Qoltec 20kVA Three-Phase Servomotor Voltage Stabilizer AVR with LCD, ±3% Accuracy, Expert Line

Where most stabilizers react slowly or drift under uneven phase loads, the Qoltec 51908 holds all three phases to ±3% output accuracy using a servomotor-driven autotransformer. Built for workshops, server rooms, and industrial lines, this 20kVA floor-standing unit accepts a wide 260–430V AC input and delivers a stable 380V AC output at 50/60Hz, with overload, over/undervoltage, short-circuit, and overheat protection as standard.

Highlights

• True three-phase stabilization with servomotor control and <1.5s response for 10% input change
• LCD panel for real-time input/output voltage, load, and fault status
• Efficiency above 95% and THD below 1% keep downstream equipment clean and cool
• IP20 enclosure, insulation class F, operating range -10°C to +40°C, up to 90% non-condensing humidity
• Floor-standing design with robust terminals for permanent installation

In daily use

Connect the 51908 between your main supply and sensitive machinery, CNC controllers, or IT racks. The servomotor continuously adjusts the transformer taps to compensate for grid fluctuations, brownouts, and phase imbalance. The LCD gives at-a-glance confirmation that all three phases remain within the ±3% window, while the built-in protections disconnect the load before damage can occur. No software, no network configuration—just hardwired reliability.

Full specifications

• Power capacity: 20 kVA
• Phase: Three-phase
• Input voltage range: 260V ~ 430V AC
• Output voltage: 380V AC
• Output voltage accuracy: ±3%
• Frequency: 50 Hz / 60 Hz
• Stabilization technology: Servomotor
• Display type: LCD
• Response time: < 1.5 seconds (for 10% change)
• Efficiency: > 95%
• Protection features: Overload, Overvoltage, Undervoltage, Short Circuit, Overheat
• Operating temperature: -10°C ~ +40°C
• Operating humidity: 0 ~ 90% (non-condensing)
• Total Harmonic Distortion (THD): < 1%
• Insulation class: F
• IP rating: IP20
• Enclosure type: Floor-standing

Final note

For three-phase environments where voltage drift is not an option, the Qoltec Expert Line 51908 delivers servomotor precision in a rugged, no-nonsense package.