Complete Product Introduction

1. Product Brief Introduction

The S11-M-30/2500-20/10 type fully sealed oil-immersed transformer is suitable for power systems with AC 50Hz, rated working voltage of 10kV, 20kV and below. It is used as a distribution transformer in petroleum, metallurgy, chemical industry, textile, light industry and other enterprises as well as places with high dust concentration.

2. Model Meaning & Explanation

The coding of the product model has clear definition of each part, and the combination of letters and numbers contains the core parameters and structural characteristics of the product, the specific meaning is as follows:

• S: Three-phase
• 11: Design serial number
• M: Fully sealed
• □: Rated capacity (kVA)
• 20/10: High-voltage side voltage grade (kV)

3. Working Conditions

• Installation altitude: not exceeding 1000m;
• Ambient temperature: -40℃ ~ +40℃

4. Structural Characteristics

Iron Core

The iron core is made of high-grade grain-oriented cold-rolled silicon steel sheets. It is a core-type iron core with full oblique seam lap joint accumulated structure. The iron core column is a multi-stage stepped circular cross-section, and the iron yoke has the same cross-section as the iron core column.

Winding

The winding adopts terpene enameled wire, non-impregnated process and tight binding; all windings are concentric coils: the high-voltage winding has taps meeting the requirements of tap changing voltage, which are led to the tap changer. The tap changer is installed on the box cover, and the voltage transfer of 10kV and 20kV as well as tap changing voltage can be realized after cutting off the power supply.

Safety Protection Device

• Transformers of 30-2000kVA are equipped with pressure relief valves;
• Gas relays with alarm and trip terminals can be installed according to user requirements;

Oil Temperature Measuring Device

• All transformers are equipped with tube seats for glass thermometers, which are set at the top of the oil tank and extend into the oil by 120±10mm;
• 1000-2000kVA transformers are equipped with outdoor signal thermometers;

Transformer Oil Tank

The transformer oil tank is composed of corrugated radiators, with surface powder spraying and firm paint film. The corrugated radiator not only has cooling function, but also has "breathing" function. The elasticity of the corrugated radiator can compensate for the volume change of transformer oil caused by temperature rise and fall. Therefore, the fully sealed transformer has no oil conservator, which reduces the overall height of the transformer;

The transformer adopts vacuum oil filling process during installation, which completely removes moisture in the transformer and prevents transformer oil from contacting with air. It effectively prevents oxygen and moisture from entering the transformer, which leads to the decline of transformer insulation performance and aging of transformer oil, so oil sampling test is not required regularly;

5. Main Technical Parameters

Technical Parameter	Parameter Value
Type	S11-M-30/2500-20/10
Rated frequency	50Hz
Rated voltage (high-voltage side)	10kV / 20kV
Installation altitude	≤1000m
Operating temperature range	-40℃ ~ +40℃
Structural type	Fully sealed oil-immersed type
Core material	High-grade grain-oriented cold-rolled silicon steel sheet
Winding type	Concentric coil
Cooling method	Corrugated radiator cooling
Safety protection device	Pressure relief valve, gas relay (optional)
Temperature measuring device	Glass thermometer + signal thermometer (1000-2000kVA)
Oil filling process	Vacuum oil filling