150KVA Three-Phase Dry-Type Isolation Transformer 380V to 220V: Advantages in Machine Tool Control and Applications

A 150KVA three-phase dry-type isolation transformer plays a crucial role in industrial automation, especially for machine tool control systems. It not only provides reliable voltage conversion from 380V to 220V but also offers electrical isolation, safety protection, and interference suppression. This makes it an essential power device for CNC machines, precision grinding equipment, EDM machines, and other industrial tools requiring stable and interference-free control circuits.

1. Safety Isolation – The Primary Advantage

Electrical separation: The transformer provides magnetic coupling only between the 380V primary side and 220V secondary side, with no direct electrical connection. Even if a fault occurs, operators are protected from hazardous voltages, effectively reducing electric shock risks and complying with international safety standards (IEC, ANSI, GB).

Control system protection: It prevents high voltage from the 380V line from entering sensitive 220V circuits due to insulation failure. This protects critical components such as PLCs, servo drives, CNC controllers, touch screens, and relays from damage, ensuring system reliability.

2. Power Purification and Interference Suppression

Surge and spike suppression: Power surges from large equipment startup or lightning can cause failures. The transformer mitigates these surges, delivering a stable power supply to electronic controllers.

Common-mode noise elimination: It reduces harmonic interference from inverters and servo systems, ensuring stable encoder feedback, Ethernet, and Profibus communication, thereby minimizing machining errors.

Ground loop interruption: The isolation transformer breaks potential ground loops, preventing interference and ensuring accurate control signal transmission.

3. Voltage Stabilization

Although not a dedicated stabilizer, the transformer absorbs small grid fluctuations and provides the control circuits with a more stable voltage. This prevents unplanned equipment restarts and avoids damage caused by under-voltage or over-voltage conditions.

4. Advantages for Industrial Environments

Maintenance-free: With epoxy resin insulation, dry-type transformers require no oil checks, reducing maintenance costs compared to oil-immersed types.

Fire safety: No oil means no leakage risks, making it ideal for workshops with strict fire protection requirements.

Excellent cooling: Natural or forced air cooling ensures reliable long-term operation, even under heavy industrial loads.

5. Typical Application Cases

Case 1: CNC Lathes and Milling Machines
In a production workshop with multiple CNC machines, each requires 220V for its control circuits while the grid supplies 380V. By installing one isolation transformer per machine or group, power reliability improves. Distributed supply prevents one failure from halting the entire line, while interference from welding machines or cranes is effectively isolated.

Case 2: Precision Grinding and EDM Machines
These machines demand extremely stable signals. An isolation transformer powers the entire control system, including servo motors and EDM power units, improving resistance to electrical noise and ensuring high machining accuracy and surface finish quality.

6. Operating Conditions

The 150KVA  three-phase dry-type isolation transformer is designed for indoor environments and must meet the following conditions:

• Ambient temperature: -15℃ to +45℃
• Altitude: Below 1000m
• Relative humidity: Below 95%
• Free from explosive, corrosive, or conductive dust
• Installation site without severe vibration or impact

The 150KVA three-phase dry-type isolation transformer (380V to 220V) is a highly effective solution for enhancing safety, reducing interference, and protecting sensitive control systems in industrial machine tools. Its maintenance-free design, fire resistance, and robust performance make it ideal for demanding workshop environments. By ensuring electrical isolation, stable voltage, and reliable signal transmission, it minimizes downtime, improves machining accuracy, and extends equipment lifespan. When selecting a transformer, always ensure the specifications match the machine tool’s power requirements and installation conditions.