- Type: furnace / ladle refining / rectifier
- Custom capacity & voltage per duty
- Reinforced winding & cooling
- Standard: IEC 60076
Our power-frequency furnace transformers are engineered to deliver the high secondary current required by electric arc furnaces (EAF), ladle refining furnaces (LRF), and induction heating systems. Built for frequent overload and short-circuit duty, these transformers feature reinforced windings and advanced cooling systems to ensure reliable performance in the most demanding industrial environments.
Key Features
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High Secondary Current Output – Designed to supply the massive current demands of electric arc furnaces, ladle refining furnaces, and induction heating applications.
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Reinforced Windings – Mechanically strengthened to withstand repeated thermal cycling, electromagnetic forces, and short-circuit stresses.
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Frequent Overload Capability – Engineered for the cyclic loading profiles typical of steelmaking and foundry operations.
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Short-Circuit Duty Rated – Built to endure the high-magnitude fault currents associated with arc furnace operation.
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Advanced Cooling Systems – Available in oil-immersed (ONAN/OFWF) and water-cooled configurations to manage high thermal loads.
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Custom Voltage & Impedance Design – Tailored to match furnace characteristics, electrode control systems, and plant power distribution.
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Robust Tank & Core Construction – Heavy-gauge steel tanks, step-lap core construction, and vibration-dampening mounts for long service life.
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Comprehensive Protection & Monitoring – Optional dissolved gas analysis (DGA), fiber-optic temperature sensing, and online partial discharge monitoring.
Technical Specifications (Typical Range)
| Parameter | Typical Range |
|---|---|
| Rated Capacity | 5 MVA – 120 MVA |
| Primary Voltage | 13.8 kV – 138 kV |
| Secondary Voltage | 100 V – 1,500 V |
| Secondary Current | Up to 80,000 A |
| Frequency | 50 Hz / 60 Hz |
| Cooling Type | ONAN, ONAF, OFWF, OFAF |
| Impedance | 4% – 12% (customizable) |
| Tap Changer | On-load tap changer (OLTC) or off-circuit |
| Insulation Class | Class F / Class H |
| Standards | IEEE C57.12.00, IEC 60076, ANSI, NEMA |
Applications
1. Electric Arc Furnaces (EAF)
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Steel scrap melting and refining
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High cyclic loading with frequent short circuits
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Requires low-impedance, high-current secondary design
2. Ladle Refining Furnaces (LRF)
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Secondary metallurgy and temperature control
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Stable arc operation with precise voltage regulation
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Argon stirring and alloy addition support
3. Induction Heating Systems
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Billet and slab heating
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Forging and heat treatment
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Melting in foundries
Design & Construction Highlights
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Core: High-grade grain-oriented silicon steel, step-lap mitered joints for low loss and noise.
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Windings: Copper or aluminum, double-layer disc or continuous disc type, reinforced with epoxy-bonded insulation.
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Tank: Welded steel construction with stiffeners, pressure-tested for oil-immersed units.
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Cooling: Radiator banks, forced-air fans, oil pumps, or water-cooled heat exchangers.
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Bushings: High-current, low-voltage secondary bushings with flexible connections.
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Tap Changer: Motor-driven OLTC with remote control and auto/manual modes.
Frequently Asked Questions (FAQ)
Q1: What makes a power-frequency furnace transformer different from a standard distribution transformer?
A: Furnace transformers are designed for much higher secondary currents, frequent overloads, and repeated short-circuit events. They use reinforced windings, specialized cooling, and low-impedance designs to handle the harsh duty cycle of arc furnaces and induction heating.
Q2: Can your transformers be customized for my specific furnace?
A: Yes. We custom-design each unit based on your furnace type, power rating, voltage levels, impedance requirements, cooling method, and plant layout. Please provide your process parameters for a tailored solution.
Q3: What cooling methods are available?
A: We offer ONAN (oil natural air natural), ONAF (oil natural air forced), OFWF (oil forced water forced), and OFAF (oil forced air forced) cooling. The choice depends on your power rating, ambient conditions, and installation environment.
Q4: How do you ensure reliability under frequent short-circuit conditions?
A: We use mechanically reinforced windings, high-strength insulation systems, and rigorous short-circuit testing per IEEE/IEC standards. Our designs are validated through thermal, dielectric, and mechanical type tests.
Q5: What maintenance is required?
A: Routine maintenance includes oil testing (DGA, moisture, dielectric strength), cooling system inspection, tap changer servicing, and visual checks for leaks or corrosion. We provide detailed O&M manuals and remote monitoring options.
Q6: Do you provide after-sales support and spare parts?
A: Yes. We offer installation supervision, commissioning, training, spare parts, and 24/7 technical support. Extended warranties and preventive maintenance contracts are available.
Q7: What standards do your transformers comply with?
A: Our transformers are designed and tested to IEEE C57.12.00, IEC 60076, ANSI, and NEMA standards. We can also meet local utility and industry-specific requirements.
Q8: What is the typical lead time?
A: Lead time varies by rating and customization. Standard units typically ship in 12–20 weeks; highly customized or large units may require 20–30 weeks. Please contact us for a specific schedule.
