# Siemens Energy 40 MVA 110/10.5-6.3 kV Dual-Secondary Power Plant Auxiliary Service Transformer

> Siemens Energy 40 MVA 110/10.5-6.3 kV split secondary power plant station service transformer.

> SKU: VF-SIE-AUX-40M-110 | Brand: Siemens Energy | Category: Power & Energy Equipment / Transformers / Distribution Transformers / Oil-Immersed Conservator Transformers

**Voltformer canonical:** https://voltformer.com/product/siemens-energy-40-mva-110-10-5-6-3-kv-auxiliary-service-transformer - markdown version: https://voltformer.com/product/siemens-energy-40-mva-110-10-5-6-3-kv-auxiliary-service-transformer.md

## Overview

Siemens Energy 40 MVA 110/10.5-6.3 kV Dual-Secondary Power Plant Auxiliary Service Transformer is intended for 154 kV National Grid to 34.5 kV Main Step-Down Power Transformer. Configured electrical data: 40 MVA, 110/10.5 kV primary/secondary voltage, 50 Hz, 3-phase, vector group YNd11-d11 and short-circuit impedance 12%. Construction: Copper (Cu-Cu); cooling: ONAN/ONAF; loss class: Ecodesign Tier 2. These values support preliminary engineering selection; verify insulation levels, thermal limits, short-circuit duty, installation conditions and applicable standards against the manufacturer datasheet and the site study.

- **Application:** 154 kV National Grid to 34.5 kV Main Step-Down Power Transformer
- **Target industries:** National Transmission Grid Network, Major Power Plants (Hydro & Wind), Mega Industrial Zone Grid Infeeds
- **Brand:** [Siemens Energy](https://voltformer.com/brand/siemens-energy.md) - The embodiment of German engineering excellence; Siemens Energy sets the industry standard with GEAFOL® cast-resin dry-type transformers, ester-oil network units and transmission-level autotransformer
- **Category:** [Power & Energy Equipment](https://voltformer.com/catalog.md) / **Transformers** / [Distribution Transformers](https://voltformer.com/category/distribution-transformers.md): 50 kVA–3150 kVA oil-immersed hermetic, conservator and cast-resin dry-type medium-voltage distribution transformers. / [Oil-Immersed Conservator Transformers](https://voltformer.com/category/distribution-transformers/oil-immersed-conservator-tank-transformers.md)

## Technical Specifications

| Property | Value |
|---|---|
| Rated power | 40 MVA |
| Primary / secondary voltage | 110 kV / 10.5 kV (±8 x 1.25% (OLTC on-load tap-changing)) |
| Frequency / phases | 50 Hz / 3-phase - YNd11-d11 |
| Short-circuit impedance (Uk) | 12% |
| No-load loss P0 | 22.00 kW |
| Load loss Pk | 140.0 kW |
| Calculated efficiency (power factor = 1) | 99.5966% at 100% load; 99.7158% at 50% load |
| Loss class | Ecodesign Tier 2 |
| Windings | Copper (Cu-Cu) - cooling: ONAN/ONAF - insulation: Class A |
| Temperature rise | 65 K - sound pressure: 68 dB(A) |
| Mass and dimensions | 54000 kg - 6100×3750×4500 mm |
| Enclosure | IP55 / switchyard outdoor - wheel gauge: 1435 mm |
| LI / AC withstand | 480 kV peak / 200 kV rms - partial discharge: 5 pC |
| Environment | -25°C / +40°C; altitude ≤ 1000 m |
| Core steel | CRGO Laser-Treated Grain-Oriented Silicon Steel (23ZDMH85 / Baosteel B23R085) |
| Bushings / terminals | Direct Copper Busbar Terminals (Busbar Integrated / IP00-IP31) |

## Standards

- IEC 60076 series
- TEİAŞ technical specification
- TS EN 60076
- KEMA & CESI type-test approved

## Accessories

**Included:** Configuration-specific technical value, Configuration-specific technical value, Configuration-specific technical value, Configuration-specific technical value
**Optional:** Online DGA, Configuration-specific technical value

## Official sources

- https://www.siemens-energy.com/global/en/offerings/power-transmission/transformers.html
- https://www.siemensenergy.com/global/en/home/products-services/product-offerings/transformers.html

- **Source scope:** manufacturer-family
- **Last reviewed:** 2026-09-13

Manufacturer family/application source. Siemens Energy power plant auxiliary service transformers (Eigenbedarfstransformatoren) provide high reliability and split dual secondary outputs to feed critical station auxiliary drives, cooling pumps and plant buses. Exact order code, guaranteed losses, dimensions, insulation level, cooling stage, winding material and project options must be confirmed with the OEM before procurement or an SLD study.

## Pricing & Logistics

- Pricing type: RFQ (On Request) - Indicative range: $420,000 – $510,000 USD
- Delivery time: 2–8 weeks (may vary depending on technical configuration, factory capacity and destination) - Warranty: 36 months
- Compliance candidates: IEC 60076 series, TEİAŞ technical specification, TS EN 60076, KEMA & CESI type-test approved. Verify applicability and conformity against the exact offered model and project jurisdiction.

## RFQ

Request a formal factory quotation via Voltformer RFQ:

```json
POST https://voltformer.com/api/v1/rfq
{"companyName":"Example Energy","email":"procurement@example.com","items":[{"skuOrId":"VF-SIE-AUX-40M-110","quantity":1}]}
```

Full catalog JSON: https://voltformer.com/agent-catalog.json - OpenAPI: https://voltformer.com/openapi.json