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QB-7 Series Low Voltage Soft Starter Side Side View
QB-7 Series Low Voltage Soft Starter Front View
QB-7 Series Low Voltage Soft Starter Side Side View
QB-7 Series Low Voltage Soft Starter Front View

QB-7 Series Low Voltage Soft Starter

ATA QB-7 series motor soft starters integrate power electronics and advanced motor control technology. They are an ideal replacement for traditional auto-transformer, star-delta and magnetic starters. With excellent soft starting performance, they are perfectly applicable to heavy-duty loads such as fans, pumps, compressors and ball mills. They effectively reduce starting impact, protect motors and mechanical equipment, and extend service life with stable and reliable operation.

Features

Optimized Structural Design

Dual CPU structure with mutual redundancy for reliable operation,proprietary compact internal design for easy integration into existing systems.

The built-in bypass functionality eliminates the need for external accessories, saving costs and reducing space requirement.

Extensive User Interfaces

Standard 485 communication, PROFIBUS communication is optional, 1 fault output (passive), 2 programmable relay output (passive), 2 programmable logic input (active), 1 programmable logic output (active), users can configure according to needs.

High Scalability

Expandable function(The built-in bypass mode is unavailable): You can choose the Internet real-time monitoring module or leakage detection module extension according to your needs. (Both are optional accessories,And you can only choose one of two).

Diverse Start-stop Modes

ATA QB-7 series features four starting modes: voltage start, ramp start, current-limit start, and heavy-load (kick start) start.

Advanced Event Logging

Dynamic fault log stores 80+ records, enabling quick troubleshooting.Automatic updating saves storage space.

Flexible Wiring Options

Suitable for electric motor internal and external wiring mode.

Comprehensive Protection

Over current, motor overload, current three-phase unbalance, over/under-voltage, phase loss, overheating, under-load, PTC and thyristor short circuit and other protection functions.

Multi-Protocol Communication

The built-in communication port allows direct communication with the PC for remote control and telematics. (RS-485 interface as standard, Porfibus interface is optional).

Enhanced Display Capabilities

LCD display in line with a variety of working conditions, language support Chinese and English switching, support expandable display, convenient for complete sets of cabinets.

Technical Specifications

Voltage rangeAC380V-AC1140V
Current range16A-1600A
Typical power rangeUp to 800kW
Starting current limit200%-500% of rated current, adjustable
Starting modesVoltage start / Ramp start / Current-limit start / Kick start
Stop modesFree stop / Soft stop
Protection functionsOver-current, motor overload, current three-phase unbalance, over/under-voltage, phase loss, overheating, under-load, PTC and thyristor short circuit and other protection functions.
Communication interfacesStandard 485 communication, PROFIBUS communication is optional
Operating temperature-10 to +40 degrees C
AltitudeUp to 2000m standard, higher on request
Enclosure protection classIP20 standard / IP54 for cabinet version
Certifications for this specific modelCE: CN25QSYC 001, CCC: 2024010304706152
Cabinet dimensions for 7.5kW-250kW600*800*2200
Cabinet dimensions for 320kW-800kW800*800*2200

Applications

Equipment types this model is suitable forFans / Pumps / Compressors / Conveyors / Ball Mills / Crushers / Mixers / Blowers
PetrochemicalPump starts on refinery sites
Steel and MetalStarting large rolling mill drive motors
MiningCompressor starts in underground environments

Technical Documents

ATA QB-7 Selection Manual
PDF

FAQ for QB-7 Series Low Voltage Soft Starter

Does the QB-7 series have built-in bypass contactor?

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Yes, QB-7 models integrate a built-in bypass contactor, reducing on-site wiring complexity and minimizing heat loss during continuous operation.

Can QB-7 be used with heavy-duty loads like ball mills or crushers?

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Yes, QB-7 supports heavy-duty starting with adjustable initial voltage and ramp-up time, ideal for ball mills, crushers, and other high-inertia loads.

Can QB-7 prevent water hammer in pump applications?

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Yes, QB-7 includes a soft stop function with adjustable ramp-down time, which effectively reduces water hammer and pipe pressure shocks in centrifugal pump systems.

Can QB-7 be used with different voltage standards (380V / 400V / 415V)?

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Yes, QB-7 is designed for a wide input voltage range (380–1140V AC, 50/60Hz), suitable for most global low-voltage power grids.

Related products

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