Oil-Immersed Transformer

S11-M Series Oil-Immersed Distribution Transformer

The S11-M is a fully sealed, three-phase oil-immersed transformer for industrial power distribution. Its corrugated tank accommodates oil expansion without a separate conservator, helping limit oil contact with ambient air.

The catalogue describes 50 Hz service on 10 kV- and 20 kV-class networks, with a cold-rolled silicon-steel core, copper windings and Dyn11 connection. Capacity, secondary voltage, tapping and guaranteed losses are specified for the requested configuration.

Technical Specifications

HV Voltage	10 / 20 kV class
Vector Group	Dyn11
Rated Frequency	50 Hz
Core Material	Cold-rolled silicon steel
Tank Construction	Fully sealed
Standards	GB 1094 / GB/T 6451-2015 / GB/T 25289-2010 / IEC 76

Key Features

Fully sealed corrugated tank without a separate conservator.
Copper windings and a cold-rolled silicon-steel core.
50 Hz supply; Dyn11 connection.
Capacity and guaranteed losses specified for the project.

Typical Applications

Petroleum and chemical plants
Metallurgical plants
Textile and light-industry factories

Installation & Aftercare

Prepare the site, plan routine checks and keep service records.

What needs to be ready before installation?

The catalogue describes indoor or outdoor installations below 1000 m altitude, excluding fire or explosion hazards and severe corrosive pollution.
Provide a foundation suited to the unit mass, clear airflow around tank cooling surfaces and access to bushings and accessories.
Coordinate earthing, cable connections and oil containment with the site layout; retain a route for eventual transformer removal.

What should operators check during routine rounds?

During rounds, observe load and temperature indications where fitted; look for leaks, damaged bushings or a change in normal sound.

What is covered during planned maintenance?

At planned isolation, qualified personnel clean accessible bushings and cooling surfaces and inspect terminals, seals and earthing connections.
Oil sampling and dielectric or moisture testing follow the unit’s service plan; investigate leakage or abnormal heating without opening the sealed tank routinely.

Customization Options

Define the electrical configuration and the details needed for your site.

Capacity & voltage: Specify capacity, primary and secondary voltages and the required 50 Hz duty.
Connection & taps: Dyn11 is described in the catalogue; agree the tapping range and adjustment method when ordering.
Losses & impedance: Required no-load and load losses, short-circuit impedance and compatibility with any units operating in parallel.
Site & installation: Foundation footprint, terminal positions, cable connections and oil-containment interface; declare altitude and environmental exposure.
Monitoring & finish: Temperature or oil-level indication, alarm contacts, corrosion protection, paint colour and nameplate language.

Project-specific options and accessories are confirmed in the quotation and approved drawings.