Soft Starter
Semiconductor motor controller for limiting starting current and smoothly controlling voltage, torque, or current during starting and stopping.
A soft starter reduces electrical and mechanical stress during motor starting by controlled voltage variation and/or current limitation.
Depending on design, two or three phases may be controlled and algorithms may include voltage ramp, current limit, torque control, Kick Start, and different soft-stop modes.
Key parameters include initial-voltage range, current limit, start and stop ramp times, starts per hour, duty cycle, and thermal capability. After starting, the power semiconductors may be bypassed by an integrated or external bypass contactor.
Advanced versions may support bypass monitoring, diagnostics, different connection methods, and additional braking methods. Selection considers motor current and power, load characteristic, start duration and frequency, connection arrangement, and declared compliance with applicable IEC/EN/UL/CSA 60947-4-2 requirements.
Semiconductor soft starters for induction motors and compatible motor loads, with integrated or external bypass.
Soft Starter
Dimensions4
External horizontal dimension of the product between its outermost lateral points.
External vertical dimension of the product from its lowest to its highest point.
External distance between the foremost and rearmost surfaces of the product.
Mass of the product itself, excluding transport packaging, additional accessories, and external equipment.
Materials and Finish7
Primary material from which the product is manufactured.
Grade, alloy, class, or technical designation of the product's primary material.
Primary visually perceived colour of the product's external surface.
Designation of the product's primary surface colour according to the RAL colour system.
Type of final surface finish of the product determining its appearance and service properties.
Technological surface treatment applied to modify its protective, mechanical, or decorative properties.
Type of protective, functional, or decorative coating applied to the surface.
Mounting and Installation29
Installation arrangement permitted by the product design, such as wall-mounted, flush-mounted, floor-mounted, or another specified mounting type.
Method used to mechanically secure the product to a support, surface, or load-bearing structure.
Type of surface or supporting base to which the product may be fixed.
Permissible spatial orientation of the component during installation and operation.
Number of holes provided in the product for mechanical fixing.
Diameter of the hole provided for a fixing element used when mounting the product.
Distance between the centres of mounting holes in the horizontal direction.
Distance between the centres of mounting holes in the vertical direction.
Horizontal dimension of the mounting pattern between the outermost fixing points of the product.
Vertical dimension of the mounting pattern between the outermost fixing points of the product.
Size designation of the screw, bolt, or other threaded fastener used for mounting the product.
Designation of the thread provided in the product's mounting holes or fixing elements.
Tightening torque recommended or permitted for fasteners during product installation.
Indicates whether the required fasteners are included with the product.
Indicates whether the design provides for mounting equipment on a DIN rail.
Indicates whether equipment may be mounted directly to the mounting surface without an intermediate DIN rail.
Minimum free space required above the product for installation, cooling, or servicing.
Minimum free space required below the product for installation, cooling, or servicing.
Minimum free space required to the left of the product for installation or servicing.
Minimum free space required to the right of the product for installation or servicing.
Minimum free space required in front of the product for installation and normal operation.
Minimum free space required behind the product for installation and normal operation.
Maximum angle permitted by the manufacturer by which the product may deviate from the specified reference orientation during installation.
Minimum unobstructed installation clearance required above the product for ventilation or heat dissipation.
Minimum unobstructed installation clearance required below the product for ventilation or heat dissipation.
Minimum unobstructed installation clearance required on the left side for normal cooling.
Minimum unobstructed installation clearance required on the right side for normal cooling.
Minimum unobstructed installation clearance required in front of the product for normal cooling.
Minimum unobstructed installation clearance required behind the product for normal cooling.
Electrical Parameters58
Type of electrical current for which the product's main supply circuit is intended.
Voltage value assigned to the product by the manufacturer for specified application conditions and characteristics.
Operating-circuit voltage with reference to which the product's performance characteristics are specified.
Minimum voltage at which the manufacturer guarantees the intended operating mode of the product.
Maximum voltage at which continuous operation of the product is permitted under the conditions declared by the manufacturer.
AC frequency assigned to the product for normal operating conditions.
Lower limit of the electrical network or signal frequency at which product operation is permitted.
Upper limit of the electrical network or signal frequency at which product operation is permitted.
Current assigned to the product by the manufacturer for the declared operating and thermal conditions.
Current that the product can carry continuously under the manufacturer's declared conditions without exceeding permissible temperature rise.
Voltage with reference to which the product's insulation clearances and dielectric properties are specified.
Peak value of an impulse voltage of specified waveform that the product insulation must withstand without breakdown.
Test voltage applied to verify the dielectric strength of the product insulation.
Minimum permissible insulation resistance between the specified electrically separated parts.
Category characterizing the expected level of impulse overvoltages at the product's point of use.
Degree of pollution of the surrounding microenvironment considered when selecting insulation distances and product characteristics.
Class of protection against electric shock determined by the product design and protective connection method.
