40MVA Utility Substation Conservator Transformer 44kV to 34.5kV Oil Immersed ONAN CSA Standards

Designed for utility substations and large industrial power systems, this 40 MVA conservator-type power transformer provides 44000V to 34500Y/19920V step-down service for high-capacity grounded-wye distribution. It is built with copper windings, mineral-oil insulation, a Dyn1 connection and ONAN cooling, and complies with IEEE/ANSI C57.12.00 and C57.12.34.

The single-unit 40 MVA capacity, which allows a 44kV source to supply a substantial 34.5kV distribution bus from one transformer position. Compared with dividing the same duty among multiple smaller units, this arrangement can reduce equipment footprint, primary and secondary interconnections, foundation requirements and system coordination work.

• Single-Unit 40MVA Capacity

  The full 40MVA rating allows a single transformer position to supply a substantial 34.5kV distribution bus from a 44kV source. This can reduce the footprint, foundations, cable connections and coordination requirements associated with installing multiple smaller transformers.

• Conservator-Type Oil Expansion System

The conservator system accommodates insulating-oil expansion and contraction as transformer load and outdoor temperature change. Combined with the dehydrating breather and gas relay, it supports controlled oil-level management and continuous outdoor operation.

   

• Three top-mounted HV bushings — Provide the live-front connection points for the 44kV primary circuit.
• Three LV bushings and one X0 neutral bushing — Connect the 34500Y/19920V phases and grounded neutral to the downstream distribution system.
• Station-class surge arresters — Limit incoming overvoltage surges before they reach the transformer winding insulation.
• Conservator tank — Accommodates insulating-oil expansion and contraction during load and ambient-temperature changes.
• Gas relay — Detects gas accumulation or rapid oil movement associated with internal transformer conditions.
• Rapid pressure rise relay — Provides an indication when internal tank pressure increases abnormally fast.
• Automatic pressure relief device — Releases excessive internal pressure to protect the transformer tank.
• Magnetic oil level indicator — Provides a visible indication of the insulating-oil level.
• Oil temperature controller — Monitors top-oil temperature and supplies control or alarm contacts.
• Radiator fill and drain plugs — Support filling, draining and maintenance of the cooling sections.
• Drain valve with sampling connection — Allows insulating oil to be drained or sampled during maintenance and condition assessment.
• Tank and active-part lifting lugs — Provide designated lifting points for handling the tank and internal active assembly.
• Grounding terminals and tank grounding pads — Provide secure connection points for bonding the transformer tank to the station grounding system.

A: Winley provides clear capacity-based lead times after technical approval: 8-10 weeks for transformers below 10 MVA, 10-12 weeks for 10-40 MVA transformers, and 18-20 weeks for 40-100 MVA transformers. We also provide a detailed production schedule and real-time manufacturing photos to help track progress.We provide a detailed production schedule and real-time manufacturing photos to help track progress.

A: We offer a flexible MOQ of just 1 unit. Complete inquiries are quoted within 1-3 days with 24/7 support. Leveraging our extensive North American experience in renewable energy, data centers and large industrial projects, we ensure highly cost-effective and reliable solutions.

A: Yes, We accept OEM and ODM. Winley provides services for substation power  transformers up to 100MVA, with HV systems up to 145kV. We can customize electrical parameters, structure, fluid, protection, switches, gauges, tank and paint according to customer drawings, with the capability to integrate components from brands like Qualitrol, Eaton Cooper, and MR.

A: Yes. Winley substation transformers are engineered and manufactured in strict accordance with ANSI/IEEE, CSA, NEMA, relevant ASTM standards and IEC 60076.We bring a proven track record across the United States and Canada, supporting critical applications in industrial manufacturing, renewable energy, and power distribution across a range of capacity and voltage requirements.

A: We deliver a complete compliance package: approval drawings, datasheets, nameplate drawings, routine test reports, installation manuals and accessory manuals. We also back your project with lifetime documentation support.

A: Winley ensures quality through strict ISO 9001 process management with dedicated QC oversight. Prior to delivery, every unit undergoes comprehensive routine testing, including Winding Resistance, Turns Ratio, Polarity and Phase Relation, and No-Load Loss and Excitation Current tests. We also fully support Factory Acceptance Testing (FAT) and third-party inspections (SGS).

Q7: Do you provide logistics and transportation support for large-scale projects? 

A: Yes. Winley Electric provides tailored, fully controllable transportation solutions for large-scale transformer projects to ensure compliant customs clearance and zero-damage delivery. We actively assist in verifying critical logistics factors, including shipping dimensions, total weight, offloading conditions, site accessibility, and lifting/rigging requirements.

A: 24 months from B/L. During the warranty period, If there are any accessory problems, just provide photos of damaged accessory, then we will provide free service. According to the number of products, we will provide easily damaged accessories for free. We can also provide technical support if you need.