OIL-IMMERSED TRANSFORMER
Product Overview
The S11-M series oil immersed power transformer is a three-phase, fully sealed distribution transformer designed for reliable operation in 50Hz or 60Hz power networks.
Manufactured by Shengxian Electric Power Technology, this transformer combines low loss, low noise, and high efficiency to deliver excellent energy savings while reducing environmental pollution.
Whether you are upgrading an existing substation, expanding a factory, or building a new solar farm, the S11-M series offers a robust and cost-effective solution for step-down or step-up voltage regulation.
Shengxian Electric Power Technology develops and produces the S11-M series fully sealed oil-immersed power transformer, specifically engineered for long-term industrial and grid applications with following advantages:
️ ️ Strong Overload Capacity： Excellent heat dissipation via oil circulation, handles short-term overload without damage.
Fully Sealed Structure： Prevents oil leakage and oxidation, reducing maintenance frequency.
Customization Support： OEM/ODM available. Tap changers (OLTC), color, and impedance adjusted to your grid needs.
Global Compliance： Certified strictly to IEC 60076 standards
Materials & Manufacturing
Core Material
We use high-permeability CRGO silicon steel (cold-rolled grain-oriented) with step-lap core construction. This minimizes hysteresis loss and eddy current loss, improving overall efficiency.
Windings
Winding material is oxygen-free copper as standard. Aluminum windings are available for budget-sensitive projects. All windings are tightly wound to withstand short-circuit forces.
Insulation System
High-grade mineral oil provides excellent dielectric strength and cooling performance. Biodegradable synthetic oil is available for environmentally sensitive projects.
Tank Design
The corrugated fin tank serves two purposes: oil expansion and heat dissipation. No separate oil conservator is needed, which reduces maintenance.
Painting & Coating
External surfaces are treated with rust-proof primer and finished with UV-resistant powder coating. Color can be customized (RAL code).
Oil preservation system | How it works | Maintenance implication | When it is the right choice |
|---|---|---|---|
Free-breathing with conservator + dehydrating breather | Oil expands into an expansion tank vented through a desiccant breather; moisture is intercepted before air contacts the oil | Desiccant inspection/replacement; periodic conservator internal inspection (every 5–6 years on diaphragm-equipped units) | Site has maintenance capability for routine breather checks; cost-sensitive projects where oil treatment infrastructure exists |
Sealed conservator (diaphragm/air cell) | A flexible barrier separates oil from atmosphere; transformer “breathes” without direct oil–air contact | No desiccant replacement on maintenance-free breather designs; diaphragm integrity check every 5–6 years | Default recommendation for most export distribution/substation projects — balanced between cost and reduced oil oxidation risk |
Nitrogen-blanketed sealed tank | Dry inert gas maintains positive pressure (typically 0.5–5.0 PSI) above the oil; no breathing to atmosphere | Requires nitrogen bottle/regulator system, pressure gauge monitoring; tank pressure must never reach zero or negative | High-humidity or polluted outdoor sites where oxygen/moisture ingress risk is the dominant lifecycle concern, and owner accepts gas-system monitoring duty |
If your O&M team cannot commit to breather/desiccant checks, do not select free-breathing; the apparent lower first cost will be offset by accelerated oil oxidation. If your site has no capability to monitor nitrogen pressure, a nitrogen-blanketed design introduces a new failure mode rather than reducing one.
Why Choose Our Oil-Immersed Transformers？
1. Superior Core & Winding Design
We utilize high-permeability CRGO （Cold-rolled grain-oriented） silicon steel sheets processed through a step-lap technique. This minimizes exciting current and core loss. The windings are tightly wound to withstand short-circuit forces, preventing deformation during grid failures .
2. Advanced Oil Immersed Cooling System
The transformer is filled with high-grade mineral oil or biodegradable synthetic oil, providing excellent dielectric strength. The tank is equipped with corrugated fins or radiators, allowing natural air circulation （ONAN） to keep the temperature rise under strict limits （65K for winding） .
3. Stringent Quality Testing
Before leaving the factory, each unit undergoes 100% testing, including:
Short-circuit withstand test
Partial Discharge （PD） measurement
Impulse voltage test
Sealing test （ensuring zero leakage）
Applications
Our transformers are versatile and suitable for harsh environments:
Power Plants & Substations： Reliable step-up/down for grid transmission.
Industrial Facilities： Stable power supply for mines, cement plants, and manufacturing lines.
Renewable Energy： Specifically designed for Solar PV and Wind power step-up applications .
Commercial Buildings： Indoor/Outdoor distribution for shopping malls or hospitals.
DETAILED PICTURES
Why Partner With Us？
Experience & Expertise： Over 10 years of experience in manufacturing power equipment. Our 1factory is equipped with automated production lines.
Global Export： We have successfully exported to the US, Europe, Southeast Asia, and Africa.
Fast Delivery： Raw materials in stock, lead time usually 15-30 days .
️ After-Sales Service： 12 months warranty. 24/7 technical support and lifetime consulting service.
