How to Select and Size a Soft Starter for a Motor
How to size a soft starter correctly by full-load current, IEC 60947-4-2 duty class, starting torque against the load, control method, wiring topology and...
Siemens 3RW30 soft starters are compact and cost-effective motor starting solutions designed for basic soft starting of three-phase asynchronous motors in standard industrial applications. The 3RW30 series focuses on reducing mechanical stress and limiting inrush current during motor start-up, providing a simple and reliable alternative to direct-on-line starting. With a straightforward design and easy commissioning, Siemens 3RW30 soft starters are well suited for pumps, fans, compressors, conveyors, and other simple motor-driven machines where basic motor starting control is sufficient.
The Siemens 3RW3018-1BB14 is a SIRIUS 3RW30 soft starter specified for small three-phase motors up to 7.5 kW (at 400 V). It is designed for use on supply systems from 200 to 480 V AC and has a rated operational current of 17.6 A (specified at 40 °C). Control voltage for this SKU is 110–230 V AC/DC, making it compatible with common industrial control supplies. Typical applications include starting pumps, fans, compressors and small conveyor drives where limiting inrush current and reducing mechanical stress at start-up are required. The compact S00 size and DIN-rail / screw mounting options make the unit suitable for space-constrained control panels and retrofit installations. This model is intended for straightforward soft starting duties and provides the electrical ratings and control-voltage flexibility expected for basic industrial motor starting tasks.
| product brand name | SIRIUS |
|---|---|
| product designation | Soft starter |
| product feature: integrated bypass contact system | Yes |
| product feature: thyristors | Yes |
| product function: intrinsic device protection | No |
| product function: motor overload protection | No |
| product function: evaluation of thermistor motor protection | No |
| product function: external reset | No |
| product function: adjustable current limitation | No |
| product function: inside-delta circuit | No |
| product component motor brake output | No |
| insulation voltage rated value | 600 V |
| degree of pollution | 3, acc. to IEC 60947-4-2 |
| blocking voltage of the thyristor maximum | 1 200 V |
| reference code according to EN 61346-2 | Q |
| reference code according to DIN 40719 extended according to IEC 204-2 according to IEC 750 | G |
| operational current: at 40 °C rated value | 17.6 A |
|---|---|
| operational current: at 50 °C rated value | 17 A |
| operational current: at 60 °C rated value | 14 A |
| at 230 V: at standard circuit at 40 °C rated value | 4 kW |
| at 400 V: at standard circuit at 40 °C rated value | 7.5 kW |
| yielded mechanical performance [hp] for 3-phase AC motor at 200/208 V at standard circuit at 50 °C rated value | 3 hp |
| operating frequency rated value | 50 ... 60 Hz |
| relative negative tolerance of the operating frequency | -10 % |
| relative positive tolerance of the operating frequency | 10 % |
| operating voltage at standard circuit rated value | 200 ... 480 V |
| relative negative tolerance of the operating voltage at standard circuit | -15 % |
| relative positive tolerance of the operating voltage at standard circuit | 10 % |
| minimum load [%] | 10 % |
| continuous operating current [% of Ie] at 40 °C | 115 % |
| power loss [W] at operational current at 40 °C during operation typical | 4 W |
| type of voltage of the control supply voltage | AC/DC |
|---|---|
| control supply voltage frequency 1 rated value | 50 Hz |
| control supply voltage frequency 2 rated value | 60 Hz |
| relative negative tolerance of the control supply voltage frequency | -10 % |
| relative positive tolerance of the control supply voltage frequency | 10 % |
| control supply voltage 1 at AC at 50 Hz | 110 ... 230 V |
| control supply voltage 1 at AC at 60 Hz | 110 ... 230 V |
