Step down at high quality electrical power transformer 11kV 14.5kV 33kV
Rated frequency
50Hz
Rated capacity
5 MVA
Phases
Three-phase
Series
S11
Primary voltage
33kV
Cooling method
ONAN
Frequency
50/60 Hz
Description
he Vziman 5 MVA Step-Down Power Transformer is a robust, three-phase, oil-immersed unit engineered for demanding medium-voltage power transmission and distribution networks. Designed in strict accordance with IEC 60076 standards, this transformer serves as a critical interface between high-voltage transmission grids (33 kV) and local distribution networks (11 kV).
Featuring premium copper windings and an optimized magnetic core design, the Vziman transformer ensures minimal energy losses, superior short-circuit withstand capability, and stable voltage regulation for industrial parks, utility substations, and large-scale commercial complexes.
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Key Features
Precision Voltage Transformation: Optimized winding turn ratio design guarantees accurate step-down conversion from 33 kV to 11 kV, ensuring high power quality for downstream loads.
Superior Cooling Efficiency: The ONAN (Oil Natural Air Natural) cooling system, combined with high-efficiency radiators, ensures optimal heat dissipation even under continuous full-load operation.
High Mechanical Strength: The robust winding assembly utilizes high-conductivity copper and advanced clamping structures to withstand dynamic short-circuit forces.
Flexible Grid Integration: Compatible with multiple medium-voltage levels and equipped with a De-energized Tap Changer (DETC) for precise voltage adjustment.
Reliable Insulation System: High-grade mineral oil provides excellent dielectric strength and arc quenching properties, extending the equipment's service life.
Operating Environment
This transformer is designed to operate reliably under the following standard service conditions as per IEC 60076-1:
Installation: Indoor or Outdoor (Weatherproof construction).
Ambient Air Temperature:
Maximum: +40°C
Maximum 24-hour average: +30°C
Minimum: -25°C (Standard) / -40°C (Optional for extreme cold regions).
Altitude: ≤ 1000 meters above sea level. (For altitudes >1000 m, external insulation withstand voltage shall be increased by approximately 1% per 100 m, and temperature rise limits shall be reduced accordingly per IEC 60076-1).
Relative Humidity: ≤ 90% at 25°C.
Environment: Free from conductive dust, corrosive gases, and explosive media. The installation site should be free from severe vibration.
Replacement of 2x25MVA Power Transformers at an Old Substation in MadagascarThe on-site implementation took place at an old substation in a central city of Madagascar. The core tasks included the dismantling of old transformers, foundation renovation, unloading and installation of two 25MVA transformers, vacuum oil filling, and system commissioning. Vziman dispatched a team of technical experts to provide on-site guidance.01 Project Overview1.1Project BackgroundIn April 2026, two RMR-25000/35 35
What is the difference between on-load and off-circuit tap changer for transformers?
This transformer uses off-circuit tap changer, which requires power cut for adjustment with stable structure and low maintenance cost. It is ideal for distribution grids with relatively stable load, while on-load tap changer supports live voltage adjustment for fluctuating heavy-load grids.
Why use pure copper windings for medium voltage power transformers?
High-conductivity copper windings reduce winding resistance and power loss, improve heat dissipation efficiency, and enhance short-circuit withstand capability. Compared with aluminum windings, copper windings deliver longer service life and more stable long-term operation.
Can the transformer be installed indoors and outdoors?
Yes. The transformer adopts weatherproof construction, supporting both indoor substation installation and outdoor open-air installation. It adapts to various substation layout schemes and site conditions.
Main Categories: Medium and High Voltage Switchgear/Lighting and Monitoring Equipment/Power and Distribution Transformers/IT and AI Support Equipment/Lightning Protection and Electrical Insulation/Substations and E-Houses/Power Electronic Equipment/Electrical Panel and Controlgear
$28400.00
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Model
S11-5 MVA-33/11KV
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Whole-life care management services for equipment procurement, use, maintenance, and after-sales, ensuring safe operation of electrical equipment, continuous control, and worry-free electricity consumption.
The equipment supplier has passed platform qualification certification and technical evaluation, ensuring compliance, professionalism, and reliability from the source.
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