Oil Cooled Servo Stabilizer
150kVA – 2000kVA | 3-Phase | Oil Immersed Cooling
VoltaPex oil cooled servo stabilizer is designed for extreme industrial environments – steel plants, cement factories, chemical plants, and outdoor installations. Superior heat dissipation, dust protection, and 200% overload capacity.
What is an Oil Cooled Servo Stabilizer?
For industrial applications above 150kVA, air cooling becomes insufficient. An oil cooled servo stabilizer uses transformer oil as both an insulating and cooling medium, allowing much higher power densities and protection against dust, moisture, and corrosive atmospheres.
Superior Heat Dissipation
Oil has much higher thermal conductivity than air, allowing continuous operation at 100% load even in ambient temperatures up to 55°C.
Dust & Moisture Protection
Sealed oil tank construction keeps out dust, salt spray, and humidity – perfect for cement plants and outdoor installations.
Copper Wound Construction
100% electrolytic copper windings – lower losses, better heat transfer, and 25+ year lifespan.
Quieter Operation
Oil dampens magnetic hum from the variac – significantly quieter than air-cooled units.
Oil Cooled vs Air Cooled – Which One Do You Need?
Oil Cooled Servo Stabilizer
- Superior heat dissipation – handles 55°C ambient
- Sealed construction – dust and moisture proof (IP54/IP65)
- Lower operating temperature – longer insulation life
- Suitable for outdoor installation
- Quieter operation (oil dampens magnetic hum)
- Recommended for capacities >150kVA
- Longer lifespan (20-25 years)
Air Cooled Servo Stabilizer
- Limited to 40°C ambient temperature
- Dust accumulation requires regular cleaning
- Louder operation (fan noise)
- Not suitable for outdoor or dusty environments
- Higher operating temperature
- Recommended only up to 150kVA
- Shorter lifespan in harsh environments
Oil Immersed Servo Stabilizer Construction
An oil immersed servo stabilizer consists of a copper-wound variac, servo motor, and control components all enclosed in a mild steel tank filled with high-grade transformer oil (IS 335).
Key Features
- CRGO silicon steel core for minimum losses
- 100% copper wound (no aluminium)
- Heavy-duty servo motor with silver-graphite brushes
- IP54 to IP65 enclosure (tank + terminal box)
- Oil level gauge, drain valve, filling plug, temperature indicator
- Optional silica gel breather prevents moisture ingress
Oil Cooled vs Air Cooled – Efficiency Comparison
Oil cooled stabilizers maintain 98% efficiency even at 55°C ambient. Air cooled units derate significantly above 40°C – losing 1-2% efficiency for every 5°C rise.
| Capacity Range | 150kVA – 2000kVA |
| Input Voltage (3-Phase) | 240V – 490V (Line to Line) |
| Output Voltage | 415V ±1% (Adjustable) |
| Oil Type | IS 335 Transformer Oil |
| Temperature Rise | <45°C above ambient |
| Overload Capacity | 200% for 10 sec / 150% for 60 sec |
| Enclosure Protection | IP54 (Standard) / IP65 (Optional) |
| Insulation Class | Class H (180°C) |
| Ambient Temperature | -10°C to 55°C |
| Standards | IS 9815, IEC 60076, CE |
Popular Oil Cooled Stabilizer Capacities
For heavy industrial applications above 150kVA
| kVA Rating | Typical Application | Input Range | Dimensions (L×W×H mm) | Approx. Price (INR) |
|---|---|---|---|---|
| 150 kVA | Large workshop / Textile mill | 260-480V | 1300×900×1500 | ₹2,50,000 – ₹3,20,000 |
| 200 kVA | Cement plant crusher / Large compressor | 260-480V | 1400×1000×1600 | ₹3,50,000 – ₹4,50,000 |
| 250 kVA | Plastic injection moulding plant | 260-480V | 1500×1000×1700 | ₹4,50,000 – ₹5,80,000 |
| 300 kVA | Steel rolling mill / Chemical plant | 250-480V | 1600×1100×1800 | ₹5,00,000 – ₹6,50,000 |
| 400 kVA | Mid-size manufacturing plant | 250-480V | 1700×1200×1900 | ₹6,50,000 – ₹8,50,000 |
| 500 kVA | Large factory / Industrial estate mainline | 250-480V | 1800×1300×2000 | ₹8,00,000 – ₹11,00,000 |
| 750 kVA | Large manufacturing facility | 240-480V | 2000×1500×2200 | ₹12,00,000 – ₹16,00,000 |
| 1000 kVA | Heavy industrial plant / Steel mill | 240-480V | 2200×1600×2400 | ₹15,00,000 – ₹22,00,000 |
| 1500-2000 kVA | Large cement factory / Industrial township | 240-480V | Custom | On Request |
Where Oil Cooled Stabilizers Are Used
Steel Plants
Rolling mills, furnaces
Cement Factories
Crushers, conveyors, kilns
Chemical Plants
Reactors, mixers, pumps
Power Plants
Auxiliary systems
Water Treatment
Large pumps, aeration
Textile Mills
Spinning, processing
Paper Mills
Pulpers, dryers, winders
Data Centers
Mainline protection
Oil Cooled Servo Stabilizer – Complete Guide for Heavy Industries
For heavy industrial applications above 150kVA, an oil cooled servo stabilizer is the only reliable choice. Unlike air-cooled units, oil immersed design provides superior heat dissipation, dust protection, and longevity in harsh environments.
Why Oil Cooling is Essential for Heavy Industries
Industries like steel plants, cement factories, and chemical processing units have extreme operating conditions:
- Ambient temperatures often exceed 50°C near furnaces and kilns
- Dust and particulate matter clog air-cooled units within weeks
- Continuous 24×7 operation leaves no downtime for cleaning
- Large motors (hundreds of HP) create massive heat loads
An oil immersed servo stabilizer solves all these problems with sealed construction and superior thermal management.
Maintenance of Oil Cooled Stabilizers
Oil cooled industrial servo stabilizers require minimal maintenance:
- Check oil level every 6 months; top up with same grade oil if needed
- Test oil dielectric strength every 2 years; replace if below 25 kV
- Inspect carbon brushes on the variac every year; replace when worn below 50%
- Check for oil leaks around gaskets and bushings
Oil Cooled vs Air Cooled – Total Cost of Ownership
While oil cooled stabilizers have higher initial cost, they offer lower total cost of ownership over 20+ years due to higher efficiency, longer lifespan, and minimal maintenance. Air cooled units in harsh environments may need replacement every 5-7 years.
VoltaPex is a leading industrial stabilizer manufacturer of oil cooled servo stabilizers, serving industries across India for over 15 years. All units feature copper wound stabilizer construction and are type tested as per IS 9815.
Frequently Asked Questions
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