What Is a 3 Phase Servo Voltage Stabilizer?
A 3 phase servo voltage stabilizer is an electromechanical voltage regulation device designed for three-phase power systems. It detects input voltage variations and uses a servo motor to adjust an autotransformer, ensuring the output voltage remains stable—typically at 380V or a user-specified value. This is critical for CNC machines, which demand consistent and clean power to protect sensitive control systems and ensure machining precision.
Technical Parameters
| Model | SJW3-1.5KVA~120KVA | |||||
| Phase | Three phase | |||||
| Input voltage | AC 260-450V, 304-456V or customized | |||||
| Output voltage | AC 380V or customized | |||||
| Frequency | 50Hz/60Hz | |||||
| Precision | ±3% | |||||
| Efficiency | >95% | |||||
| Control type | Servo motor | |||||
| Digital display | Show input and output voltage,Load Ratio and Fault Indicator | |||||
| Protection | Overvoltage, Overload, Short circuit, Over temperature | |||||
| Ambient temperature | -10°C~+ 40°C | |||||
| Relative Humidity | <95% | |||||
| Waveform Distortion | No additional wave form distortion | |||||
| Insulating Resistance | Normally more than 2MΩ | |||||
| Insulating Class | Class B | |||||
| Protection | Overvoltage | Output Voltage ≥ 425V ± 4V | ||||
| Low voltage | Output Voltage ≤ 310V ± 4V | |||||
| Over temperature | 95℃±10℃ | |||||
| Delay protection | Customizable | |||||
| Undervoltage | Disabled by default, customizable if needed | |||||
| Power | 10KVA | 15KVA | 20KVA | 30KVA | 40KVA | |
| Size(mm) L*W*H | 490*320*520 | 490*320*520 | 490*320*520 | 410*460*880 | 410*460*880 | |
| N.W(kg) | 35.5 | 41 | 46.5 | 85.5 | 95.5 | |
| Power | 50KVA | 60KVA | 80KVA | 100KVA | 120KVA | |
| Size(mm) L*W*H | 450*550*1195 | 450*550*1195 | 520*620*1335 | 520*620*1335 | 520*620*1335 | |
| N.W(kg) | 121.5 | 136 | 158.5 | 186 | 198 | |
| The size and weight vary depending on the voltage range, and are subject to the customized actual product. | ||||||
Protection Thresholds:
- Overvoltage: ≥ 425V ± 4V
- Low Voltage: ≤ 310V ± 4V
- Over Temperature: 95℃ ± 10℃
- Delay / Undervoltage: Customizable
Why Choose SUNWAY Servo Voltage Stabilizers?
SUNWAY’s SJW3 Series stabilizers are developed for demanding industrial environments. Backed by certifications like ISO9001, CE, and IEC, and designed in compliance with global standards (including IEEE power quality guidelines), they deliver:
- High Accuracy: Voltage regulation within ±3%, maintaining CNC tool accuracy and reducing wear.
- Wide Input Range: From 260V to 450V (customizable), ideal for unstable grid areas.
- Real-Time Monitoring: Digital display shows input/output voltage, load ratio, and fault status.
- Full Protection Suite: Overvoltage, overload, overheating, short circuit, and optional delay/undervoltage protection.
- High Efficiency: >95%, with no waveform distortion, ensuring compatibility with inverter-based CNC systems.
What Makes Servo Voltage Stabilizers Ideal for CNC Machines?
Compared with static or relay-type stabilizers, servo voltage stabilizers offer the best balance between response speed, precision, and cost for motor-driven industrial loads. They are:
- More precise than relay stabilizers.
- More tolerant of high current fluctuations, ideal for inductive CNC motors.
- Durable in harsh working conditions, although they do have mechanical components (unlike static types, which use solid-state components).
Important clarification: While static stabilizers have no moving parts and thus lower mechanical wear, servo stabilizers are still preferred for high-capacity CNC equipment due to their robust load handling and proven long-term performance.
Selection Guide: How to Choose the Right Stabilizer for Your CNC Machine
To determine the right size stabilizer, consider the starting power, not just the rated power, of your CNC machine. In most cases:
✅ Recommended rule: Choose a stabilizer rated at 1.5 to 2 times your CNC machine’s rated power.
This ensures the stabilizer can handle inrush current, voltage drops, and other transient conditions during machine startup or heavy operations.
Example:
- If your CNC machine is rated at 10kVA, select a 15–20kVA stabilizer.
- For 25kVA machines, a 40–50kVA stabilizer is more suitable.
FAQs
Q1: What’s the main advantage of a servo stabilizer for CNC applications?
A: Servo stabilizers offer precise voltage correction with ±3% accuracy, which protects sensitive CNC controllers and prevents output quality defects caused by voltage fluctuation.
Q2: How do I know if I need a wider input voltage range?
A: If your facility experiences frequent voltage drops or surges beyond standard ranges (e.g., below 260V or above 450V), we recommend a customized input range. Our team can help you analyze your power conditions.
Q3: What’s the difference between servo and static stabilizers?
A: Servo stabilizers use a motorized mechanism to adjust voltage, making them better for high-load and dynamic applications like CNC machines. Static stabilizers use solid-state electronics—faster and quieter, but typically used for IT or medical equipment due to lower load handling capacity.
