In heavy-industry, mining, and utility environments, voltage stabilizers are subjected to continuous high loads, harsh ambient conditions, and severe voltage fluctuations. Dry-type or air-cooled stabilizers often reach their thermal limits under such conditions, leading to derating, premature failure, or costly downtime.

Our oil-immersed voltage stabilizer solves this challenge by immersing the auto-transformer and regulation mechanism in high-grade mineral insulating oil, which provides:

Superior heat dissipation – Oil conducts heat away from windings far more efficiently than air, allowing continuous full-load operation even in high ambient temperatures.

Enhanced overload capability – The thermal mass of the oil absorbs short-term overloads without immediate temperature rise.

Extended service life – Oil protects windings from moisture and oxidation, preserving insulation integrity for 25+ years.

Outdoor suitability – Sealed tank construction with radiators allows direct outdoor installation without additional enclosures.

Lower noise – Oil acts as a sound-dampening medium, reducing operational noise compared to equivalent air-cooled units.

High Capacity Range – 200 kVA to 5000 kVA standard; larger capacities available for special projects.

Precision Regulation – Output accuracy ±1% to ±3%, ensuring stable operation of heavy industrial loads.

Wide Input Voltage Range – Typically ±15% to ±25% of nominal; extended ranges available for unstable grids.

Heavy Overload Capability – 120% continuous, 150% for 30 min, 200% for 1 min (typical, oil-cooled thermal headroom).

Fast Response – Servo correction time ≤ 1–3 seconds.

High Efficiency – ≥ 95% to 98%, minimizing energy losses and operating costs.

Three-Phase Independent Regulation – Each phase corrected independently, maintaining balance under unbalanced loads.

Comprehensive Protection

Over-voltage protection (OVP)

Under-voltage protection (UVP)

Over-current / overload protection (OCP)

Short-circuit protection (SCP)

Over-temperature protection (OTP)

Buchholz relay (gas detection) for internal faults

Pressure relief valve

Oil level monitoring

Phase loss / phase sequence protection (control circuit)

Outdoor Rated – IP23 (standard) or IP54 (optional) tank; anti-corrosion paint; suitable for direct outdoor installation.

Intelligent Monitoring – Digital display (voltage, current, oil temp.); optional RS485 / Modbus / SNMP remote monitoring.

Low Noise – ≤ 65–70 dB depending on kVA; oil damping reduces mechanical noise.

Continuous Duty – Designed for 24/7 operation in ambient temperatures from –25 °C to +45 °C (special designs for extreme climates available).

Packing: Export-grade wooden crate or steel skid, moisture-proof wrapping, VCI anti-corrosion protection. Oil may be shipped filled or separately depending on transport regulations.

Transport: Suitable for 20 ft / 40 ft container, flat-rack, or break-bulk depending on unit size and quantity.

Delivery Time: Typically  7 days after order confirmation and drawing approval (adjust to your actual lead time).

Incoterms: EXW / FOB / CIF / DDP – flexible terms available.

Documentation: Commercial invoice, packing list, Bill of Lading, Certificate of Origin, factory test report, oil test report, CE certificate.