Power Transformers
Up to 300 MVA | Up to 345 kV | India: IS 2026 / IEC 60076 | US/Export: IEEE C57.12.10
Up to 300 MVA | Up to 345 kV | India: IS 2026 / IEC 60076 | US/Export: IEEE C57.12.10
Marsons manufactures power transformers from medium voltage substations through to Extra-High Voltage transmission class units — serving India's 220 kV and 400 kV grid, and US transmission networks from 69 kV through 345 kV. We are the only EHV transformer manufacturer in Eastern India, with nearly 200 EHV units commissioned across the country's most demanding grid projects.
| Parameter | Value / Description |
|---|---|
| Rating (full range) | Up to 20 MVA (MV) | Up to 100 MVA (HV) | Up to 200 MVA 220 kV (India EHV) | Up to 300 MVA 345 kV (US/Export) |
| Voltage Classes — India | Up to 66 kV (MV) | Up to 132 kV (HV) | Up to 220 kV (EHV) | 400 kV planned |
| Voltage Classes — US | 69 / 115 / 138 / 230 / 345 kV |
| Frequency | 50 Hz (India) | 60 Hz (US) | 50/60 Hz available |
| Standards — India | IS 2026, IEC 60076 Parts 1–5 |
| Standards — US | IEEE C57.12.00, C57.12.10, C57.116, NERC/FERC |
| Insulating Fluid | PCB-free Mineral Oil per IS 335 / IEC 60296 / ASTM D3487. FR3 biodegradable on request. |
| Vector Group | YNyn0, YNd11, Dyn11 and others as required |
| Tap Changer | OLTC (Reinhausen MR standard; Cooper/Eaton for US service network) or OCTC |
| Cooling | ONAN / ONAF / OFAF / ODAF — all stages factory tested |
| Core Design | CRGO silicon steel, stepped-lap mitered construction. Hi-B GOES for US duty. |
| Winding Design | Interleaved disc windings (HV) for optimised impulse voltage distribution. CTC for LV windings. Intershield design for EHV. |
| Temperature Rise | Oil: 50°C | Winding: 55°C (IEC) | 65°C rise (IEEE) |
| Short-Circuit Strength | Designed per IEC 60076-5 / IEEE C57.12.00. Short-circuit test capability in-house. |
| Auxiliary Fittings | Buchholz relay, WTI, OTI, sudden pressure relay, PRD, online DGA port, fiber optic hot-spot monitoring |
From standard distribution to specialized power transformers, explore our robust, precision-engineered solutions designed to meet your exact energy infrastructure requirements.
A quality policy is a reflection of the endeavors and aims of the organization. Quality has always been a benchmark at Marsons.
Our uncompromising stance on quality and strict adherence to ISO 9001:2008 standards furnish our customers with the very best and reliable products.
To maintain these rigorous standards, our quality control activities are seamlessly integrated into every stage of the production cycle.
These core activities can be summarized as: custom order management, a strict approval system for all vendors, uncompromising manufacturing supervision, and comprehensive testing and inspection.
Our testing departments, utilizing high-end equipment, play a decisive role in the implementation of our quality program. We operate two laboratories, both equipped with modern machinery and precision instruments.
To ensure the highest accuracy, tests are conducted separately. One laboratory is strictly allotted for high/medium voltage transformers, and the other for medium/low voltage transformers.
Our quality is backed by accredited infrastructure. Our fully equipped NABL accredited laboratory can efficiently carry out all required routine and type tests, including Impulse lightning tests and Temperature rise tests.
This facility allows us to rigorously test various ratings of Power Transformers up to the range of 200 MVA 220 kV class using various conventional, state-of-the-art, and modern equipment.
Ready to power your infrastructure? Contact our experts today to discuss our wide range of ISO-certified distribution and power transformers, backed by 65 years of industry trust and credibility.
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