Correct Model Selection for Your Project
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Verify that this model matches your voltage, current, and load type.
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Unsure which model is suitable? Our engineering team will confirm the correct model before shipment.
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Need custom solutions or a fast project quote? Contact us – we respond within 12 hours.
Contact Us
Email: ann@softstarterpro.com
💬 WhatsApp: +8618006697926
Project & Ordering FAQs
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What info is needed for a project quote?
Motor type, voltage, current/power, application, quantity, environment. -
Can I order a single unit for testing?
Yes, sample orders available for engineering evaluation. -
Do you support custom solutions?
Yes, OEM/ODM and custom control options available. -
Lead time & delivery?
Standard: 3-5 working days. Custom: depends on requirements. -
Technical support & documentation?
Pre-sales and after-sales support, manuals, diagrams, and wiring guidance provided.
Поделение
Specification
- Model: RQ900-37KW 380V
- Current: 74A
- Voltage: 380V
- Dimension: 272*146*160MM
- Gross Weight: 4KG
Product Description
The Aigoodele LSRQ900 series is a versatile three-phase motor soft starter engineered for 50HP (37kW) AC motors operating on 380V-420V industrial power systems. With wide voltage compatibility and advanced control features, it provides reliable motor protection and smooth startup performance.
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Wide Voltage Compatibility: Suitable for 380V, 400V, and 420V three-phase systems
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High Current Rating: 74A capacity for 50HP motor applications
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Advanced Communication: RS485 interface for system integration
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Comprehensive Protection: Reduces inrush current and mechanical stress
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Energy-Saving Design: Bypass operation after startup completion
Applications
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Industrial pump and compressor systems
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HVAC and ventilation equipment
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Conveyor and material handling systems
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Machinery in regions with 380V-420V power standards
Note
This soft starter requires professional installation and proper configuration. Ensure voltage settings match your local power supply specifications for optimal performance.
Advanced Specifications
| Parameter | Specification |
| Starter Type | Bypass Type |
| Starting Method | Current Limiting / Voltage Ramp / Surge Voltage Ramp |
| Stop Method | Free Stop / Soft Stop |
| Current Limit Range | 50% ~ 600% adjustable |
| Voltage Ramp Time | 1s ~ 120s adjustable |
| Soft Stop Time | 1s ~ 60s adjustable |
| Cooling Method | Natural Cooling |
| Communication | RS485 Modbus RTU |
| Protection Class | IP20 |
| Ambient Temperature | -25°C ~ +40°C |
| Installation | Wall-mounted |
Comprehensive Motor Protection Functions
| Protection | Description |
| Overload | Adjustable grade 0–30, startup & running |
| Over/Under Voltage | Trips at abnormal supply voltage |
| Phase Loss | Input & output phase loss detection |
| Phase Imbalance | Adjustable threshold, auto shutdown |
| Underload | Prevents pump dry-running & cavitation |
| Overtemperature | Internal thermal monitoring |
| SCR Fault | Thyristor breakdown detection |
| Fault Memory | Last 12 fault records stored |
Frequently Asked Questions
Q: What is the difference between bypass type and online type? Which should I choose?
A: Bypass type switches to a bypass contactor after startup, eliminating SCR heat loss — lower energy consumption and easier wiring. Online type keeps the SCR active during running. We recommend bypass type for most applications, especially if you want simpler installation and lower running costs.
Q: How do I select the right soft starter size for my motor?
A: General rule:
- Heavy-duty loads (compressors, conveyors): choose 2 sizes up from motor rating
- Light-duty loads (fans, pumps): choose 1 size up or match motor rating
👉 For detailed selection guidance, refer to our soft-starter-selection-guide
Q: Can a soft starter control motor speed?
A: No. A soft starter only controls startup and stop — it cannot vary speed during running. If you need variable speed control, please choose a VFD (Variable Frequency Drive) instead.
Q: Is it compatible with synchronous motors?
A: No. This soft starter is designed for squirrel cage induction motors (asynchronous) only. It is not compatible with synchronous motors or wound rotor (slip ring) motors.
📄 Download Manual LSRQ900 Series Soft Starter Manual
