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  • Product: Oil liquid filled transformer
  • Rated capacity: 5-31500kVA
  • Frequency: 50/60Hz
  • Primary voltage: 6,10,35kV
  • Secondary voltage: 0.69,0.4kV



Transformers/reactors/intelligent integrated substations-Smart Energy for Better Life



1. One of the drafters of the National Standard Mine Flameproof Mobile Substations (GB/T 8286-xxxx ), which will replace the existing national standard (GB/T 8286-2005 ) and it was submitted for trial in Beijing.

2. +20 years experience R&D team, derived from a 60 years of history transformer manufacturer in Changsha, Hunan, China since 1956.

3. Full range of transformer types with customized functions are available.

4. CE & ISO certificated.


Service Condition

A) Suitable for indoor or outdoor application

B) Air temperature: Maximum temperature: +40; Minimum temperature:-30

C) Humidity: Monthly average humidity 95%; Daily average humidity 90% .

D) Altitude above sea level: ≤1000m.

E) Max wind speed:35M/s

F) Ambient air not apparently polluted by corrosive and flammable gas, vapor etc.

G) No frequent violent shake



Below are the tests conducted by Varelen before delivery. Other tests required by clients can also be done accordingly.

Insulation resistance

Resistance of all windings

Check voltage ratio and vector group

No-load test at rated frequency and rated voltage

Impedance test

Withstand voltage test

Induced over-voltage withstand test

Partial discharge measurement

Oil leakage test


Product Features:

1. The three-limb iron core is made of oblique cut Grain-oriented, seven-step silicon steel lamination insulated on both sides, guaranteeing low losses and low noise. These values are even improved by laser treatment. It is protected on the surface with a flash-proof varnish in order to prevent the sheet from corrosion and to reduce the noise.


2. The winding

The winding as the centerpiece of the transformer must be especially protected – both against high electrical stress due to external over voltages and against mechanical overloads by short circuits. Varelen transformers are systematically designed to meet these requirements. The windings are made of copper or aluminum. Low-voltage windings are made of strip or flat wire, and the high voltage windings are manufactured from round or profile wire. (“diamond-dotted paper”) bonds the winding into a compact block while drying and increases the short-circuit capacity additionally.



3.  The Tank Whether during transport or operation –the tank must be absolutely tight under mechanical stress. Preconditions to achieve this are constructional experience, the most modern calculation methods and high-quality welding work. Special attention is paid to corrosion protection. Pretreatment of the surface is processed by phosphating pickling, contributes to corrosion protection, just like multi-coating with preset drying times for each layer. On request, hot-dip galvanization provides for even better protection.  


Technical Specification

Transformer type Oil-immersed type
Phases three 
Capaticy 5 to 31500kva
Frequency 50-60hz
Coolers corrugated wall or radiator
Cooling mode ONAN/ ONAF
Tap changer off-load or on-load
Winding materials Aluminum Copper
Standard IEC60076