MPT
Medium power transformer, 230 / 345 kV HV voltage rating
MPT
- Documented US-market variants with 230 kV and 345 kV HV voltage rating — ANSI C57.12.00, conservator-type oil preservation
- On-load tap changer with motorized drive keeps output voltage constant; de-energized tap changer optionally combinable
- Loss-optimized designs — efficiencies above 99 % are standard across the Siemens Energy power transformer range
- Alternative insulating liquids available (synthetic and natural esters — biodegradable, silicone oil) for locations with high safety and environmental requirements
- Digital monitoring option: Sensformer Advanced / Edge with thermal digital twin (24 h load-scenario simulation, permissible-overload and aging calculation); SITRAM DGA monitors available as accessories
Network transformer serviceMachine transformer applications230/345 kV substation supply
Sign in to see your price, availability and framework terms for MPT.
Horizon-3 pattern: this exact page gains commerce powers on sign-in — the URL never changes.
SIMULATED · ASK-AN-EXPERT PILOT DEMO
Ask an expert about MPT
15 minutes with the right transformers specialist — question in, booked call out. No email archaeology.
Checking availability…
Specifications
Main
| Product type | Medium power transformer, oil-immersed, three-phase |
| Application | Network and machine transformer (family also covers single-phase, multi-winding and autotransformer designs) |
| Voltage regulation | On-load tap changer (OLTC) with motor drive; de-energized tap changer optional |
| Oil preservation | Conservator tank system (documented example, drawing US-25) |
| Insulating liquid | Mineral oil; alternatives: synthetic ester, natural ester (biodegradable), silicone oil |
| Digital option | Sensformer Advanced / Edge monitoring with thermal digital twin; SITRAM DGA monitors as accessories |
Electrical ratings (documented example configuration, drawing US-25)
| HV voltage class variants | 230 kV / 345 kV |
| Rated power | 75 / 100 / 133 / 167 MVA (cooling-stage dependent) |
| Voltage ratio | 345 x 230 / 34.5 kV (D / Y) |
| Phases / frequency | 3-phase, 60 Hz (documented example; 50 Hz IEC designs available in family) |
| Winding temperature rise | 65 °C |
| Efficiency | > 99 % (family-typical per Siemens Energy brochure) |
Mechanical & environment
| Cooling stages (example) | ONAN / ONAF / ONAF / OFAF; family options include ODAF, OFWF, ODWF |
| Approx. footprint (example, US-25) | 14,605 x 7,620 mm (approximate, preliminary drawing) |
| Approx. height over HV bushing (example, US-25) | 9,271 mm (approximate, preliminary drawing) |
| Fittings (example) | Cover-mounted HV/LV/H0X0 bushings, detachable radiators, forced-air cooling fans, oil pump, OLTC motor drive, control cabinet, conservator tank |
| End-of-life recyclability | > 95 % of materials (Siemens Energy whitepaper) |
Standards & certifications
| Standards (documented example) | ANSI C57.12.00 |
| Standards (family design basis) | IEC 60076; other international and national standards (ANSI/IEEE, IEC) on request |
| Quality management | All transformer factories certified, e.g. DIN ISO 9001 |
Options & variants
Variant set as published in Siemens Energy web-catalog media (Service-Media-2026, Power_Transformer_Shell_NL). Both variants ship the same preliminary outline drawing US-25; weights and dimensions on it are approximate and not for construction.
| Variant | HV voltage class | Standards basis | Documented example rating |
|---|---|---|---|
| MPT with 230 kV HV voltage rating | 230 kV | ANSI C57.12.00 | shares outline drawing US-25 |
| MPT with 345 kV HV voltage rating | 345 kV | ANSI C57.12.00 | 75/100/133/167 MVA, 345 x 230 / 34.5 kV (D/Y), ONAN/ONAF/ONAF/OFAF |
Compatible accessories
monitoring
SITRAM Multisense 5 — multi-gas DGA monitor (H2, CO, C2H2, C2H4 + moisture in oil)
monitoring
SITRAM Multisense 9 — multi-gas DGA monitor (8 dissolved gases + moisture)
monitoring
SITRAM H2Guard — hydrogen-in-oil monitor
digitalization
Sensformer Advanced / Edge — digital monitoring layer with thermal digital twin
Documents & downloads
Brochure Power transformers — machine and network transformers from 30 to over 1,300 MVA (Siemens Energy family brochure, 2024)
Whitepaper Sustainable power transformers — efficiency, ester insulation, Sensformer digital twin (Siemens Energy, 2022)
Drawing Outline sketch US-25 — 75/100/133/167 MVA, 345 x 230 / 34.5 kV example configuration (metric & imperial)
Manual SITRAM Multisense 5 — installation and operation manual (DGA monitoring accessory)
Also covered in the technical library
Brochure Power Transformers – Machine and Network Transformers from 30 to over 1,300 MVA
Brochure Siemens Energy Design Programs for Power Transformers — Integrated Tools for Highly Sophisticated Solutions
Brochure Transformers digitalization — Noedra Node suite for substation digitalization
Brochure Trusted Partner in the Energy Transition — Sustainable Power Transformers
Related products
LPT-GSU Large power / generator step-up transformer, ≤ 1,400 MVA
≤ 1,400 MVA · ≤ 765 kV · 50 / 60 Hz Datasheet · Dimensions ↓
SR