Motor technologies and motor types that the product is designed to control, start, protect or drive.
Electrical phase configurations of motors supported by the product.
Motor winding connection configurations supported by the product.
Minimum motor rated voltage supported by the product.
Maximum motor rated voltage supported by the product.
Minimum motor rated current supported by the product.
Maximum motor rated current supported by the product.
Minimum motor rated power supported by the product.
Maximum motor rated power supported by the product.
Minimum motor rated frequency supported by the product.
Maximum motor rated frequency supported by the product.
Minimum motor rated rotational speed supported by the product.
Maximum motor rated rotational speed supported by the product.
Minimum number of motor poles supported by the product.
Maximum number of motor poles supported by the product.
Minimum motor service factor supported or configurable for motor protection or control.
Maximum motor service factor supported or configurable for motor protection or control.
Motor starting methods that the product can provide or manage.
Motor stopping and braking methods supported by the product, including coast stop, controlled deceleration and electrical, regenerative or mechanical braking methods.
Motor rotation directions that the product can control.
Manufacturer-declared motor power associated with the stated operational voltage and utilization category. UI may display the value in kW.
Operational voltage associated with the stored rated motor power.
Utilization category to which the stored rated motor power applies.
Conductor connection technology used specifically for the main power terminals of the switching device.
Minimum conductor cross-section accepted by the main power terminal.
Maximum conductor cross-section accepted by the main power terminal.
Manufacturer-declared tightening torque specifically for screw, bolt or clamp-type main power terminals.
Conductor connection technology used specifically for the control-circuit terminals.
Minimum conductor cross-section accepted by the control-circuit terminal.
Maximum conductor cross-section accepted by the control-circuit terminal.
Manufacturer-declared tightening torque specifically for a screw-type control-circuit terminal.
Number of motor supply phases in which the soft starter actively controls voltage using its semiconductor power stage.
Motor-circuit connection arrangements supported by the soft starter, such as in-line and inside-delta connection.
Indicates that the initial motor voltage at the beginning of the starting ramp can be adjusted.
Minimum configurable initial motor voltage expressed as a percentage of the applicable line or rated motor voltage.
Maximum configurable initial motor voltage expressed as a percentage of the applicable line or rated motor voltage.
Manufacturer-declared starting current associated with the rated soft-starter starting duty, expressed as a percentage of the applicable rated motor or starter current.
Manufacturer-declared maximum or reference motor starting duration associated with the stated starting-duty rating.
Minimum required interval between consecutive motor starts under the manufacturer-declared duty conditions.
Manufacturer-declared proportion of the complete operating cycle during which the product carries load current under the stated duty or utilization rating.
Maximum permitted or configurable number of motor starts within one hour.
Protection and Safety13
Degree of enclosure protection against access to hazardous parts and ingress of solid objects and water, designated by the IP code.
IP degree of protection provided by the accessible front side of the product after its intended installation.
Class of enclosure resistance to external mechanical impacts designated by the IK code.
Indicates whether the declared ingress protection of the enclosure has been verified by certification or testing.
Method or level of protection of the user against direct contact with hazardous live parts.
Set of protection functions integrated into the product or provided by it in its normal intended configuration.
Reset or restart modes supported after the condition that caused a trip, protection action, alarm or safety stop has been cleared.
Indicates whether a local mechanical or electronic indicator shows that the circuit breaker has tripped protectively.
Manufacturer-declared permissible short-circuit current value for the product or assembly under specified conditions.
Conditions associated with the declared short-circuit withstand rating or SCCR, including required type, class, rating, or other restrictions of the upstream protective device.
Indicates that motor starting current can be limited to a configurable multiple or percentage of the motor current reference.
Minimum configurable motor current limit expressed as a percentage of the applicable motor full-load or rated-current reference.
Maximum configurable motor current limit expressed as a percentage of the applicable motor full-load or rated-current reference.
Environmental Conditions27
Minimum ambient temperature at which normal operation of the product is permitted.
Maximum ambient temperature at which normal operation of the product is permitted.
Minimum ambient temperature permitted during storage of the product while not in operation.
Maximum ambient temperature permitted during storage of the product while not in operation.
Minimum relative air humidity permitted for the declared operating or test condition.
Maximum relative air humidity permitted for the declared operating or test condition.
Temperature at which the corresponding relative humidity value is specified or standardized.
Nature of the humidity conditions for which product operation or resistance is declared.
Indicates whether the permissible humidity value applies only to non-condensing conditions.
Maximum altitude above sea level at which the product may be installed without exceeding the declared conditions.
Indicates whether the permissible product load must be reduced as installation altitude increases.
Altitude above sea level above which the permissible product load must be reduced.
Indicates whether the product's resistance to vibration has been verified under the declared conditions.
Lower limit of vibration frequency applied or permitted in the relevant test.
Upper limit of vibration frequency applied or permitted in the relevant test.
Amplitude or test-method-specified acceleration of vibration applied during product testing.
