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MWB
:
3658
: +86-21-54720088( )
+86-21-54726918( )
: +86-21-54723118
: 200245
Trench ChinaMWB (Shanghai) Co.,Ltd.No.3658 Jiangcheng Rd.Minhang Economic andTecnnological DevelopmentZone Shanghai P.R.ChinaTel: +86-21-54720088
Fax: +86-21-54723118E-mail: [email protected]: 200245
+86-21-54726918
GIS
Instrument Transformer for Gas-insulated Switchgear
GIS
( )
MWB
The Voltage instrument transformers for GIS have graded insulation for phase-to-
ground connection used in sealed SF6 gas-insulation of plastic films between the layers
of the winding. According to the highest voltage of electric power system, the hightest
system voltage ( Um ) of instrument transformers varies from 72.5kV up to 55 kV
The major components of the transformers:
the housing, consisting of the metallic tank, the coupling flange and the cover.
the active part, consisting of the core, the secondary windings and the primary winding
(with high-voltage electrodes) and high-voltage conductor.
the HV insulator(spacer).
The metallic tank is provided with lifting eyes, ground terminal, the rating plate and
the secondaryterminal box.
The tank and cover are mormally of welded sheet steel or aluminum casting con-
struction. The construction and dimensions of the coupling flange can, within certain
limits, be connected to the GIS flange directly or over an intermediate flange.
The active part is set in the center and bolted to the plate welded on the tank wall
by the core-pressingframe. Sometimes the active part is directly fixed on the cove.
The connection between the higt-voltage conductor and the high-voltage electrode is
made by flexible elements.
The high-voltage insulator serves as a barrier between the gas compartment of the
transformer and the gas compartment of seitchgear. Provided that the same type of
insulating gas is contained in the transformer and the switchgear-which is normally
the case-the two gas compartments are connected with each other using an external
piping. For this purpose, the tank or cover is provided with filling valve.
The secondary windings and earthing terminal of primary wind are brought out
from the tank via a gas-tight multi-bushing into the terminal box where they are con-
nected to the terminals . The terminal box offers ample space for operation. It is
designed for outdoors.
Shock indicator or pressure relidf device can be arranged on the transformer in case
of necessary.
The transformers can be installed in vertical (floor-mounted or suspended) or horiz-
ontal position.
Trench ChinaMWB (Shanghai) Co.,Ltd.
Custom-designed instrument transformers for each specific application
The three windings ( one primary winding, one sefcondary winding , one residual
winding) or four windings (one primary winding, two secondary windings , one resi-
dual winding) are designed as custom requirement.
Instrument transformer is filled with SF6 up to rated pressure after installation as
the nameplate.
Guaranteed SF6 leakage rate is less than 1% per year
Guaranteed moisture in gas shall not exceed 150ppm
Equipped with pressure relidf disc , Pressure relief location may be selected by
customer
Instrument transformer is transported, lifted and overturned in direction indicated
on the rating plate.
Accuracy classes in accordance to IEC 186 or other standards
Features
Technical data
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