Distribution Transformers, Built for Reliable Power Delivery
Distribution transformers form the final stage of electrical power transformation, stepping medium-voltage electricity down to the usable voltage required by homes, commercial facilities, industries, and local distribution networks.
MDP Power Tech manufactures three-phase distribution transformers in the 25 kVA to 315 kVA range. The transformers are engineered through a precision-driven process beginning with high-grade CRGO core selection to achieve minimal losses and high efficiency. Windings are designed using copper or aluminium conductors with superior insulation for dependable electrical performance.
The active components are assembled, dried under controlled conditions, and securely tanked to maintain structural integrity and moisture resistance. This disciplined process results in a robust transformer designed for long service life, safety, and reliable power delivery.
Each unit undergoes rigorous routine and applicable type testing as per BIS and IS/IEC requirements, including efficiency, insulation, impedance, voltage ratio, losses, temperature rise, and high-voltage withstand checks before certification and dispatch.
Our engineering team can work with customers to match the transformer configuration to the required capacity, voltage class, mounting arrangement, load profile, and project requirements.
Key Features
High Efficiency
Rated efficiency of ≥98%, with voltage regulation maintained below 5% across the operating range.
Robust Construction
CRGO core lamination with copper or aluminium windings, Class A/F insulation, and IP55 protection.
Flexible Installation
Suitable for plinth and pole mounting, with off-circuit tap arrangements as specified by the customer.
Technical Specifications
Standard electrical and construction specifications for the MDP Power Tech distribution transformer range. Custom configurations can be developed according to customer and project requirements.
| No. | Item | Specification |
|---|---|---|
| 1 | Capacity Rating | 25 kVA – 315 kVA |
| 2 | Voltage Rating | 11/0.433 kV |
| 3 | Frequency | 50 Hz |
| 4 | Phase | Three-phase |
| 5 | Efficiency | ≥ 98% |
| 6 | Voltage Regulation | < 5% |
| 7 | Vector Group | Dyn11 |
| 8 | Insulation Class | Class A/F |
| 9 | Cooling Type | ONAN |
| 10 | Core Material | CRGO Core Lamination |
| 11 | Winding Material | Copper / Aluminium |
| 12 | Impedance | 4.5% |
| 13 | Temperature Rise | 35°C Oil / 40°C Winding |
| 14 | Protection Rating | IP55 |
| 15 | Mounting | Plinth / Pole |
| 16 | Tap Changer | Off-circuit, as per customer specification |
| 17 | Testing Standard | Latest applicable IS / IEC |
| 18 | Quality Certification | ISO 9001:2015 |
Manufacturing Process
Every distribution transformer passes through a controlled, process-driven manufacturing sequence designed to maintain consistency, electrical performance, and mechanical strength.
The transformer core is built from high-grade CRGO (cold-rolled grain-oriented) electrical steel laminations, precision-cut and stacked to form an efficient magnetic circuit that minimizes core losses. Copper or aluminium windings are wound and insulated to exact specifications, then assembled around the core with controlled clamping pressure to ensure mechanical strength, dimensional accuracy, and optimal electrical performance.
The transformer tank is fabricated from heavy-gauge mild steel sheets, cut and welded to precise dimensions to house the core-coil assembly. Radiators and cooling fins are integrated for effective heat dissipation, and the tank undergoes surface treatment and rigorous leak testing before being sealed for oil filling, ensuring long-term durability and protection against environmental stress.
This disciplined, stage-by-stage approach, combined with skilled manpower and a quality-controlled manufacturing environment, supports consistent performance across the distribution transformer range.
Testing & Quality
Post assembly, the core-coil unit undergoes controlled vacuum drying to remove residual moisture trapped within the insulation and windings. Using controlled temperature and high-vacuum conditions, this process helps improve dielectric strength, insulation life, and long-term reliability.
The tank is then filled with high-dielectric-strength transformer oil under controlled conditions to minimize moisture and air pockets while providing effective insulation and cooling.
Each unit undergoes a comprehensive round of routine and applicable type tests as per IS/IEC requirements, including insulation resistance, winding resistance, voltage ratio, no-load and load loss, temperature rise, and high-voltage withstand tests. Quality checkpoints are verified throughout manufacturing before certification and dispatch.
MDP Power Tech's designs are type tested in NABL-accredited laboratories such as CPRI and ERTO, India. The company's manufacturing documentation also records type testing covering Temperature Rise, Lightning Impulse, Short Circuit and other applicable tests.
Transformer Losses & Energy Efficiency
The following comparison is reproduced from the MDP Power Tech brochure as a reference to the maximum total losses for up to 11 kV class transformers under the stated BIS guideline table. Actual project guarantees should be confirmed against the applicable purchase specification and agreed energy-efficiency level.
| Rating | Impedance | Energy Efficiency Level 1 | Energy Efficiency Level 2 | ||
|---|---|---|---|---|---|
| 50% Load | 100% Load | 50% Load | 100% Load | ||
| 25 kVA | 4.5% | 190 W | 635 W | 175 W | 595 W |
| 63 kVA | 4.5% | 340 W | 1,140 W | 300 W | 1,050 W |
| 100 kVA | 4.5% | 475 W | 1,650 W | 435 W | 1,500 W |
| 160 kVA | 4.5% | 670 W | 1,950 W | 570 W | 1,700 W |
| 200 kVA | 4.5% | 780 W | 2,300 W | 670 W | 2,100 W |
| 250 kVA | 4.5% | 980 W | 2,930 W | 920 W | 2,700 W |
| 315 kVA | 4.5% | 1,025 W | 3,100 W | 955 W | 2,750 W |
Note: For non-preferred ratings, maximum losses are subject to agreement between the user and supplier. The complete brochure table also covers higher ratings beyond the standard MDP distribution transformer range shown on this page.
Where Our Distribution Transformers Are Used
Built for dependable medium-voltage to low-voltage transformation, our distribution transformers support utility networks, residential developments, commercial infrastructure, and industrial installations.
Utility Distribution Networks
Suitable for distribution substations and local grid networks requiring dependable step-down transformation from medium-voltage supply to consumer-level voltage.
Residential Developments
Supporting reliable electricity distribution for residential colonies, housing developments, and community-level electrical networks.
Commercial Facilities
Providing stable low-voltage power for commercial complexes, institutional buildings, offices, and other infrastructure facilities.
Industrial Applications
Suitable for factories, workshops, processing facilities, and industrial installations requiring reliable local power distribution.
Frequently Asked Questions
What is a distribution transformer?
A distribution transformer steps medium-voltage electrical power down to lower voltage levels used by residential, commercial, industrial, and other end-use installations.
What distribution transformer ratings does MDP Power Tech offer?
The current MDP Power Tech brochure specifies a standard three-phase distribution transformer range from 25 kVA to 315 kVA, with a standard voltage rating of 11/0.433 kV.
What winding materials are available?
The brochure specifies copper or aluminium winding options, depending on the required specification and application.
Can the transformer be pole mounted?
Yes. The stated distribution transformer specification supports both plinth and pole mounting configurations, subject to the selected rating and project requirements.
What testing is carried out before dispatch?
Transformers undergo routine and applicable type testing, including insulation resistance, winding resistance, voltage ratio, no-load and load loss, temperature rise, and high-voltage withstand tests.
Can the transformer be customized?
Yes. Configuration can be developed according to customer, utility, site, mounting, voltage, and application requirements.