Indicates whether the product's resistance to short-duration mechanical shocks has been verified.
Maximum acceleration generated during mechanical shock testing of the product.
Duration of an individual mechanical shock pulse during product testing.
Primary cooling method used by the product during normal operation.
Maximum manufacturer-declared acoustic noise level under the specified operating and measurement conditions.
Principal airflow direction through or around the product for normal manufacturer-declared cooling.
Percentage reduction of usable output capability per kelvin above the manufacturer-declared derating threshold.
Percentage reduction of usable output capability per 1000 metres above the manufacturer-declared derating altitude.
Indicates that one or more internal printed circuit boards are protected by a conformal coating.
Principal conformal coating material applied to internal printed circuit boards.
Indicates that the product incorporates manufacturer-declared measures intended for operation in hot and humid tropical environments.
Included Equipment2
Indicates that the soft starter incorporates an internal bypass contactor that carries motor current after starting.
Indicates that the manufacturer supports operation with an external bypass contactor.
Special Features38
Number of available digital inputs of the product.
Number of available digital outputs of the product.
Indicates whether user-configurable functions can be assigned to one or more digital inputs.
Indicates whether user-configurable functions can be assigned to one or more digital outputs.
Number of independent relay outputs or sets of switching contacts provided by the product.
Contact configurations provided for the product relay outputs.
Functions permanently assigned or assignable to the product relay outputs.
Number of integrated analogue input channels.
Analogue signal, sensor or resistance input types supported by the product.
Number of integrated analog outputs provided by the product.
Types of analog signals supported by the product outputs.
Indicates whether the product supports digital data exchange with external devices or systems.
List of supported digital data communication protocols.
List of supported physical or logical digital communication interfaces.
Indicates whether the product can store an internal event log.
Maximum number of event records that can be stored in the product's internal log.
Indicates whether accumulated product operating time or loaded operating time is counted according to the manufacturer's definition.
Indicates whether the number of protective trips of the product is counted.
Indicates whether the product performs internal diagnostic checks to detect or report internal faults.
Control algorithms supported during motor acceleration and starting.
Controlled motor stopping methods supported by the soft starter.
Indicates that the acceleration or starting ramp duration can be adjusted.
Minimum configurable starting ramp duration.
Maximum configurable starting ramp duration.
Indicates that the controlled deceleration or soft-stop ramp duration can be adjusted.
Minimum configurable controlled stopping ramp duration.
Maximum configurable controlled stopping ramp duration.
Indicates that an initial motor starting-torque reference can be adjusted.
Minimum configurable initial torque reference expressed as a percentage of the applicable motor torque reference.
Maximum configurable initial torque reference expressed as a percentage of the applicable motor torque reference.
Indicates support for a short elevated starting command used to overcome high static friction or difficult initial load breakaway.
Minimum configurable kick-start voltage, torque or manufacturer-defined starting level expressed as a percentage of its applicable reference.
Maximum configurable kick-start voltage, torque or manufacturer-defined starting level expressed as a percentage of its applicable reference.
Minimum configurable kick-start duration.
Maximum configurable kick-start duration.
Indicates that transfer between semiconductor control and bypass operation occurs automatically.
Indicates that bypass-contactor state can be monitored or verified by the soft starter.
Indicates that a dedicated output is provided for controlling an external bypass contactor.
Standards and Compliance20
Primary normative document or standard according to which the manufacturer classifies or assesses the product.
Additional normative documents and standards declared by the manufacturer as applicable to the product.
Indicates whether an official declaration of conformity is available for the product.
Indicates whether a certificate relating to the declared certification or conformity of the product is available.
Indicates whether the CE marking is applied to the product where applicable.
Indicates whether the UKCA marking is applied to the product where applicable.
Indicates whether the EAC marking is applied to the product where applicable.
Indicates whether the product has a declared UL Listed certification or recognition status.
Indicates whether the product has a declared UL Recognized certification or recognition status.
Indicates whether the cULus mark is applied to the product where applicable.
Indicates whether the manufacturer declares product compliance with IEC 60529.
Indicates whether the manufacturer declares product compliance with IEC 62262.
Indicates whether the product has been tested according to applicable methods of the IEC 60068 series.
Indicates whether product compliance with applicable RoHS restrictions on hazardous substances has been declared.
Indicates whether the manufacturer declares compliance of the product with applicable REACH Regulation requirements.
Indicates whether the product falls within the scope of WEEE requirements for waste electrical and electronic equipment.
Compliance with IEC 60947-4-2 requirements applicable to semiconductor motor controllers, starters and soft-starters.
Compliance with the European adoption EN IEC 60947-4-2 applicable to semiconductor motor controllers, starters and soft-starters.
Compliance with UL 60947-4-2 requirements applicable to AC semiconductor motor controllers and starters.
Compliance with CSA C22.2 No. 60947-4-2 requirements applicable to semiconductor motor controllers and starters.