US Market Transformers
Up to 300 MVA / 345 kV | IEEE C57 Series | ANSI / DOE / NERC / FERC Compliant
Up to 300 MVA / 345 kV | IEEE C57 Series | ANSI / DOE / NERC / FERC Compliant
Marsons manufactures liquid-filled power transformers for the US grid — pad-mounted distribution, substation power, generator step-up (GSU), and specialty transformers — engineered to IEEE/ANSI standards with PE-stamped documentation for all 50 states. Our US portfolio covers voltages from 15 kV through 345 kV and ratings from 10 kVA to 300 MVA.
India's electrified railway network runs at 25 kV AC, 50 Hz from the overhead catenary. The locomotive transformer steps this down to 1,269 V to supply the three-phase regenerative drive system, which controls the traction motors. When the locomotive brakes, the drive returns electrical energy back through the transformer to the overhead line recovering energy that would otherwise be wasted as heat.
| Parameter | Value / Description |
|---|---|
| kVA Range | 10 kVA to 10,000 kVA |
| Voltage Classes | 15 kV Class | 25 kV Class | 35 kV Class |
| Primary Voltages | 4,160 V – 34,500 V |
| Secondary Voltages | 208Y/120 V | 480Y/277 V |
| BIL (Primary) | 95 kV (15 kV class) | 125 kV (25 kV) | 200 kV (35 kV) |
| Single-Phase Range | 10–167 kVA per IEEE C57.12.25 |
| Three-Phase Loop-Feed | 75–2,500 kVA per IEEE C57.12.34 |
| Three-Phase Radial | 75–10,000 kVA per IEEE C57.12.00 |
| Key US Features | Dead-front loop, 2 or 4 cable positions | 200A or 600A loadbreak elbow (LBOR/NCOR) | CSP design | FR3 biodegradable fluid | NEMA 3R tamper-resistant enclosure | Grounding per NESC | Seismic per IEEE 693 on request |
| Efficiency | DOE 2016 (10 CFR 431) compliant |
| Standard | IEEE C57.12.34 (3-phase) | IEEE C57.12.25 (1-phase) |
5 – 300 MVA
69 – 345 kV
IEEE C57.12.00/10
10 – 300 MVA
115 – 345 kV
IEEE C57.12.10
30 – 300 MVA
345/230/13.8 kV
IEEE C57.12.10
50 – 300 MVA
115 – 345 kV (±15° to ±30°)
IEEE C57.12.10
K-13/K-20/K-30 | 1,500 Vdc secondary for HV PV strings | 150% BESS overloading | ANSI C57.159, IEEE 1547, NEC 690
34.5 kV collector to 115/138 kV | IEC 61400-1 ed.4 / IECRE OD-501 | PD tested per IEEE C57.113
6, 12, 18, 24-pulse winding configurations | K-4/K-7/K-13 | Phase-shift 15°/20°/30° | IEEE C57.18.10
Zigzag or wye-delta | Short-time rated 10 sec / 1 min | NEC 250 | Optional NGR package | 5 kVA – 1,000 kVA
5 – 167 kVA | ANSI C57.12.20 | CSP or plain tank | DOE 2016 compliant
5 – 100 MVA, 34.5 – 230 kV | Trailer-mounted, DOT/FHWA | Quick-connect HV/LV bus | NERC CIP / FEMA ready
| Standard | Description |
|---|---|
| IEEE C57.12.00 | General requirements — liquid-immersed distribution, power and regulating transformers |
| IEEE C57.12.10 | Safety requirements — liquid-filled power transformers ≤1000 MVA |
| IEEE C57.12.34 | Pad-mounted, compartmental-type, self-cooled, three-phase distribution transformers |
| IEEE C57.116 | Guide for transformers directly connected to generators (GSU standard) |
| IEEE C57.110 | K-factor rating — capability when supplying non-sinusoidal (inverter) load currents |
| ANSI C57.12.20 | Overhead-type distribution transformers, 500 kVA and smaller |
| DOE 10 CFR 431 | Mandatory minimum efficiency — DOE 2016 compliant |
| NESC C2 / NEC | National Electrical Safety Code / National Electrical Code installation requirements |
| IEEE 693 | Seismic design of substations — available on request |
| NERC FAC-001/002 | Generator and transmission interconnection standards — LGIA/SGIA compliant |
| FERC Order 2003 & 2023 | Generator interconnection procedures — compliant engineering documentation |
| Buy American Act (BABA) | Compliant manufacturing on request |
For US grid, utility, and renewable energy enquiries — please include voltage class, MVA rating, applicable IEEE standard, and project state in your enquiry for fastest response.
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