# Astor 40 MVA 154/34.5 kV No-Load Tap-Changing (NLTC) Substation Power Transformer

> Astor 40 MVA 154/34.5 kV No-Load Tap-Changing (NLTC) Substation Power Transformer belongs to the Substation Step-Down Power Transformers (110-330 kV) category and is rated at 40 MVA with 154/34.5 kV primary/secondary voltage. Application: 154 kV National Grid to 34.5 kV Main Step-Down Power Transformer. Final ratings must be verified against the manufacturer datasheet.

> SKU: VF-AST-NLTC-40M-154 | Brand: Astor Enerji | Category: Power & Energy Equipment / Transformers / High-Voltage & Transmission Power Transformers / Substation Step-Down Power Transformers (110-330 kV)

**Voltformer canonical:** https://voltformer.com/product/astor-40-mva-154-34-5-kv-nltc-substation-power-transformer - markdown version: https://voltformer.com/product/astor-40-mva-154-34-5-kv-nltc-substation-power-transformer.md

## Overview

Astor 40 MVA 154/34.5 kV No-Load Tap-Changing (NLTC) Substation Power Transformer is intended for 154 kV National Grid to 34.5 kV Main Step-Down Power Transformer. Configured electrical data: 40 MVA, 154/34.5 kV primary/secondary voltage, 50 Hz, 3-phase, vector group YNd11 and short-circuit impedance 11%. 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:** [Astor Enerji](https://voltformer.com/brand/astor-enerji.md) - Turkey's transformer production giant Astor Enerji manufactures oil-immersed hermetic, cast-resin dry-type and power transformers up to 800 kV in its modern 140,000 m² facilities in Ankara ASO 2. OSB,
- **Category:** [Power & Energy Equipment](https://voltformer.com/catalog.md) / **Transformers** / [High-Voltage & Transmission Power Transformers](https://voltformer.com/category/power-transmission-transformers.md): 5 MVA–1000 MVA 110 kV, 154 kV, 380 kV, 500 kV and 1000 kV UHV AC/DC transmission and interconnection power transformers. / [Substation Step-Down Power Transformers (110-330 kV)](https://voltformer.com/category/power-transmission-transformers/substation-step-down-power-transformers.md)

## Technical Specifications

| Property | Value |
|---|---|
| Rated power | 40 MVA |
| Primary / secondary voltage | 154 kV / 34.5 kV (±2 x 2.5% NLTC) |
| Frequency / phases | 50 Hz / 3-phase - YNd11 |
| Short-circuit impedance (Uk) | 11% |
| No-load loss P0 | 23.00 kW |
| Load loss Pk | 138.0 kW |
| Calculated efficiency (power factor = 1) | 99.5991% at 100% load; 99.7133% 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 | 51000 kg - 6100×3600×4550 mm |
| Enclosure | IP55 / switchyard outdoor - wheel gauge: 1435 mm |
| LI / AC withstand | 650 kV peak / 275 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:** Vacuum On-Load Tap Changer (MR Reinhausen / TBEA OLTC), Buchholz Relay, Winding & Oil Temperature Indicators, Pressure Relief Device, Silica Gel Dehydrating Breather
**Optional:** Online DGA 8-Gas Dissolved Gas Analyzer, Fiber Optic Temperature Measurement System, Automatic Fire Suppression System

## Official sources

- https://astoras.com.tr/

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

Manufacturer family/application source. Astor Enerji 40 MVA 154/34.5 kV boşta kademeli indirici güç transformatörleri; TEİAŞ ve OSB şartnamelerine uygun olarak yüksek kısa devre dinamik dayanımıyla üretilir. 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-AST-NLTC-40M-154","quantity":1}]}
```

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