-phase asynchronous motors rated from 1.5 to 55 kW. Representing a highly economical, simple starting solution, the 3RW30 is designed to prevent mechanical shocks on gearboxes and eliminate peak current spikes on the grid. With a frame width of only 45 mm (for capacities up to 15 kW / 32 A), it acts as a direct, space-saving replacement for legacy star-delta contactor assemblies.

Typical Applications for Siemens 3RW30

• Axial and Ventilation Fans: Gradual voltage build-up ensures shock-free acceleration of fan blades, protecting belts and bearings from premature wear.
• Small Inline Air Compressors: Gentle starting ramp limits mechanical loads on drive couplings when initiating start profiles under loaded states.
• Basic Material Conveyors: Prevents damage or tipping of transported items by eliminating sudden startup shocks.

What Differentiates Siemens 3RW30 from Competitors

The 3RW30 is a dedicated, highly cost-efficient solution specifically for starting profiles. By omitting soft stop functionality, it offers B2B buyers premium German engineering at a highly competitive entry-level price point.

When Siemens 3RW30 is NOT Suitable

• In pumping installations where soft stopping is crucial to eliminate pipe stress and water hammer — upgrade to the Siemens 3RW40 series.
• When integrated thermal overload motor protection is required directly inside the soft starter — select the 3RW40.

Our Setup Recommendations

The SIRIUS 3RW30 is a robust, no-nonsense starter. Commissioning is exceptionally easy and does not require digital tools; it uses just two potentiometer knobs to adjust starting voltage and ramp time. Because it does not feature integrated electronic motor protection, it must be paired with a Siemens 3RV20 manual motor starter.