| relative negative tolerance of the control supply voltage at AC at 50 Hz | -15 % |
| relative positive tolerance of the control supply voltage at AC at 50 Hz | 10 % |
| control supply voltage 1 at DC | 110 ... 230 V |
| display version for fault signal | red |
| Part number | 3RW3018-1BB14 |
|---|---|
| Brand | Siemens |
| Condition | New, factory sealed |
| Source | Siemens and its authorised distributors |
| Warranty | Manufacturer warranty |
| Lifecycle status | Active, in production |
| EAN | 4011209719668 |
| ETIM class | EC000640 |
| eCl@ss | 27370907 |
| size of engine control device | S00 |
|---|---|
| width | 45 mm |
| height | 95 mm |
| depth | 150 mm |
| fastening method | screw and snap-on mounting |
| mounting position | With vertical mounting surface +/-10° rotatable, with vertical mounting surface +/- 10° tiltable to the front and back |
| required spacing with side-by-side mounting: upwards | 60 mm |
| required spacing with side-by-side mounting: at the side | 15 mm |
| required spacing with side-by-side mounting: downwards | 40 mm |
| wire length maximum | 300 m |
| number of poles for main current circuit | 3 |
| type of electrical connection: for main current circuit | screw-type terminals |
|---|---|
| type of electrical connection: for auxiliary and control circuit | screw-type terminals |
| number of NC contacts for auxiliary contacts | 0 |
| number of NO contacts for auxiliary contacts | 1 |
| number of CO contacts for auxiliary contacts | 0 |
| type of connectable conductor cross-sections for main contacts for box terminal using the front clamping point: finely stranded with core end processing | 2x (1 ... 2.5 mm2), 2x (2.5 ... 6 mm2) |
| type of connectable conductor cross-sections for AWG cables for main contacts for box terminal: using the front clamping point | 2x (16 ... 10) |
| type of connectable conductor cross-sections for auxiliary contacts: solid | 2x (0.25 ... 2.5 mm2) |
| installation altitude at height above sea level | 5 000 m |
|---|---|
| environmental category: during transport according to IEC 60721 | 2K2, 2C1, 2S1, 2M2 (max. fall height 0.3 m) |
| environmental category: during storage according to IEC 60721 | 1K6 (only occasional condensation), 1C2 (no salt mist), 1S2 (sand must not get inside the devices), 1M4 |
| environmental category: during operation according to IEC 60721 | 3K6 (no formation of ice, no condensation), 3C3 (no salt mist), 3S2 (sand must not get into the devices), 3M6 |
| ambient temperature: during operation | -25 ... +60 °C |
| ambient temperature: during storage | -40 ... +80 °C |
| derating temperature | 40 °C |
| protection class IP on the front according to IEC 60529 | IP20 |
| touch protection on the front according to IEC 60529 | finger-safe, for vertical contact from the front |
| at 220/230 V: at standard circuit at 50 °C rated value | 3 hp |
|---|---|
| at 460/480 V: at standard circuit at 50 °C rated value | 10 hp |
| contact rating of auxiliary contacts according to UL | B300 / R300 |
| Environmental Product Declaration: global warming potential [CO2 eq] / during manufacturing | 11.1 kg |
|---|
| Net weight | 0.436 kg |
|---|---|
| Package dimensions | 165 × 123 × 60 mm |
| Country of origin | CZ |
| Shipping weight | 0.936 kg |
| Ships from | Türkiye |
| Dispatch | 12 Nov |
| Stock | In stock |
Source: manufacturer data · Last verified: 30 Oct 2026
No documents are on file for this part yet.
Ask us for the datasheetThe rated current of 3RW3018-1BB14 is 17.6 A.
The rated operational voltage of 3RW3018-1BB14 is 200–480 V AC.
The rated motor power of 3RW3018-1BB14 is 7.5 kW.
The control voltage range of 3RW3018-1BB14 is 110–230 V.
The tariff (HS) code on file for 3RW3018-1BB14 is 853710.
The EAN (GTIN) of 3RW3018-1BB14 is 4011209719668.
3RW3018-1BB14 ships from Türkiye. Shipping calculated at checkout · import duties and taxes paid on arrival. Stock items are dispatched within 1–2 business days.
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