Email:i-trade1@lnjldq.comLiaoning Jinli Electric Power Electrical Appliance Co.,Ltd

Liaoning Jinli Electric Power Electrical Appliance Co.,Ltd

Vacuum on-Load Tap Changer for Oil Immersed Transformers Switch

Basic Info

  • Model NO.: 

  • Connection Method: Y,D

  • Trademark: Jinli

  • Specification: IEC CE, ISO

  • HS Code: 8535900090

  • Max Rated Current: 1000A 2400A

  • Rated Voltage: 4kv

  • Transport Package: Wooden Cases

  • Origin: Liaoning, 

Product Description

Vacuum On-Load Tap Changer For Oil Immersed Transformers switch



Until now, the oil-immersed on-load tap changer (hereinafter referred to as OLTC), being widely used in worldwide substation, inside which the oil is an insulation medium for OLTC themselves and for extinguishing arc occurred on the main switching contacts and transition contacts, as well as a medium for lubrication of mechanical parts and for cooling of contacts and all other currentcarrying parts. Therefore, this type OLTC is also called the OLTC of arc-extinguishing inside the oil. The carbonization of oil for this type of OLTC is inevitable during the operating of tap changer. 

With the switching times increasing, inside the OLTC oil chamber there will be more and more carbonizations. Therefore, except from neutral point connection, in application for other winding connections of transformer, or power transformer with voltage of 220kV or above, the auxiliary device like online oil filter plant has to be assembled with the oil-immersed OLTC in order to guarantee the insulation level of oil and to decrease the carbon granule. When this kind of OLTC is used in the rectification and furnace transformer, it operates very frequently under the full-load or even over-load, which quickens the wearing-out of arcing contacts, the carbonization of oil and also the wearing-out of mechanical parts. As a result, such works as continual changing of new oil and replacement of arcing contacts, frequent inspection and maintenance have to be done to make the OLTC reliable, even replacing the new OLTC within the service life of transformer, the cost for maintaining its normal operation is quite expensive.

The type of oil-immersed and vacuum arc-extinguishing OLTC, with arc contacts replaced by

vacuum interrupter, has very prominent advantages:

1. The current breaking in the vacuum interrupter, and the arc produced also extinguishing in the vacuum interrupter, which solved the problem of oil carbonization. Therefore there is no need to equip with online filter plant under any application condition.

2. Since the carbonization of oil in the oil compartment is eliminated, the carbon granule adhered to the surface of insulation material does not exist any longer, the insulation level is guaranteed.

3. The task of carrying current for long time is undertaken by special mechanical main contacts while the vacuum interrupter only taking the current instantly through, so the overload capacityof OLTC has been improved greatly.

4. All the vacuum interrupters are fixed firmly and mal-operation will not happen.

The highest voltage of the OLTC is 252kV, three-phase OLTC is application for neutral point winding connection of transformer with voltage up to 550kV, and single-phase OLTC can be used for any selectable winding connection, the max. rated through current of tap changer is 1000 Amp. in three-phase and 2400 Amp. in single-phase.
OLTC structure is the combined type and is composed of diverter switch and tap selector.OLTC is installed on the top cover of transformer by its head flange, and connected to motor drive unit through the upper gear box on the cover of OLTC, bevel gear (auxiliary devices) and driving shaft (horizontal & vertical), realizing the switching operation of OLTC by motor or remote control.

This operation instruction includes all the necessary information for the installation and operation of OLTC. The structure is subject to change without notice.


The operating condition of OLTC

a. The temperature of oil in which the tap changer operates is - 25ºC ~ 100ºC .

b. The ambient temperature under which the tap changer operates is - 25ºC ~ 40ºC .

Mechanical operating principle of the tap changer

Tap change operation begins with the motor of motor drive unit, the driving force is transmitted to the bear gear box through the vertical driving shaft, then transmitted to the retarding mechanism on the head flange via the horizontal driving shaft, and its output shaft drives the insulation shaft rotate. The rotation of insulation shaft then drives the main driving system to operate the spring accumulation mechanism (the energy released from the energy-storing mechanism drives the diverter switch operate), and the Geneva wheel mechanism of tap selector, the rotating of Geneva wheel mechanism makes the singular or dual moving contact of tap selector rotate one operating position.


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