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Online Soft Starter PQZR8-SZ220-T4 | Single Phase & Three Phase Motor Soft Starter with Built-in Bypass
Product Overview
The PQUAN PQZR8-SZ220-T4 Online Soft Starter is an intelligent motor control device that combines soft-start, soft-stop, and full-speed bypass operation in a single compact unit. Designed for both single-phase and three-phase AC motors, this versatile motor soft starter gradually ramps up voltage during startup, eliminating the damaging inrush current and mechanical shock associated with direct-on-line (DOL) starting.
Unlike conventional soft starters that require an external bypass contactor, the online integrated soft starter features a built-in bypass mechanism. Once the motor reaches full speed, the internal bypass contactor engages, routing current through the bypass circuit and reducing heat generation in the thyristors (SCRs). This "online" design means the unit remains connected and continues to monitor motor current and protect the system during normal operation, providing the best of both worlds: smooth starting and energy-efficient continuous running.
With a user-friendly detachable LCD panel that can be extended via network cable for remote mounting, the PQZR8 series offers flexible installation in control cabinets, machine rooms, and industrial environments where the main unit may be located away from the operator. The real-time display shows line voltage, phase currents (IA, IB, IC), and operating status, keeping operators fully informed at a glance.
Key Performance Advantages
Smooth Soft Start & Soft Stop
The core function of the intelligent soft starter is to control motor acceleration and deceleration through gradual voltage ramp-up. By limiting starting current to typically 2–3 times the rated current (versus 5–7 times with DOL starting), it reduces stress on motor windings, bearings, belts, gears, and coupled mechanical equipment. Soft-stop functionality similarly prevents water hammer in pumping systems and coasting damage in high-inertia loads like fans and centrifuges.
Built-in Bypass for Energy Efficiency
After the soft-start process completes, the internal bypass contactor automatically closes, allowing full current to flow through the contactor rather than the SCR modules. This eliminates standby heat loss from the thyristors, significantly improving energy efficiency and extending the service life of power components. The online soft starter with bypass maintains full monitoring and protection capabilities while running in bypass mode.
Comprehensive Motor Protection
The PQZR8 soft starter incorporates multiple layers of protection to safeguard your motor and investment: overload protection (adjustable Class 10/20), overcurrent protection, phase loss protection, phase imbalance detection, overvoltage and undervoltage protection, over-temperature protection, and short-circuit protection. In the event of a fault, the unit trips immediately and displays an error code on the LCD, enabling rapid diagnosis and minimizing downtime.
Detachable Remote Operation Panel
The front control panel is fully detachable and can be mounted remotely using a standard network cable (RJ45 extension), effectively suppressing electromagnetic interference. This is particularly valuable when the soft starter is installed inside a sealed electrical cabinet or in a high-vibration environment, while the operator needs to monitor and control from a convenient external location. The panel supports parameter setting, start/stop control, fault reset, and real-time data viewing.
Wide Voltage & Phase Compatibility
The PQZR8-SZ220-T4 supports both single-phase and three-phase motor configurations, with voltage compatibility covering 220V, 380V, and 440V industrial power standards. This dual-phase versatility makes it an ideal choice for exporters, OEMs, and system integrators who need a single product platform to serve diverse global markets, from small single-phase pump motors to larger three-phase compressor and conveyor drives.
Technical Specifications
Parameter |
Specification |
Model |
PQZR8-SZ220-T4 (Online Integrated Series) |
Motor Type |
Single-Phase / Three-Phase AC Asynchronous Motor |
Input Voltage |
220V / 380V / 440V AC (50/60Hz) |
Control Mode |
Soft Start / Soft Stop / Bypass Online Operation |
Starting Current |
2–3 × Rated Current (Adjustable) |
Start Time |
0–60s (Adjustable) |
Stop Time |
0–60s (Adjustable) |
Protection |
Overload, Overcurrent, Phase Loss, Phase Imbalance, Over/Under Voltage, Over-temperature, Short Circuit |
Display |
Detachable LCD with Real-time Voltage & Current |
Remote Panel |
Network Cable Extension (RJ45) |
Bypass |
Built-in Internal Bypass Contactor |
Cooling |
Natural Convection / Forced Air |
Ambient Temperature |
-10°C ~ 40°C |
Altitude |
≤1000m (derated above 1000m) |
Application Scenarios
The 3 phase soft starter is suitable for a broad range of industrial and commercial motor control applications:
- Water Pumps & Pumping Stations: Soft start prevents water hammer and pressure surges in centrifugal pumps, submersible pumps, and booster pump systems.
- Air Compressors: Reduces starting current and mechanical stress on screw compressors, piston compressors, and blower systems.
- Fans & Blowers: Smooth acceleration protects belts and bearings in HVAC fans, exhaust fans, and industrial blowers.
- Conveyors & Material Handling: Prevents belt slippage and product spillage on belt conveyors, bucket elevators, and screw conveyors.
- Mixers & Agitators: Controlled startup avoids sudden torque spikes in chemical mixers, food processing agitators, and wastewater aerators.
- Crushers & Grinders: Soft start reduces gearbox shock in stone crushers, hammer mills, and grinding machines.
Why Choose PQUAN?
Zhejiang PQUAN Technology Co., Ltd. is a professional manufacturer specializing in the R&D, production, and global distribution of motor control and power protection products. Our product portfolio includes intelligent soft starters, variable frequency drives (VFDs), and automatic voltage regulators, trusted by customers across Africa, the Middle East, Southeast Asia, Europe, and the Americas.
As a direct factory, we offer competitive wholesale pricing, flexible OEM/ODM customization (logo, labels, manuals, and enclosure specifications), and comprehensive technical support from product selection to after-sales service. Every soft starter undergoes rigorous pre-shipment testing, including full-load burn-in and protection function verification, and our products carry international certifications including CE and RoHS. We also provide 24/7 technical support, warranty coverage, readily available spare parts, and user training to ensure long-term customer satisfaction.
Whether you are a pump manufacturer, compressor OEM, system integrator, distributor, or end-user, the PQUAN PQZR8 online soft starter delivers the smooth starting, reliable protection, and energy efficiency your motor control system demands. Contact us today for a customized solution and competitive quotation.
FAQ
Q1:What's The Advantages Of Your Products? A1:We are a factory,so we have a number of production lines and first-class equipment and machines which means we have hundreds of specifications. And also the company has the right to import and export, first-class quality,excellent service and praise,by domestic and foreign customers. Q2:What Can I Buy From Your Company? A2:Variable Frequency Drive,Intelligent Soft Starter,Automatic Voltage Regulator. Q3:Is OEM/ODM Available? A3:Yes, it is! Our products can be customized. We design and produce all kinds of Automatic Voltage Regulators/Stabilizers according to our customers' specific requirements.Please notify us and confirm the design according tooursamples first. Q4:What Is The MOQ? A4:For the small capacity products (Automatic Voltage Regulators/Stabilizers)of the default configuration,it is 10 sets.For the big capacity products,it is 1 set.Please let us know which capacity do you need first. Q5:Can You Give Me A Sample Order First? A5:Yes,we welcome the sample orders to test and check the quality.Mixing samples is also acceptable Q6:How Can You Guarantee The Quality? A6:Always a pre-production sample before mass production; and always final inspection before shipment. |
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