In August 2026, the SFZ-20000/33-11 three-phase oil-immersed on-load tap-changing power transformer, independently designed and manufactured by Ningbo Tianan, together with nine KYN61-40.5/1250A-31.5kA armored withdrawable high-voltage switchgear panels, completed the full set of factory tests and were formally packed and shipped, to be delivered to the project site in Zambia by sea freight.

This project features integrated turnkey delivery of the main transformer and high-voltage switchgear, with all core primary equipment in the substation supplied from a single source, facilitating on-site installation and interconnection as well as subsequent operation and maintenance for overseas projects.

I. Product Configuration and Adaptation to Local Operating Conditions

SFZ-20000/33-11 Main Transformer

Rated capacity: 20,000 kVA; voltage class: 33/11 kV; vector group: YNd11

Cooling method: ONAN/ONAF

Equipped with an on-load tap changer, enabling voltage-step regulation without power interruption — well suited to the heavily fluctuating grid load conditions in Zambia.

In response to Zambia’s high-temperature and dusty environment, the equipment features an optimized temperature-rise margin, a reinforced sealed dust-proof structure, and low-loss core material, reducing long-term operating losses and enhancing operating reliability under outdoor conditions in Africa.

KYN61-40.5 Armored Withdrawable High-Voltage Switchgear

A total of nine panels are delivered in this shipment, rated 40.5 kV, with a rated current of 1,250 A and a short-time withstand current of 31.5 kA, serving the control, protection and monitoring of the 33 kV distribution circuits.

The switchgear incorporates complete five-prevention interlocking to reduce the risk of misoperation on site. It adopts an armored compartmentalized structure and is configured with pressure-relief channels. The product complies with IEC 62271-200 and GB/T 3906, and is adapted to the operating conditions of indoor substations in Africa.

II. Full-Process Manufacturing and Factory Quality Control

From incoming raw-material inspection, component machining, active-part assembly and insulation treatment through to final assembly, the entire process for this batch of equipment is carried out under standardized process control.

The transformer has completed the full set of factory tests, including winding DC resistance, ratio and vector group, insulation, withstand voltage, no-load loss and load loss;

The switchgear has completed loop resistance, mechanical characteristics, power-frequency withstand voltage and interlocking verification tests.

All equipment may be released from the factory and shipped only after every technical indicator meets the requirements of the contractual technical agreement. The integrated single-source supply model reduces the risks associated with cross-coordination among multiple suppliers and facilitates delivery and O&M for overseas projects.

III. Continued Expansion in the African Power Infrastructure Market

This shipment marks yet another batch of equipment delivered by Tianan Electric to the Zambian market in 2026. As early as June 2026, the company had already delivered distribution transformers of multiple specifications — including 2,000 kVA, 1,250 kVA and 200 kVA models — to Zambia, serving local distribution-network upgrade and renovation projects.

In recent years, Tianan Electric has continued to deepen its presence in the African power market, with equipment deployed in Zambia, Rwanda, Kenya, Ethiopia and other countries, covering substation new-build and renovation/expansion projects. The company has developed the capability for integrated supply of distribution transformers, main transformers, medium-voltage switchgear and packaged substations. everaging the technical and capacity reserves of its Ningbo manufacturing base, the company continues to provide power equipment support for power-grid infrastructure construction in Africa.

News FAQ

Q: What equipment did Ningbo Tianan ship to Zambia this time?

A: One SFZ-20000/33-11 oil-immersed on-load tap-changing transformer, and nine KYN61-40.5 armored withdrawable high-voltage switchgear panels.

Q: What local operating conditions in Zambia is the equipment adapted to?

A: In response to the local characteristics of high temperature, heavy dust and large grid-load fluctuations, the transformer features a reinforced sealed dust-proof design and an enlarged temperature-rise margin, and is configured with an on-load tap changer; the switchgear complies with IEC international standards and is adapted to the conditions of indoor substations in Africa.

Q: In which African countries does Tianan Electric have projects?

A: Its products have been deployed in Zambia, Rwanda, Kenya and Ethiopia, among others, with integrated supply capability covering transformers, switchgear and packaged substations.

Q: What standards does this batch of products comply with?

A: IEC 62271-200 and GB/T 3906, while also meeting the project’s contractual technical agreement.